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FORM ONE CHEMISTRY NOTES

CHAPTER ONE:INTRODUCTION TO CHEMISTRY AND LABORATORY
TOPIC 1: INTRODUCTION TO CHEMISTRY

Introduction To Chemistry

When you were in primary school, you used to learn science as a single subject. At this level of study, the subject will be broken up into three related subjects, namely Chemistry, Biology and Physics. The three subjects are closely related. You will require the knowledge of one subject to study the other. For example, you will apply the knowledge of chemistry to study different chemical reactions that take place in the body for studying biology of the human body, etc. Likewise as a biologist, you will need the knowledge of physics to study movements of different limbs of the body, etc. Therefore, these few examples show how the three subjects are interdependent. Chemistry is usually studied along with other related subjects such as biology, physics, earth sciences and mathematics. A person studying science is called a scientist. A scientist specialized in the study of chemistry is called a chemist.

The Concept of Chemistry

Explain the concept of Chemistry

Chemistry is a branch of science that deals with the study of nature, properties and composition of matter. Matter can be defined as anything that has weight or mass and can occupy space. Therefore, in chemistry we study materials that make up the earth and universe. These range from living to non-living materials. We apply the knowledge of chemistry to study the composition, behaviour and nature of materials around us. This study enables us to make the best use of these materials to improve our welfare.

Materials Objects Made by Application of Chemistry

Mention materials objects made by application of chemistry

Chemistry is such an important subject that it is applied in other fields such as agriculture, manufacturing, medicine, processing and food industries, education, cosmetics and home care industries, etc. All these industries are responsible for the production of materials that we need to support and hence improve our lives. Materials made by the application of chemistry knowledge include soap, chalk, shoes, clothes, petroleum products, alcoholic and non-alcoholic beverages, cosmetics, drugs, and many others. Can you mention some of the materials made by the application of chemistry knowledge?

This, therefore, means that chemistry is applied in factories, homes, hospitals, pharmacies, research centers, higher learning institutions, etc.

Many products made by the application of chemistry in industry are all around us. Some of these materials are summarized in the table:

Some products made by application of chemistry

Field where applied	Examples of products
Medicine	Drugs, vaccines, nutritional supplements
Agriculture	Agro-chemicals ( fertilizers, pesticides, herbicides, acaricides), animal drugs and vaccines, animal feed and supplements
Manufacturing industry	Vehicles, cement, plastics, chemicals, paints, iron sheets, vanishes, glue
Food and beverage industry	Soft and alcoholic drinks, baked food, canned food, spices, cooking oil, salt
Home care and cosmetics industry	Cosmetics, detergents, toothpaste, shoe polish, insecticides, antiseptics, disinfectants
Transport	Fuels, lubricants, oil, grease, tar, coolants, tyres
Textile industry	Clothes, dyes, bleaches, wax, threads
Leather industry	Shoes, handbags, belts, leather articles

The importance of chemistry in life

Areas Where Chemistry is Applied

Mention areas where chemistry is applied

In everyday life, we need different substances to meet our basic human needs like food, shelter, clothing, comfort and health. Application of chemical knowledge enables the production of different materials and products that we need to live better.

Examples of these materials, as mentioned early, are (paraffin), sugar, common salt, soft drinks, medical drugs (medicines), toothpaste and plastics. Others are spirits, wines, shoe polishes, cement, baking soda, petrol, diesel and cosmetics (soaps, body oils and lotions, body and hair creams, etc)

All these materials, among others, are made by applying chemical processes. They are needed for a better living. Can you mention more materials made through chemistry knowledge?

Some materials made by application of chemistry

Nature is made of materials that may be useless, less useful and even harmful. There are also things that are very useful to our lives. Through chemistry, we are able to transform (change) various materials chemically or physically into forms or products that are more useful to man

For example, most laboratory chemicals you use at school are prepared from minerals that are mined from the rocks in the earth.

Laboratory chemicals

Man cannot use most substances unless they are transformed into products that are more useful. Limestone lying idle in earth is useless until it undergoes deliberate physical and compositional transformation into cement. The cement is used for construction of buildings, roads, bridges and many different structures.

We also need to change different mineral ores through a number of processes into useful substances such as steel, aluminium, tin, etc. Man has learned how to change harmful substances into useful products since the long ago.

Common salt may be made from twohazardous substances–hydrochloric acid and sodium hydroxide.

Chemistry is all around us. We often use chemical products and engage ourselves in chemical processes more than we can tell. Look at the picture below.

This is an example of a chemical activity in which we can engage ourselves without knowing.

A woman washing clothes

Many items we use at school, home and industry are made by applying chemical processes. The soap we use to wash our clothes and clean our bodies is made from animal fat and an alkali. Many items are made from plastic. Many kinds of plastics are made from crude oil. What items are made from plastics in your home? Soft drink bottles are made from glass. The major component of glass is sand. Glass is made by mixing sand with metal oxides in a furnace at high temperatures. Some clothing is made from natural fibers such as cotton or silk.

Other fabrics like polyester and nylon are made from chemicals found in coal and crude oil. What are your clothes made of?

Clothes made from cotton fibres

Man has used medicines extracted from plants and animals since the beginning of time. For example, cinchona tree contains quinine, which has a bitter taste. Quinine was and is still used for treatment of malaria. Penicillin is extracted from a fungus called penicillin. Nowadays, it is possible to make chemicals that have the same effects as naturally occurring drugs.

This forms the basis of the pharmaceutical drugs industry. What medicines extracted from plants and animals are used in your school or local dispensary?

Injection drugs and vaccines are made from plant or animal extracts

Apart from clothing, it is a tradition to put on shoes and other attire. Rubber shoes are made from rubber. Rubber is a sticky milky fluid obtained from certain tropical trees. Skin shoes and handbags are made from skins and hides of animals. The process of converting these raw materials into the items mentioned above involves chemistry knowledge.

What other items made by chemical processes do you know?

Skin shoes

Sustainable crop and animal production is also enhanced by application of chemistry knowledge. The use of chemicals in agriculture is inevitable. Fertilizers, insecticides, acaricides, herbicides (weed killers) have and are still playing a good role in agricultural and animal production. In some ecological zones, in order to get good harvest, fertilizer, herbicide and insecticide application is necessary. The same case applies to animal production. As regards to control and prevention of tick-borne diseases, application of different acaricides is often stressed. Also is the use of different drugs to treat internal parasites such as worms, and vaccines to prevent certain diseases.

The Importance of Chemistry in Daily Life

State the importance of Chemistry in daily life

There are a number of reasons for studying chemistry. If you ask someone to tell you the reason for studying chemistry, he/she will give reasons based on how the subject touches him/her. However, there are general and universal reasons as to why we should devote our valuable time and energy to the study of chemistry. In general, we study chemistry because it helps as to understand:

the composition of materials around us;
the nature, properties and behaviour of these materials;
why and how materials behave as they do;
how a new material, based on the known properties of its allies or counterparts might behave;
how to make new materials which will be useful to us; and
how to extract and use materials from the earth to improve our welfare.

In economic and occupational terms, we can say that the knowledge of chemistry helps us:

to produce professionals in different disciplines such as pharmacy, engineering, medical and natural science professions; and
make items, goods and materials for sale such as chemical laboratory equipments and reagents, medicines, rubber, cement, paints, steel, plastics, etc. What other materials do you think can be included in the list?

Therefore, we can summarize that the study of chemistry is important for survival, development and welfare of man as well as sustainable production of crops and animals.

TOPIC 2: LABORATORY TECHNIQUES AND SAFETY

A laboratory is a room or building specially designed for conducting various scientific experiments. An appropriate school laboratory has the following features:

a room with enough space for carrying out scientific experiments;
a store for keeping laboratory apparatus, chemicals and reagents;
an office for laboratory technician to sit in and design scientific experiments;
enough ventilation to let in fresh air and light;
wide doors and several exits for emergency evacuation in case of an accident; and
a wide table in front of the laboratory room, fitted with sinks for experiment demonstrations by the teacher or technician.

Rules and safety precautions in a chemistry laboratory

laboratory Rules

State laboratory rules

Chemistry is best studied through doing experiments. Most experiments are conducted in the laboratory. It is important to read and follow laboratory rules to avoid causing accidents. Your teacher will teach and give you more rules. The following are some important laboratory rules:

Do not enter the laboratory without permission from your teacher or laboratory technician.
Wear safety goggles all the time while in the laboratory. Obey this rule whether you are actually working on an experiment or simply writing in your laboratory notebook.
Contact lenses are not allowed. Even when worn under safety goggles, various fumes may accumulate under the lens and cause serious injuries or blindness.
Put on closed shoes and trousers when in the laboratory. Sandals and shots are strictly prohibited.
Never walk or run unnecessarily in the laboratory.
Tie back long hair when using open flames.
Eating, drinking, and smoking are strictly prohibited in the laboratory.
Don’t perform any experiment not authorized by your teacher or lab technician. If you are curious about trying a procedure not covered in the experimental procedure, consult your teacher or laboratory technician.
Never taste anything. Never directly smell the source of any vapour or gas; instead drift a small sample to your nose. Do not inhale this vapour directly but take in only enough to detect an odour if one exists.
Always wash your hands after experiments.
Never use your hands to transfer chemicals. Use a spatula instead.
Notify your teacher or technician immediately in case of an accident
Know what chemicals you are using, carefully read the label twice before taking anything from the reagent bottle. Do not interchange labels.
Excess reagents are never to be returned to stock bottles. If you take too much, dispose of the excess.
Many common reagents, for example, alcohol, acetone and carbon disulphide are highly flammable. Do not use them anywhere near open flames.
Pour more concentrated solutions into less concentrated solutions to avoid violent reactions. For example, always add acid to water; not water to acid. If you pour water into acid instead, the heat of reaction will cause the water to explode into steam, sometimes violently, and the acid will splash.
If chemicals accidentally splash onto your skin or eyes, flush immediately with plentiful amounts of water and report to your teacher or lab technician.
Never point a test tube or vessel that you are heating at yourself or your colleague.
Dispose of chemicals properly. Unless you are told otherwise, assume that only water may be poured in the laboratory sinks.
When an experiment is completed, always clean up your work area and dispose of the broken glass properly. Return all equipment to its proper storage places.
Never take away anything from the laboratory without your teacher’s permission.
Beware of hot glass because it looks exactly the same as a cold glass. Never touch it with your hand.
Always adjust the Bunsen burner to give a luminous flame when not using it (or just simply turn it off).
Use equipment or apparatus only for its designated use.
Never eat or drink from laboratory glassware.
Make sure all the burners are turned off before leaving the laboratory. Check that the gas tap is off as well.
Never heat a liquid in a closed container. The expanding gases produced may blow the container apart, injuring you or others.
Use only those chemicals needed in the activity. Keep all lids closed when a chemical is not used.
Do not use the same spatula to remove chemicals from two different containers. Each container should have a different spatula.
Replace all stoppers, covers and caps as soon as you finish using it. Be careful not to exchange stoppers from two different containers.
When heating glassware, use wire gauze or ceramic screen. This will protect glassware from the flame of a Bunsen burner.
Never use broken or chipped glassware. If glassware breaks, inform your teacher and dispose of glassware in the litter bin.
Keep all windows open for proper ventilation.
When carrying out the experiment where you expect harmful gases to be produced, use the fume chamber. The fume chamber helps to disperse hazardous gases and vapours safely.
Use a lighter or wooden splint to light burners. Do not use papers. Always strike the match before turning on the gas supply.
In case of a gas leakage, turn off the gas tap and open the windows. Leave the room immediately.
Do not touch any electrical equipment with wet hands. 36. Turn off any gas or water taps that are not in use.

The Safety Measures for a Chemistry Laboratory

Explain the safety measures for a chemistry laboratory

The chemistry laboratory can be a place of discovery and learning. However, by the very nature of laboratory work, it can be a place of danger if proper common-sense precautions are not taken. Effort has been made to eliminate the use of explosives, highly toxic and carcinogenic substances from the experiments which you will perform. However, there is a certain unavoidable hazard associated with the use of a variety of chemicals and glassware. You are expected to learn and adhere to all safety guidelines. This will ensure a safe laboratory environment for yourself and the people you may be working with or those near you. The following are important laboratory safety measures to obey:

Label and lock all storage areas, cupboards, drawers, storage cabinets, refrigerators, etc. Locking will prevent accidental contact with chemicals or interference with equipment.
Be familiar with the location, use and limitations of the safety devices. This includes fire extinguishers, fire blankets, fume hood, spill cleanup materials, first aid kit, eyewash stations and fire alarm.
Keep all chemicals in properly labelled containers. This will prevent accidental use of the wrong chemical for a particular experiment.
Be familiar with the appropriate safety measures to take when exposed to different hazardous materials. Information is available from your teacher or laboratory technician.
All chemicals that react with each other must be stored separately.
Be aware of the interaction of laboratory furniture and equipment with chemicals used or stored in the laboratory. For example, oxidizers should not be stored directly on wooden shelves.
Use fume hoods/cupboards/chambers whenever possible.
Never store food in a refrigerator or freezer where hazardous chemicals are stored. Also, do not eat anything you find in the laboratory or in the laboratory freezer or refrigerator.
Make sure fire extinguishers are in good condition. Report any broken seals, damage, low gauge pressure or improper mounting to the teacher or laboratory technician. If the seal has been broken, assume that the fire extinguisher has been used and must be recharged. (Note: Do not use fire extinguishers unless you are trained and feel confident to do so).
Stored chemicals must be inspected regularly to ensure they have not expired. Note the date when bottles were received and when were first opened. Note expiry dates on chemicals and their special storage conditions.
Eliminate safety hazards by maintaining laboratory work areas in a good state of order.
The laboratory must have wide emergency exits and wide windows. Wide exits facilitate easy evacuation in case of emergency. Wide windows allow enough air to enter and circulate in the laboratory. (Note: Maintain at least two clear passages to laboratory exits).
Always keep tables, seats, fume hoods, floors and desks clear of unnecessary material.
All equipment should be inspected before use. In addition, they should be checked regularly to ensure they are safe for use.
If experiments must be left unattended, place a note next to experimental apparatus indicating the chemicals involved, your name and telephone number on which you can be reached in case of an emergency.
Keep the laboratory floor clean and dry at all times. Clean spills of water or chemicals immediately. Then notify other laboratory workers of potential slipping hazards.
The laboratory must be equipped with potable fire extinguishers and other safety devices with clear instructions on how to use them in case of any emergency.
Containers for holding or storing chemicals must be inspected for leakages or other damages. They should have tight stoppers or covers.
All experimenters and other persons working in the laboratory should wear protective gears to minimize exposure to hazards. These gears may include lab coats, hand gloves, gumboots, safety goggles, aprons, etc.
There should be a manual or instruction guides on how to treat spills of different chemical substances.
The fume chamber should be labelled. It should be kept in good condition to minimize unexpected gas leakages or emissions.
Gas cylinders should be labelled, stored properly, and supported. Moreover, they should be in good working conditions all the time.
Each laboratory should be equipped with adequate first aid kits.
Equipment for monitoring contamination should be installed to give alerts of any possible dangers.

NOTE: All the above rules and safety measures are applicable to all research, teaching and academic laboratories. However, your laboratory may require some more rules that apply to specific materials and equipment.

First aid and first aid kit

FIRST AID

First aid is the help given to someone who is injured or sick before the victim gets further medical assistance. This help can be given by any person regardless of his/her knowledge in a medical profession.

Whenever an accident occurs, something must be done immediately to help and save life of the victim. You must always be ready to give a hand to a victim whenever an accident occurs close to you. To give aid effectively and successfully, one must have elementary knowledge on how to assist different victims. If you do not know how to help a certain victim, you can ask someone to assist instead. Do not engage yourself in assisting if you actually do not know where to start. You may find yourself worsening the situation of the victim unknowingly. However, this should not be taken as an excuse for failing to help. Always be ready to render some kind of help. First aid helps to:

relieve pain and bring hope to the victim.
prevent permanent disability
prevent the victim’s condition from getting worse
reduce the possibility of death.
shorten recovery time

Possible Causes of Accidents in a Chemistry Laboratory

Identify possible causes of accidents in a chemistry laboratory

Accidents may occur in a school laboratory if utmost care is not taken into account. Accidents in the laboratory are mainly cuts on parts of the body such as hands, fingers, legs or head. Others are burns from flames, scalds from boiling fluids, bruises and grazes due to accidental falling on a slippery floor.

Some possible causes of accidents in the laboratory include:

Failure to follow the correct experimental procedures for example, pouring water into an acid instead of pouring an acid into water as the rule is.
Neglecting some laboratories rules such as ignoring to wear protective gears, tasting the chemicals, eating or drinking while in the laboratory, etc.
Failure to adhere to proper conduct in the laboratory like running unnecessarily and conducting experiments without your teacher's or technician's permission and guidance.
Improper use or handling of laboratory equipment and apparatus when conducting experiments, which could lead to breakage and in turn cause cuts, bruises, grazes, etc.
A slippery laboratory floor which can cause fractures, cuts, bruises, grazes, etc
Accidental spillage of chemicals on body parts such as hands, face, eyes, etc, could lead to burns and damage.
Poor ventilation in the laboratory may cause suffocation (due to inadequate oxygen supply) and poisoning (by inhaling poisonous gases produced when experimenting).
Improper disposal of chemical wastes may result in explosions, burns or even fires.
The leaking of gases from taps or cylinders may cause fires or even explosions.
Use of wrong reagents due to incorrect labeling of chemicals or use of reagents or chemicals that have expired may cause burns, poisoning or damage to apparatus or equipment.
Inadequate prior information or knowledge on procedures and hazards associated with certain practical activities or reactants may result in burns, poisoning or explosions.
Loose or improperly plugged electrical appliances may cause electric shock, especially when touched with wet hands and during fixing of sockets.

In general, it can be concluded that most laboratory accidents are a result of negligence and carelessness of experimenters. It is also due to failure to follow the laboratory rules and general safety measures.

The Items Found in a First Aid Kit

Name the items found in a first aid kit

A First Aid Kit is a box in which first aid chemicals, tools and instruments are kept. In the laboratory, the box is usually kept in a place where it can be easily reached in case of an accident, preferably on the wall.

Each student must be familiar with the tools and chemicals kept in the kit and learn how to use them to provide first aid to a victim.

First aid kit and its contents

How Each First Aid Kit Item is Used

Demonstrate how each first aid kit item is used

The table below shows types of chemicals found in a First Aid Kit and their functions.

Tool/chemical/item	Function
First aid manual	Contains guidelines on how to use the items in the first aid kit
Sterile gloves	Worn on hands when attending bleeding cuts or wounds to avoid infecting wounds and to prevent direct contact with the victim’s body fluids
Sterile dressing	Stops bleeding
Antiseptic agent	Cleaning and disinfection of wounds, cuts, bruises, grazes or blisters
Soap	Washing hands, wounds and equipment
Antibiotic ointment	Prevents infection on cuts and bruises in or near the eye
Burn ointment	Applied on burns to prevent infection
Petroleum jelly	Soothing broken skin
Plaster or adhesive bandage	Covering small wounds or cuts
Sterile gauze	Covering wounds to protect them from dirt or germs
Eye wash solution	Flushing the eyes or as a general decontaminant
Thermometer	Recording body temperature
Antibiotic towelettes or cotton wool	Cleaning and drying cuts and wounds
Iodine tincture	Dressing fresh cuts and bruises
Pain relieving drugs such as aspirin, paracetamol, panadol, etc	Relieving mild pains
Liniment	Reducing muscle pain
Mild antibiotics	Treating mild bacterial infections on the skin, ear, nose and mouth
Gentian violet solution	Applied on minor wounds and treatment of serious heat wounds
Hydrogen peroxide solution	Cleaning wounds
Methylated spirit (70% alcohol)	Cleaning cuts and bruises
Bandages	Dressing wounds and cuts, and immobilizing injured limbs
Scissors or razor blade	Cutting dressing materials
Dental kit	Treatment of broken teeth, loss of crown or filling
Safety pins (small and big)	Splinter removal and securing triangular bandage slings
Tweezers	Splinter or stinger removal
Resealable oven bag	Container for contaminated articles
Moleskin	Applied to blisters or hot spots
Triangular bandage	Used as a sling, towel or tourniquet
Boiled, clean water	Washing hands and drinking
Nasal spray decongestant	Nasal congestion from colds or allergies
Torch	Source of light
Whistle	Blown to call for help

The Items in a First Aid kit to Provide First Aid to an Accident Victim

Use the items in a first aid kit to provide first aid to an accident victim

First aid procedures

Sometimes accidents may occur in the laboratory due to some reasons or the other. Whenever an accident occurs, one must be ready and prepared to assist. The following are some of the health problems that may require first aid and the procedure to follow when providing help.

Bleeding

Bleeding is the loss of blood from the body and usually occurs from a visible wound. Bleeding may be external or internal. It may from artery, vein or capillary. Bleeding may be severe or light. Excessive loss of blood may cause death.

(a) Internal bleeding

Signs and symptoms of internal bleeding include the following:

Bruised, swollen, tender or rigid abdomen
Bruises on chest, neck, legs or signs of fractured ribs
Vomiting or coughing up blood.
Wounds that have penetrated the skull, chest or abdomen
Bleeding from body cavities such as the ears, nose, rectum or vagina
Abdominal pulse and difficulty breathing
Cool, moist skin
Fractures

Procedure

First aid in the field for internal bleeding is limited. If the injury appears to be a simple bruise, apply cold packs to slow down the bleeding, relieve pain and reduce swelling.
If you suspect more severe internal bleeding, carefully monitor the patient. Be prepared to administer CPR if required (and you are trained to do so).
Seek medical advice immediately if the situation seems to be worse.

(b) Severe bleeding

Procedure

Severe bleeding with blood oozing out rapidly must be stopped at once. This can be done by applying direct pressure to the wound. Use a dressing if available. If it is not available, use a rag, towel, piece of clothing or your fingers alone. If the wound is large, press the edges of the wound together but firmly. However, this should be done only if there is no fracture.
Lay the victim down in a comfortable position.
If the wound is on a limb, and provided it is not fractured, raise the wound above the level of the heart. Then continue to apply direct pressure. This should be done only if bleeding continues and if it does not cause pain.
If bleeding still cannot be controlled, the next step is to apply pressure at a pressure point. For wounds of the arms or hands, pressure points are located on the inside of the wrist (radial artery-where a pulse is checked) or on the inside of the upper arm (brachial artery). For wounds of the legs, the pressure point is at the crease in the groin (femoral artery).
When bleeding stops, clean the wound carefully and thoroughly with a suitable disinfectant. Do not remove any objects stuck in the wound, as this would lead to more bleeding.
Place sterile gauze on the wound and press it down firmly. Cover it with a soft material and hold it in position using a firm bandage. After the bandage is in place, it is important to check the pulse to make sure blood circulation is not interrupted. A slow pulse rate, or bluish fingertips or toes signal a bandage may be hindering blood circulation.
Seek medical help immediately.

Important: Once pressure is applied, keep it in place. If dressings become soaked with blood, apply new dressings over the old dressings. The less a bleeding wound is disturbed, the easier it will be to stop the bleeding.

(c) Light bleeding

Procedure

Place the victim in a comfortable resting position.
Elevate the injured part while applying pressure. This should be done only if the wound is on a limb and you do not suspect a fracture.
Gently and thoroughly clean the wound using water and antiseptic or common salt solution.
Cover the wound with sterile gauze or clean dressing dipped in iodine solution.
Dress and bandage the wound
Take the victim to hospital if bleeding still continues.

(d) Nose bleeding

Bleeding usually occurs near the tip of the nose. The bleeding may be a result of high blood pressure, rheumatic fever, or injury. Nose bleeding is also likely to occur at high altitude because of low atmospheric pressure or extreme coldness.

nose-bleeding victim

Procedure

Let the victim sit calmly. This makes the heartbeat to slow down and hence reduce bleeding.
Loosen clothing around the neck and chest.
Let the victim sit upright and lean the head forward slightly. By remaining upright, the victim reduces the blood pressure in the veins of his or her nose. This discourages further bleeding. Leaning forward will help the victim avoid swallowing blood, which can irritate his or her stomach.
Have the victim pinch his or her nose, to keep nostrils shut, using thumb and index finger. Ask the victim to breath through the mouth. Let him or her continue pinching for a few minutes.
Apply cold, wet compression over the nose, face and at the back of the victim’s neck.
When bleeding stops, gently clean the nostrils.
If bleeding does not stop after 20 minutes, take the victim to the hospital immediately.
To prevent re-bleeding after bleeding has stopped:
Ask the victim not to pick or blow the nose and not to bend down until several hours after bleeding.
Let the victim keep his/her head higher than the level of his/her heart.
If re-bleeding occurs:
Ask the victim to blow out forcefully to clear the nose of blood clots. Spray both sides of the nose with decongestant nasal spray.
Pinch the nose as described above and seek medical help.

nose-bleeding victim with his head leaned forward.

Suffocation

Suffocation is a condition in which the lungs are not getting enough oxygen, causing difficulty in breathing. In such cases, foams can also appear in the mouth and nostrils. If suffocation is complete (no air at all reaches the lungs), the lack of oxygen and excess carbon dioxide in the blood will cause immediate loss of consciousness. Though the heart continues to beat briefly, death will follow in a matter of minutes unless emergency measures are taken to get breathing started.

Suffocation can be caused by drowning, electric shock, gas or smoke poisoning, choking, asthma, severe infections of the throat or other causes.

Procedure

Remove the cause of suffocation or remove the victim from the cause of suffocation. Loosen tight clothing around the neck.
Make sure the victim’s airway is open for air to reach the lungs. This can be achieved by laying the victim on his or her back. Then, with one hand on the victim’s forehead and the other on the chin, tilt the head backwards, to open the airway. Tilt the head until the chin points straight upwards. If the airway is blocked by fluid or solid, remove it.
Administer cardiopulmonary resuscitation (CPR). This involves blowing air into the victim’s mouth (mouth-to-mouth breathing). To do this, pinch the nose and close up the mouth. Take a deep breath and then blow hard into the victim’s mouth. Watch the rise in chest and repeat the procedure until the victim’s breathing is restored. In case the person does not respond, go for chest compressions.
Compressions can be done by placing the palm of one hand in the space between the nipples and the other hand over it and pushing the chest by using your upper body weight. Care should be taken to prevent chest injury or fracture. Two compressions can be given every second or hundred per minute. After thirty compressions, go for mouth breathing again. Repeat the procedure until natural breathing is restored.
Keep the casualty warm using a light blanket.
Take the casualty to the hospital immediately.

figure.

Choking

Choking occurs when food or a foreign object blocks the upper part of the windpipe. This interferes with normal breathing. The signs of this problem include difficulty in breathing and speaking. Have you ever been with a person who is chocking? Did you know what to do?

When attending a person who is chocking, first notice whether the person can talk, breathe or cough. Caution: Do not try to slap the person on the back. The slapping may only cause the food to become more deeply lodged in the airway.

Procedure

Ask the victim to cough up the object.
If the object remains stuck, give firm but gentle taps between the shoulder plates.
If the object is still stuck, apply quick abdominal thrusts i.e. Heimlich manoeuvre as follows:
Stand behind the victim and make him or her lean forward slightly.
Put your arms around the person, placing your fist just below the breastbone. Grasp your fist with the other hand near the top of the victim’s stomach.
Press your fist onto the victim’s abdomen. Give a series of quick, sharp upward and inward thrusts to dislodge the object.

Thrusting to dislodge the object

Poisoning

A poison is any substance that can harm the body or seriously endanger health when taken into the body. A poison may get into the body through inhaling, swallowing, wounds or skin cuts or absorbed into the body in other ways. Potential poisons include poisonous fumes (or gases), laboratory chemicals or even medical drugs and medicines.

In every household, there are different kinds of things that are poisonous. Some are deadly even on a very small dose. Others may be more or less harmless when taken in small quantities.

Examples of poisonous substances at home are kerosene, disinfectants, paints, medicines, artificial fertilizers, etc.

Some signs and symptoms of poisoning are nausea, vomiting, abdominal cramps, pain, difficulty breathing, diarrhea, and abnormal skin colour. Others are breath that smells like the chemicals, chemical burns, empty medication bottles or scattered pills, sleepiness, confusion or other unexpected signs.

Procedure

Call for medical help immediately if the person shows one or some of the following signs: drowsy or unconscious; having difficulty breathing or has stopped breathing; uncontrollably restless or agitated.
For the time being, find out what caused the poisoning, i.e. look for the poison and identify it.
If the person has been exposed to poisonous fumes such as carbon monoxide, get him or her to where there is fresh air immediately.
If the poison is in the eye:
Wash the eye with a lot of clean water.
Ask the victim to blink as much as possible.
Do not rub the eye.
If the person swallowed the poison:
Remove anything remaining in the mouth
Induce vomiting if the poison is not strong acid or alkali as these are corrosive substances. Non- corrosive substances include medicines and soaps. Vomiting can be induced by inserting your finger in the victim’s throat until the finger touches the epiglottis.
Do not induce vomiting if the poison swallowed is corrosive. Corrosive substances include kerosene, bleach, detergent, laboratory acid, disinfectant or certain toiletries. If the suspected poison is a household cleaner or other chemical, read the label and follow instructions for handling accidental poisoning.
Neutralize the poison by giving the victim plenty of milk to drink, an egg white or water.
If the poison is on the skin:
Remove any clothing from the affected part.
Wash the affected area thoroughly with a lot of water.
Do not apply any ointment.
Make sure the person is breathing. If not, start rescue breathing and CPR.

Note: Take the poison container or any pills, pill bottle or pill blister pack with you to the hospital.

Shock

Shock is a condition in which the body system fails to take enough blood to the vital organs. If untreated, it can lead to permanent organ damage or death. The vital organs include the heart, the lungs, the brain, the kidneys and the liver.

Causes

Shock may result from bad news, heatstroke, severe illness, blood loss, dehydration, poisoning, severe burns, an accident or other causes.

Signs and symptoms

Various signs and symptoms appear in a person experiencing shock. They include the following:

The skin becomes cool and moist. The skin, lips and fingernails may appear pale or grey.
The pulse rate is weak and rapid. Breathing may be slow and shallow.
The limbs may tremble and get weak.
The eyes lack lustre and may seem to stare. Sometimes the pupils are dilated.
As the shock develops, the victim may experience nausea and even vomiting. Eventually he or she may become restless, nervous, aggressive and finally conscious or unconscious. If conscious, the person may feel faint or be very weak or confused.

Procedure

Control any cause of shock such as bleeding, etc.
Lay the person down with his or her feet higher than his or her head (shock position).
Loosen tight clothing, laces, belts and shoes.
Turn the person on his or her side to prevent choking if the person vomits or bleeds from the mouth.
Keep the person warm and comfortable if he/she feels cold. Cover the victim with a blanket or any heavy clothing.
Seek treatment for injuries such as bleeding or broken bones.
Administer CPR if the person does not appear to breath well, cough or even move.
Seek medical help immediately.

The shock position

Electric shock

An electric shock occurs when a person comes into direct contact with electricity. Exposure to electricity may result in injury or even death. Injuries may be burns, or physical injuries that result from being thrown by the electric current.

Procedure

Switch off the main switch immediately if possible.
If not possible to put off the switch, detach the casualty from the source of electricity using a non-conducting object such as a dry wooden stick, cardboard, plastic or rope.
Loosen any tight clothing, necklaces, bangles, etc.
If the person is unconscious, apply mouth-to-mouth respiration (CPR) immediately.
Treat for shock, burns, bruises or other injuries the victim may have sustained. Lay the victim down, and if possible, position the head slightly lower than the trunk, with the legs elevated (shock position).
Take the person to the hospital immediately.

Caution

Do not touch the person with your bare hands if he or she is still in contact with the electric current.
Do not get near high-voltage electricity until power is turned off. Instead, call for help immediately.
Do not move a person with an electrical injury unless the person is in immediate danger.

Bruises

A bruise is an injury beneath the skin. Bruises can be identified by pain, swelling or a mark under the skin. A bruise forms when a blow (hard hit) breaks the blood vessels near the skin’s surface. This allows a small amount of blood to leak into the tissues under the skin. The trapped blood appears as a blue-black mark.

Procedure

Wash the bruised part of the body.
Apply a cold compress, such as a cloth dipped in cold water or ice wrapped in a cloth, to the injury. This helps reduce pain, swelling, and speeds up recovery.
If the bruise is on a limb such as arm or leg and it covers a large area, keep the limb elevated as much as possible for the past 24 hours.
After 48 hours, apply a cloth dipped in tepid water to the bruise for about 10 minutes, three times a day. This will help increase blood flow to the affected area and thus speed up healing.

Bruises under the skin

Vomiting

Vomiting is an involuntary ejection of the contents of the stomach through the mouth.

Possible causes of vomiting

Allergic reactions
Diseases e.g. malaria
Physiological condition e.g. pregnancy
Food poisoning
Unpleasant smell or taste
Drinking contaminated water.
Inhaling poisonous fumes
Over-eating.

Procedure

Give the victim an oral rehydration drink or oral rehydration salt solution. You may also provide a lot of any clear fluids.
Allow the person to have a complete rest.
Take the victim to hospital if:
Vomiting continues persistently.
The victim vomits blood.
The victim experiences high fever.
The victim is very dehydrated. This will be observed when the mouth and skin become very dry.

A victim vomiting

Fainting

Fainting is a sudden loss of consciousness caused by a temporary fall in the supply of blood and oxygen to the brain. Sometimes it can be caused by emotional shock or prolonged standing. The person feels weak, sweats and then falls down.

Procedure

Loosen or remove any tight clothing from the victim.
Make the victim lie down on his or her back.
Raise the legs of the victim (shock position) above the level of his or her head. This will increase the flow of blood to the brain.
Make sure the victim is exposed to plentiful supply of fresh air.
If there is no improvement in a few minutes, rush the victim to the hospital

Caution: Do not try to warm the victim

Muscle cramps

A muscle cramp is an involuntarily and forcibly contracted muscle that does not relax. A muscle that contracts involuntarily is called a ‘’spasm.’’ If the spasm is forceful, it becomes a cramp. Therefore, muscle cramps occur because of uncontrolled muscle spasms.

Signs and symptoms

A sharp, sudden and painful spasm, or tightening of a muscle (especially common in the legs).
Muscle hardness
Twitching of the muscle
Persistent cramping pains in the lower abdominal muscles.

Causes

Imbalance in certain minerals, body fluids, hormones, and chemicals that allow stretching and contracting of our muscles.
Malfunctioning in the nervous system.
Excessive physical activity and hormonal imbalances cause us to sweat. This brings about the loss of many essential minerals, such as potassium and calcium, which our body muscles need.

Procedure

Lay the victim down
Gently massage and stretch out the cramped muscle(s).
Apply some anti-cramp ointment to the affected area
If the problem persists, seek medical help immediately.

Stretching and massaging the muscles

Hiccups

Hiccups are caused by sudden involuntary contraction of the diaphragm muscles, giving a characteristic ‘’hic’’ sound. Numerous cures for hiccups exist. These cures are thought to work because they increase the level of carbon dioxide in the blood, which usually stops hiccups. (See procedure 1-3 below). If the vagus nerve that runs from the brain to the stomach is stimulated, hiccups can also be alleviated.

Procedure

Give the affected person a polythene bag and encourage him/her to re-breath her own expelled air.
Ask the person to drink a glass of cold water quickly.
Tell the victim to hold his/her breath for as long as possible.
Ask the victim to pull on his/her tongue.
The victim may swallow finely crushed ice.
Children can be given a teaspoonful of a weak solution of sodium bicarbonate or lemon juice.
Place one teaspoonful of dry sugar or honey on the back of the victim’s tongue. (You can repeat this process 3 times at 2-minute intervals)

Basic chemistry laboratory apparatus and their uses

Instruments used for carrying out different experiments in the laboratory are called laboratory apparatus. Laboratory apparatus can be classified according to their uses as:

apparatus for holding things e.g. test-tube holder, retort stand and clamp, test-tube rack, tongs and tweezers;
apparatus for taking measurements e.g. thermometer, burette, pipette, measuring cylinder, measuring flask, beam balance, electronic balance, common balance, measuring syringe, beaker and stop watch;
apparatus for heating substances e.g. boiling tube, pipeclay triangle, crucible and lid, wire gauze, deflagrating (combustion) spoon, Bunsen burner, spirit lamp, tripod stand, evaporating dish, wire gauze and stove;
apparatus for doing chemical reactions (or testing) e.g. beaker, test tube, dropper, flask, watch glass, gas jar and thistle funnel;
apparatus for filtering e.g. filter funnel, filter paper and cotton wool;
apparatus for grinding e.g. mortar and pestle;
apparatus for storage e.g. reagent bottles and wash bottle;
apparatus for scooping e.g. spatula; and
apparatus for safety e.g. goggles and hand gloves.

The Apparatus Used in a Chemistry Laboratory

List the apparatus used in a chemistry laboratory

Some chemistry laboratory apparatus

Chemistry Laboratory Apparatus According to their Uses

Categorize chemistry laboratory apparatus according to their uses

The apparatus can also be classified based on materials they are made of. Most of the apparatus are made of glass. Others are made of metal, plastic or wood. Just a few are made of clay and asbestos.

Table summarizes some common laboratory apparatus and their uses.

Composition and uses of some chemistry laboratory apparatus

	Apparatus	Material	Uses
1.	Test tube	Glass	Holding chemicals or, heating substances
2.	Funnel	Glass or plastic	Leading liquids into containers, and for filtration purposes
3.	Beaker	Glass or plastic	Holding, heating, and mixing liquids
4.	Flask	Glass	Holding, heating, and titrations
5.	Retort stand	Metal (iron)	Holding apparatus during heating
6.	Tripod stand	Metal (iron)	Holding apparatus during experiments
7.	Gas jar	Glass	Gas collection
8.	Wash bottle	Plastic	Washing
9	Crucible	Ceramic or non-reactive metal	Heating
10	Test tube holder	Metal and plastic or wood	Holding test tubes while heating
11.	Weighing balance	Metal and plastic	Measuring weight (or mass)
12.	Spatula	Metal	Scooping small quantities of powder or crystalline chemicals
13.	Condenser	Glass	Cooling hot liquids
14.	Pipette	Glass	Accurate measurement of specific volumes of liquids for titrations
15.	Burette	Glass	Titrations
16.	Trough	Glass	Assists in gas collection
17.	Tongs	Metal	Picking and holding hot substances and apparatus
18.	Measuring jar	Glass	Measuring volumes of liquids
19.	Thistle funnel	Glass	Leading liquids into containers and apparatus
20.	Dropper	Glass and rubber	Dropping indicators into reagents
21.	Mortar and pestle	Clay	Crushing or grinding substances
22.	Wire gauze	Metal	Even distribution of heat during heating
23.	Spring balance	Metal	Measuring weight
24.	Distillation flask	Glass	Distillation
25.	Combustion spoon	Metal	Burning powder in jars
26.	Thermometer	Glass and liquid metal	Measuring temperature
27.	Delivery tube	Glass	Allowing gases pass through
28.	Bunsen burner	Metal	Heating substances
29.	Separating funnel	Glass	Separation of immiscible liquid mixtures
30.	Measuring cylinder	Glass or plastic	Measuring volumes of liquids
31.	Measuring syringe	Plastic	Sucking in and measuring specific volumes of liquids
32.	Stopwatch	Plastic or glass and metal	Accurate measurement of time
33.	Watch glass	Glass	Used as a surface to evaporate some liquids, to hold substances being weighed or observed, or as a cover for a beaker
34.	Boiling tube	Glass	Is a large test tube used to heat substances requiring strong heating, or when the sample is too large for a test tube
35.	Evaporating dish	Ceramic	Heating and evaporating liquids and solutions
36.	Filter paper	Paper	Filtration
37.	Test tube rack	Wood or plastic	Placing test tubes
38.	Reagent bottle	Glass	Storing different chemicals
39.	Wash bottle	Plastic	Storing distilled water
40.	Safety goggles	Glass	Protecting eyes from chemical spills, strong light and harmful vapours
41.	Bell jar	Glass	Keeping gases, moisture, air, etc. or creating vacuums

Common Chemistry Laboratory Apparatus

Use common chemistry laboratory apparatus

Common laboratory apparatus

Activity 1

Your teacher will guide you how to measure the volume of liquids using the other apparatuses.

Aim: To measure volume of liquids using different apparatus

Materials: pipettes, burettes, measuring cylinders, water, beakers.

Procedure

Pour some water into a graduated measuring cylinder with a capacity of 100 cm3. Add the water, one drop at time, up to a 25-cm3 mark.
While adding water, position yourself at eye-level with the mark on the cylinder. This will enable you to obtain the most accurate measurement. To simplify the work of reading the level of the water, you may use coloured water.
Select a volumetric flask measuring 50 cm3. Pour the water into the flask until it reaches the mark on the flask’s neck.
Position yourself at eye-level with the mark. You will obtain the most accurate reading when the mark appears straight rather than elliptical. To obtain this, put a flask on a flat table.
Add water one drop at a time. Do so until the bottom of the curved surface of the water exactly matches the mark on the flask.

Activity 1.2

Aim: To measure the masses of solid substances

Materials: chemical, electronic or spring balance, watch glasses, various substances such as sand, sugar, salt, flour, stones, fruits.

Procedure

Put an empty watch glass on the weighing balance. Note down its mass. Record this as mass M1.
Place the various items you have on the watch glass, one item at a time. Note down the mass. Record this as M2.

Note: to obtain the mass of an object, we subtract the mass of an empty watch glass from the mass of the watch glass and the substance. That is, M2 - M1.

For example

Warning signs

Chemical warning signs are safety symbols found on containers, especially those used in the laboratory. The symbols are also found on tanks or containers that are used to carry, store or transport certain chemicals. Containers holding flammable fuels such diesel, petrol and natural gas, as well as those containing toxic chemicals normally bear warning symbols. These symbols indicate the danger (hazard) likely to be caused by the chemicals they contain if carelessly handled.

When performing experiments in the laboratory it is important to read the safety signs on chemical containers. This will minimize the chances of causing accidents in the laboratory.

The Basic Chemical Warning Signs

Draw and label the basic chemical warning signs

Some chemical warning signs

The Concept of Warning Signs

Explain the concept of warning signs

Before conducting any experiment in the laboratory you must be aware whether the chemical you want to use is toxic, corrosive, flammable, oxidant, explosive or harmful. This information will help you know how to handle the chemicals safely. Proper handling of chemicals enables you avoid unnecessary accidents. Below is an explanation pertaining to some hazard labels represented by the symbols above.

Toxic

Toxic substances include those that can poison you or the other person working close to you in the laboratory. These substances can kill within a short time or after some few days. They should not be allowed to get into your body through body orifices (month, nose, eyes, ears, etc). Neither should they be allowed to contact your skin. They become even more dangerous when they get into the body. If it happens that these substances touch your skin accidentally, wash it immediately with ample water.

Corrosive

Corrosive substances refer to those chemicals that can burn or corrode (eat away) your skin. They can also corrode wood or metals. One can become blind if such substances accidentally get into his/her eyes. If they contact your skin, wash it immediately with a lot of water. Examples of corrosive substances commonly found in a school laboratory are concentrated mineral acids such as sulphuric acid, hydrochloric acid and nitric acid, and concentrated alkalis such as sodium hydroxide, potassium hydroxide and ammonia.

Flammable

These chemicals catch fire easily. For this case, they should be kept away from flames or fires. They can be set into fire by any kind of sparks, be it from welding or fire. When working with flammable chemicals in the laboratory all burners must be put off. These chemicals are usually very volatile. The containers used to carry them must be stoppered immediately after every use. Examples of flammable chemicals are methylated spirit, ether, acetone and methanol.

Explosive

Explosive chemicals are those that explode rapidly upon detonation (set into fire or ignited). Because the reaction is rapid, it results into throwing off particles at a high speed. For this reason, they should not be kept in glass containers. This is because during explosion the particles will disperse around and cause serious injuries to people. Those explosive chemicals that can react without external detonation are even more dangerous

Oxidizing agents

These chemicals can stimulate a burning substance to burn efficiently and faster. Therefore, they must be kept away from fires no matter how small that fire may be. An example of oxidizing agent is oxygen gas.

Harmful or irritant

Harmful substances are those that can impair your health or make you fall sick. They do not normally kill instantly but have detrimental effects following a long exposure to them. These chemicals do not kill immediately. However, care must be taken when handling or dealing with them. Irritating substances cause pains when in contact with the body. They are dangerous to health when in contact with the body surface for a long period of time.
OR
Definition; Chemistry is a branch of science that deals with the study of nature, properties and composition of matter.

Matter can be defined as anything that has weight or mass and can occupy space.

Therefore, in chemistry we study materials that make up the earth and universe. These range from living to non-living materials. We apply the knowledge of chemistry to study the

composition, behaviour and nature of materials around us. This study enables us to make the best

use of these materials to improve our welfare.

APLICATION OF CHEMISTRY

Materials/Objects Made by Application of Chemistry

Mention materials objects made by application of chemistry

Chemistry is such an important subject that it is applied in other fields such as agriculture,

manufacturing, medicine, processing and food industries, education, cosmetics and home care

industries, etc. All these industries are responsible for the production of materials that we need to

support and hence improve our lives. Materials made by the application of chemistry knowledge

include soap, chalk, shoes, clothes, petroleum products, alcoholic and non-alcoholic beverages,

cosmetics, drugs, and many others. Can you mention some of the materials made by the

application of chemistry knowledge?

This, therefore, means that chemistry is applied in factories, homes, hospitals, pharmacies,

research centers, higher learning institutions, etc.

Many products made by the application of chemistry in industry are all around us. Some of these

materials are summarized in the table:

Field where applied Examples of products

3.Some products made by application of chemistry

The importance of chemistry in life

Areas Where Chemistry is Applied

Mention areas where chemistry is applied

In everyday life, we need different substances to meet our basic human needs like food, shelter,

clothing, comfort and health. Application of chemical knowledge enables the production of

different materials and products that we need to live better.

Examples of these materials, as mentioned early, are (paraffin), sugar, common salt, soft drinks,

medical drugs (medicines), toothpaste and plastics. Others are spirits, wines, shoe polishes,

cement, baking soda, petrol, diesel and cosmetics (soaps, body oils and lotions, body and hair

creams, etc)

All these materials, among others, are made by applying chemical processes. They are needed

for a better living. Can you mention more materials made through chemistry knowledge?

Medicine Drugs, vaccines, nutritional supplements

Agriculture

Agri-chemicals ( fertilizers, pesticides, herbicides, acaricides), animal drugs and vaccines,

animal feed and supplements

Manufacturing industry Vehicles, cement, plastics, chemicals, paints, iron sheets, vanishes, glue

Food and beverage industry Soft and alcoholic drinks, baked food, canned food, spices, cooking oil, salt

Home care and cosmetics

industry Cosmetics, detergents, toothpaste, shoe polish, insecticides, antiseptics, disinfectants

Transport Fuels, lubricants, oil, grease, tar, coolants, tyres

Textile industry Clothes, dyes, bleaches, wax, threads

Leather industry Shoes, handbags, belts, leather articles

4.Some materials made by application of chemistry

Nature is made of materials that may be useless, less useful and even harmful. There are also

things that are very useful to our lives. Through chemistry, we are able to transform (change)

various materials chemically or physically into forms or products that are more useful to man

For example, most laboratory chemicals you use at school are prepared from minerals that are

mined from the rocks in the earth.

Laboratory chemicals

Man cannot use most substances unless they are transformed into products that are more useful.

Limestone lying idle in earth is useless until it undergoes deliberate physical and compositional

transformation into cement. The cement is used for construction of buildings, roads, bridges and

many different structures.

5.We also need to change different mineral ores through a number of processes into useful

substances such as steel, aluminium, tin, etc. Man has learned how to change harmful substances

into useful products since the long ago.

Common salt may be made from twohazardous substances–hydrochloric acid and sodium

hydroxide.

Chemistry is all around us. We often use chemical products and engage ourselves in chemical

processes more than we can tell. Look at the picture below.

This is an example of a chemical activity in which we can engage ourselves without knowing.

A woman washing clothes

6.Many items we use at school, home and industry are made by applying chemical processes. The

soap we use to wash our clothes and clean our bodies is made from animal fat and an alkali.

Many items are made from plastic. Many kinds of plastics are made from crude oil. What items

are made from plastics in your home? Soft drink bottles are made from glass. The major

component of glass is sand. Glass is made by mixing sand with metal oxides in a furnace at high

temperatures. Some clothing is made from natural fibers such as cotton or silk.

Other fabrics like polyester and nylon are made from chemicals found in coal and crude oil.

What are your clothes made of?

Clothes made from cotton fibres

Man has used medicines extracted from plants and animals since the beginning of time. For

example, cinchona tree contains quinine, which has a bitter taste. Quinine was and is still used

for treatment of malaria. Penicillin is extracted from a fungus called penicillin. Nowadays, it is

possible to make chemicals that have the same effects as naturally occurring drugs.

This forms the basis of the pharmaceutical drugs industry. What medicines extracted from plants

and animals are used in your school or local dispensary?

7.Injection drugs and vaccines are made from plant or animal extracts

Apart from clothing, it is a tradition to put on shoes and other attire. Rubber shoes are made from

rubber. Rubber is a sticky milky fluid obtained from certain tropical trees. Skin shoes and

handbags are made from skins and hides of animals. The process of converting these raw

materials into the items mentioned above involves chemistry knowledge.

What other items made by chemical processes do you know?

Skin shoes

Sustainable crop and animal production is also enhanced by application of chemistry knowledge.

The use of chemicals in agriculture is inevitable. Fertilizers, insecticides, acaricides, herbicides

(weed killers) have and are still playing a good role in agricultural and animal production. In

some ecological zones, in order to get good harvest, fertilizer, herbicide and insecticide

application is necessary. The same case applies to animal production. As regards to control and

prevention of tick-borne diseases, application of different acaricides is often stressed. Also is the

use of different drugs to treat internal parasites such as worms, and vaccines to prevent certain

diseases.

8.The Importance of Chemistry in Daily Life

State the importance of Chemistry in daily life

There are a number of reasons for studying chemistry. If you ask someone to tell you the reason

for studying chemistry, he/she will give reasons based on how the subject touches him/her.

However, there are general and universal reasons as to why we should devote our valuable time

and energy to the study of chemistry. In general, we study chemistry because it helps as to

understand:

 the composition of materials around us;

 the nature, properties and behaviour of these materials;

 why and how materials behave as they do;

 how a new material, based on the known properties of its allies or counterparts might

behave;

 how to make new materials which will be useful to us; and

 how to extract and use materials from the earth to improve our welfare.

In economic and occupational terms, we can say that the knowledge of chemistry helps us:

 to produce professionals in different disciplines such as pharmacy, engineering, medical

and natural science professions; and

 make items, goods and materials for sale such as chemical laboratory equipments and

reagents, medicines, rubber, cement, paints, steel, plastics, etc. What other materials do you think

can be included in the list?

Therefore, we can summarize that the study of chemistry is important for survival, development

and welfare of man as well as sustainable production of crops and animals.

LABORATORY TECHNIQUES AND SAFETY

A laboratory is a room or building specially designed for conducting various scientific

experiments. An appropriate school laboratory has the following features:

 a room with enough space for carrying out scientific experiments;

 a store for keeping laboratory apparatus, chemicals and reagents;

 an office for laboratory technician to sit in and design scientific experiments;

 enough ventilation to let in fresh air and light;

 wide doors and several exits for emergency evacuation in case of an accident; and

 a wide table in front of the laboratory room, fitted with sinks for experiment

demonstrations by the teacher or technician.

Rules and safety precautions in a chemistry laboratory

laboratory Rules

State laboratory rules

Chemistry is best studied through doing experiments. Most experiments are conducted in the

laboratory. It is important to read and follow laboratory rules to avoid causing accidents. Your

teacher will teach and give you more rules. The following are some important laboratory rules:

1. Do not enter the laboratory without permission from your teacher or laboratory

technician.

2. Wear safety goggles all the time while in the laboratory. Obey this rule whether you are

actually working on an experiment or simply writing in your laboratory notebook.

3. Contact lenses are not allowed. Even when worn under safety goggles, various fumes

may accumulate under the lens and cause serious injuries or blindness.

4. Put on closed shoes and trousers when in the laboratory. Sandals and shots are strictly

prohibited.

5. Never walk or run unnecessarily in the laboratory.

6. Tie back long hair when using open flames.

7. Eating, drinking, and smoking are strictly prohibited in the laboratory.

8. Don‟t perform any experiment not authorized by your teacher or lab technician. If you

are curious about trying a procedure not covered in the experimental procedure, consult your

teacher or laboratory technician.

9. Never taste anything. Never directly smell the source of any vapour or gas; instead drift a

small sample to your nose. Do not inhale this vapour directly but take in only enough to detect an

odour if one exists.

10. Always wash your hands after experiments.

11. Never use your hands to transfer chemicals. Use a spatula instead.

12. Notify your teacher or technician immediately in case of an accident

13. Know what chemicals you are using, carefully read the label twice before taking anything

from the reagent bottle. Do not interchange labels.

14. Excess reagents are never to be returned to stock bottles. If you take too much, dispose of

the excess.

15. Many common reagents, for example, alcohol, acetone and carbon disulphide are highly

flammable. Do not use them anywhere near open flames.

16. Pour more concentrated solutions into less concentrated solutions to avoid violent

reactions. For example, always add acid to water; not water to acid. If you pour water into acid

instead, the heat of reaction will cause the water to explode into steam, sometimes violently, and

the acid will splash.

17. If chemicals accidentally splash onto your skin or eyes, flush immediately with plentiful

amounts of water and report to your teacher or lab technician.

18. Never point a test tube or vessel that you are heating at yourself or your colleague.

19. Dispose of chemicals properly. Unless you are told otherwise, assume that only water

may be poured in the laboratory sinks.

20. When an experiment is completed, always clean up your work area and dispose of the

broken glass properly. Return all equipment to its proper storage places.

21. Never take away anything from the laboratory without your teacher‟s permission.

22. Beware of hot glass because it looks exactly the same as a cold glass. Never touch it with

your hand.

23. Always adjust the Bunsen burner to give a luminous flame when not using it (or just

simply turn it off).

24. Use equipment or apparatus only for its designated use.

25. Never eat or drink from laboratory glassware.

26. Make sure all the burners are turned off before leaving the laboratory. Check that the gasNOTE: All the above rules and safety measures are applicable to all research, teaching and
academic laboratories. However, your laboratory may require some more rules that apply to
specific materials and equipment.

First aid and first aid kit
FIRST AID

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First aid is the help given to someone who is injured or sick before the victim gets further
medical assistance. This help can be given by any person regardless of his/her knowledge in a
medical profession.
Whenever an accident occurs, something must be done immediately to help and save life of the
victim. You must always be ready to give a hand to a victim whenever an accident occurs close
to you. To give aid effectively and successfully, one must have elementary knowledge on how to
assist different victims. If you do not know how to help a certain victim, you can ask someone to
assist instead. Do not engage yourself in assisting if you actually do not know where to start.
You may find yourself worsening the situation of the victim unknowingly. However, this should
not be taken as an excuse for failing to help. Always be ready to render some kind of help. First
aid helps to:
1. relieve pain and bring hope to the victim.
2. prevent permanent disability
3. prevent the victim‟s condition from getting worse
4. reduce the possibility of death.
5. shorten recovery time
Possible Causes of Accidents in a Chemistry Laboratory
Identify possible causes of accidents in a chemistry laboratory
Accidents may occur in a school laboratory if utmost care is not taken into account. Accidents in
the laboratory are mainly cuts on parts of the body such as hands, fingers, legs or head. Others
are burns from flames, scalds from boiling fluids, bruises and grazes due to accidental falling on
a slippery floor.
Some possible causes of accidents in the laboratory include:
 Failure to follow the correct experimental procedures for example, pouring water into an
acid instead of pouring an acid into water as the rule is.
 Neglecting some laboratories rules such as ignoring to wear protective gears, tasting the
chemicals, eating or drinking while in the laboratory, etc.

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 Failure to adhere to proper conduct in the laboratory like running unnecessarily and
conducting experiments without your teacher's or technician's permission and guidance.
 Improper use or handling of laboratory equipment and apparatus when conducting
experiments, which could lead to breakage and in turn cause cuts, bruises, grazes, etc.
 A slippery laboratory floor which can cause fractures, cuts, bruises, grazes, etc
 Accidental spillage of chemicals on body parts such as hands, face, eyes, etc, could lead
to burns and damage.
 Poor ventilation in the laboratory may cause suffocation (due to inadequate oxygen
supply) and poisoning (by inhaling poisonous gases produced when experimenting).
 Improper disposal of chemical wastes may result in explosions, burns or even fires.
 The leaking of gases from taps or cylinders may cause fires or even explosions.
 Use of wrong reagents due to incorrect labeling of chemicals or use of reagents or
chemicals that have expired may cause burns, poisoning or damage to apparatus or equipment.
 Inadequate prior information or knowledge on procedures and hazards associated with
certain practical activities or reactants may result in burns, poisoning or explosions.
 Loose or improperly plugged electrical appliances may cause electric shock, especially
when touched with wet hands and during fixing of sockets.
In general, it can be concluded that most laboratory accidents are a result of negligence and
carelessness of experimenters. It is also due to failure to follow the laboratory rules and general
safety measures.
The Items Found in a First Aid Kit
Name the items found in a first aid kit
A First Aid Kit is a box in which first aid chemicals, tools and instruments are kept. In the
laboratory, the box is usually kept in a place where it can be easily reached in case of an
accident, preferably on the wall.

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Each student must be familiar with the tools and chemicals kept in the kit and learn how to use
them to provide first aid to a victim.

First aid kit and its contents
How Each First Aid Kit Item is Used
Demonstrate how each first aid kit item is used
The table below shows types of chemicals found in a First Aid Kit and their functions.
Tool/chemical/item Function
First aid manual Contains guidelines on how to use the items in the first aid kit

Sterile gloves

Worn on hands when attending bleeding cuts or wounds to
avoid infecting wounds and to prevent direct contact with the
victim‟s body fluids
Sterile dressing Stops bleeding

Antiseptic agent

Cleaning and disinfection of wounds, cuts, bruises, grazes or
blisters

Soap Washing hands, wounds and equipment
Antibiotic ointment Prevents infection on cuts and bruises in or near the eye

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Burn ointment Applied on burns to prevent infection
Petroleum jelly Soothing broken skin
Plaster or adhesive bandage Covering small wounds or cuts
Sterile gauze Covering wounds to protect them from dirt or germs
Eye wash solution Flushing the eyes or as a general decontaminant
Thermometer Recording body temperature
Antibiotic towelettes or cotton wool Cleaning and drying cuts and wounds
Iodine tincture Dressing fresh cuts and bruises
Pain relieving drugs such as aspirin, paracetamol, panadol, etc Relieving mild pains
Liniment Reducing muscle pain

Mild antibiotics

Treating mild bacterial infections on the skin, ear, nose and
mouth

Gentian violet solution

Applied on minor wounds and treatment of serious heat
wounds
Hydrogen peroxide solution Cleaning wounds
Methylated spirit (70% alcohol) Cleaning cuts and bruises
Bandages Dressing wounds and cuts, and immobilizing injured limbs
Scissors or razor blade Cutting dressing materials
Dental kit Treatment of broken teeth, loss of crown or filling
Safety pins (small and big) Splinter removal and securing triangular bandage slings

19

Tweezers Splinter or stinger removal
Resealable oven bag Container for contaminated articles

Main Difference – Phase of Matter vs State of Matter

Matter is any substance that exists in the universe. Matter has a mass and a volume that occupy the space. Matter can exist in different forms according to the internal and external factors of matter. The same substance can exist in different forms at different temperatures, pressures, etc. The terms phase and state are used to describe these different forms of matter. Both these terms explain the same property of matter, but are different from each other according to several factors as discussed in this article. The main difference between phase of matter and state of matter is that phase of matter explains uniform chemical and physical properties of matter whereas state of matter explains the form of matter at a given temperature and a pressure.

Key Areas Covered

1. What is Phase of Matter
      – Definition, Examples
2. What is State of Matter
      – Definition, Examples3. What are the Similarities Between Phase of Matter and State of Matter
      – Outline of Common Features4. What is the Difference Between Phase of Matter and State of Matter
      – Comparison of Key Differences

Key Terms: Gases, Liquid, Matter, Phase Of Matter, Pressure, Solid, State Of Matter, Temperature

Difference Between Phase of Matter and State of Matter - Comparison Summary

What is Phase of Matter

Phase of matter is the form of matter that has uniform chemical and physical properties. In other words, phase of matter is a region of a substance that has uniform chemical and physical properties inside the boundary.

There are four major phases of matter. They are solid phase, liquid phase, gaseous phase and plasma phase. In these phases of matter, the density, index of refraction, chemical composition, etc. are uniform physical and chemical properties. The difference between these phases mainly depends on the arrangement of particles (these particles can be molecules, atoms or ions).

For a certain substance, the phase can be changed from one phase to a different phase. For example, by changing the temperature of water, liquid water phase can be converted into vapor phase (gaseous phase) of water. This is known as the phase transition.

Main Difference - Phase of Matter vs State of Matter

Figure 1: Phase Diagram for Water

The phase transition can be explained by terms such as melting, freezing, vaporization, sublimation, condensation, etc. The above image shows the phase diagram of water. The letters S, L and V stand for solid phase, liquid phase, and vapor phase respectively. TP indicates the triple point of water. It gives the temperature and pressure in which water can exist in all three phases at the same time as an equilibrium.

What is State of Matter

State of matter is the form of matter at a given temperature and pressure. The state of matter depends on the temperature and pressure. At a given temperature and pressure a substance can exist mainly in one of four major states of matter: solid state, liquid state, gaseous state and plasma state of matter.

Difference Between Phase of Matter and State of Matter

Figure 2: The Three Main States of Matter

It is not essential to have the uniform physical and chemical properties in a substance when considering the state of mater. Therefore, there can be several phases in one state of matter. This happens when these phases are immiscible with each other but are in the same state of matter.

The state of matter can be changed by changing the temperature of a substance since the change in temperature can change the internal energy of a substance. Hence, the kinetic energy of particles in that substance is changed. It causes the state of matter to be changed.

Similarities Between Phase of Matter and State of Matter

Both terms explain the form of matter.
Both types include the same forms of matter: solid, liquid. Gas and plasma.

Difference Between Phase of Matter and State of Matter

Definition

Phase of Matter: Phase of matter is the form of matter that has uniform chemical and physical properties.

State of Matter: State of matter is the form of matter at a given temperature and pressure.

Nature of Properties

Phase of Matter: A phase of matter has uniform properties.

State of Matter: A state of matter may or may not have uniform properties.

Phase

Phase of Matter: A phase of matter has only one phase.

State of Matter: A state of matter can have several phases.

Transition

Phase of Matter: The change in phase does not change the uniformity of matter.

State of Matter: The change in state may or may not change the uniformity of matter.

Conclusion

Both phase of matter and state of matter explain the same concept, i.e., the form of matter. But they are two separate terms when the definitions are considered. The main difference between phase of matter and state of matter can be given as: phase of matter explains uniform chemical and physical properties of matter whereas state of matter explains the form of matter at a given temperature and a pressure.

Main Difference – Element vs Molecule vs Compound

The terms element, molecule, and compound, have different definitions and properties as discussed below in this article. Although often we use the term compound to name any molecule, not all compounds are only molecules. There are many other chemical species that we can call a compound. An element is a substance that cannot be broken down further by chemical means. A molecule is a substance that is made out of two or more atoms bonded via chemical bonds. A compound is a molecule composed of different types of atoms bonded via chemical bonds. Therefore, a compound is also a type of molecule, but they are not the same. The main difference between element, molecule and compound is that an element is a substance that cannot be further divided into parts by chemical means whereas a molecule is a substance that can be further divided into parts by chemical means and a compound is also a type of molecule but is composed of different types of molecules.

Key Areas Covered

1. What is an Element
– Definition, Periodic Table, Reactivity, Isotopes
2. What is a Molecule
– Definition, Chemical Formula, Different Types
3. What is a Compound
– Definition, Different Types
4. What is the Relationship Between Element Molecule and Compound
5. What is the Difference Between Element Molecule and Compound
– Comparison of Key Differences

Key Terms: Atom, Atomic Number, Element, Chemical Bond, Compound, Covalent Bond, Electron Configuration, Ionic Bond, Mass Number, Molecule

Difference Between Element Molecule and Compound - Comparison Summary

What is an Element

A chemical element is a substance that cannot be broken down by chemical means. Many different chemical elements have been discovered so far. They have a unique property, i.e., the number of protons in the nucleus. This is called the atomic number. The atomic number of an element is a fixed value for a certain element. Two elements cannot have the same atomic number. Any change in the atomic number changes the element. However, elements can be changed through nuclear reactions.

Periodic Table

Chemical elements are arranged in the periodic table of elements based on their atomic number and the electron configuration. A chemical element can also be explained as a species of atoms or a group of atoms. This is because the atoms that can be found anywhere belong to a certain chemical element. This happens because of the uniqueness of the atomic number for a certain chemical element.

Difference Between Element Molecule and Compound_Figure 1

Figure 1: Periodic Table of Elements

In the periodic table of elements, there are different categories of chemical elements. Some of the classifications are shown below.

Metals, non-metals, and metalloids
s block elements, p block elements, d block elements and f block elements.
Alkali metals, alkaline earth metals, transition metals.
Halogens, noble gases, etc.

Reactivity

Some chemical elements are inert; some are less reactive while some are very reactive. Inert chemical elements include the group of noble gasses. All other elements can undergo chemical reactions easily. This is because, they do not have incomplete electron shells according to the electron configuration of noble gases, and thus are very stable as individual atoms. They have no reason to react with other elements. But the other chemical elements have incomplete electron configurations. Therefore, they undergo different chemical reactions in order to fill their electron shells. The less reactive chemical elements have a partially filled, yet stable electron configurations.

Main Difference - Element Molecule vs Compound

Figure 2: Metal Activity Series

Isotopes

Some chemical elements are highly radioactive since they are highly unstable. They decay over time until they get a stable state. Some chemical elements have different forms known as isotopes. Isotopes of a certain chemical element have the same atomic number but a different mass number. This means, the number of protons in their nuclei is the same; hence, they belong to the same chemical element. But the number of neutrons in the nuclei are different from each other.

Difference Between Element Molecule and Compound_Figure 3

Figure 3: Isotopes of Hydrogen Chemical Element

There are names and symbols used to name each and every element. Most of these names are Latin words, and the symbols are derived accordingly.

What is a Molecule

A molecule is a group of two or more atoms chemically bonded to each other and is neutral. A molecule may contain the atoms of the same chemical element or different chemical elements. A molecule in chemistry is a polyatomic chemical species with a neutral electrical charge. Molecules can be categorized into different groups depending on the chemical and physical properties of molecules.

A molecule may contain atoms bonded via either covalent bonds or ionic bonds. A covalent bond is formed when two atoms share their unpaired electrons. An ionic bond is an electrostatic attraction between two or more atoms.

Chemical Formula

The composition of atoms in a molecule is given by its chemical formula. The empirical formula gives the ratio between the atoms. For example, C3H6 is the chemical formula of propene. There are three carbon atoms and six hydrogen atoms bonded to each other. The empirical formula for this molecule is CH2.

Difference Between Element Molecule and Compound

Figure 4: Some Common Molecules

Different Types of Molecules

Based on the types of atoms present in a molecule, it can be either homonuclear or heteronuclear. Homonuclear molecules are composed of atoms of the same element. Heteronuclear molecules are composed of atoms of different chemical elements.
Molecules can be either organic or inorganic. Organic molecules are composed of essentially C,H along with some other elements. Inorganic molecules may have different combinations of different chemical elements.
Number of atoms per molecule: diatomic molecules, triatomic molecules, polyatomic molecules.
Molecules composed only of covalent bonding are covalent molecule, and the molecules containing ionic bonding are ionic molecules.
According to geometry, molecules can be either symmetrical or asymmetrical molecule. For example, the linear geometry of CO2 makes it a symmetrical molecule.

Likewise, there are many types of molecules that can be found in nature. They have different abundances. The individual atoms are not molecules. For example, Helium (He) is not a molecule.

What is a Compound

A compound is a chemical species that is formed when two or more atoms join together chemically, with covalent or ionic bonds. All compounds are molecules, but not all molecules are compounds. Homonuclear molecules are not compounds. Only heteronuclear molecules are considered as compounds. Compounds can be grouped in different ways, only a few are mentioned below.

Difference Between Element Molecule and Compound_Figure 5

Figure 5: This is a covalent compound that contains atoms of different chemical elements

Different Types of Compound

Based on the number of atoms, compounds can be diatomic, triatomic or polyatomic.

Based on the type of chemical bonding, covalent compounds contain covalent bonds, and ionic compounds contain ionic bonds.

Based on the complexity, some compounds are simple compounds while other are complex compounds.

Based on the components (cation, anions, ), compounds can be organic compound or inorganic compound. Organic compounds include hydrocarbons, carboxylic acids, amides, ammines, alcohols, etc. Inorganic compounds include oxides, hydrides, halides, nitrites, nitrates, carbonates, etc.

Relationship Between Element Molecule and Compound

Molecules are made out of atoms of same or different chemical elements. Molecules containing different types of elements are called compounds.

Difference Between Element Molecule and Compound

Definition

Element: A chemical element is a substance that cannot be broken down by chemical means.

Molecule: A molecule is a group of two or more atoms chemically bonded to each other.

Compound: A compound is a chemical species that is formed when two or more atoms join together chemically, with covalent or ionic bonds.

Members

Element: There are 115 known chemical elements.

Molecule: Substances composed of two or more atoms chemically bonded to each other are molecules.

Compound: Substances composed of two or more atoms of different chemical elements are compounds.

Unique Properties

Element: Chemical elements contain a unique atomic number.

Molecule: Molecules can be either homonuclear or heteronuclear.

Compound: Heteronuclear molecules are compounds.

Chemical Element

Element: An element contains similar atoms.

Molecule: A molecule can have atoms of either the same element or different elements.

Compound: A compound has atoms of different elements.

Chemical Bonding

Element: Atoms of different elements can form different types of chemical bonds depending on their electron configurations and the stability.

Molecule: Molecules can have either covalent bonds or ionic bonds.

Compound: Compounds can have covalent bonds, ionic bonds or metallic bonds.

Examples

Element: Some examples for chemical elements include oxygen, hydrogen, nitrogen, copper, zinc, etc.

Molecule: Some examples for molecules include oxygen (O2), ozone (O3), water (H2O), etc.

Compound: Some examples for compounds include sodium chloride (NaCl), calcium carbonate (CaCO3), etc.

Conclusion

Molecules are composed of chemical elements. Molecules that contain two or more different chemical elements are known as compounds. The main difference between element molecule and compound is that an element is a substance that cannot be further divided into parts by chemical means whereas a molecule is a substance that can be further divided into parts by chemical means and a compound is also a type of molecule but is composed of different types of molecules.

Main Difference – d vs f Block Elements

A chemical element is any material that cannot be broken down or changed by chemical means. There are 118 known chemical elements. These chemical elements are the building blocks of matter. All chemical elements are arranged in the periodic table of elements, in the order of increasing atomic number. There are also four groups of elements in the periodic table: s block, p block, d block and f block. Elements are grouped into these groups based on their electron configurations. For example, s block elements have their outermost electrons in an s orbital. p block elements have their outermost electrons in a p orbital. The main difference between d block elements and f block elements is that d block elements are chemical elements having electrons filled to their d orbitals whereas f block elements are chemical elements having electrons filled to their f orbitals.

Key Areas Covered

1. What are d Block Elements
– Definition, Chemical Properties
2. What are f Block Elements
– Definition, Chemical Properties, Lanthanides and Actinides
3. What is the Difference Between d and f block Elements
– Comparison of Key Differences

Key Terms: Actinides, Aufbau Principle, d Block, Electron Configuration, f Block, Inner Transition Elements, Lanthanides, Orbitals, Periodic Table

Difference Between d and f Block Elements - Comparison Summary

What are d Block Elements

d block elements are chemical elements having electrons filled to their d orbitals. The very first requirement for an element to be a d block element is the presence of d orbitals. Elements having at least one electron in their d orbitals are categorized as d block elements. The d-block of the periodic table is located between the s-block and the p-block.

One important fact about d block elements is that they have d orbitals that are partially or completely filled with electrons. According to Aufbau principle, electrons fill orbitals according to the ascending order of the energies of orbitals. In other words, electrons fill the ns orbital before filling the (n-1) d orbital. This is because the energy of ns orbital is lower than (n-1) d orbital. In elements of the first row of the periodic table, electrons first fill the 4s orbital before filling the 3d orbital.

Figure 1: Four Major Groups of the Periodic Table

But there are some exceptions as well. Although the energy level is lower, sometimes electrons fill the orbitals with the most stable electron configuration. For example, ns1nd10 configuration is more stable than ns2nd9. That is due to the stability of the complete filling of the d orbitals. Such two examples are shown below.

Chromium (Cr) = [Ar]3d54s1

Copper (Cu) = [Ar]3d104s1

All d block elements are metals. They show very high melting points and boiling points due to their strong metallic bonds. The decreasing of the atomic radii is slight compared to that of s and p block elements. Moreover, the densities are very high due to the metallic nature. Due to the presence of d electrons, d block elements show variable oxidation states.

What are f Block Elements

f block Elements are chemical elements having electrons filled to their f orbitals. The f block is shown in the periodic table as a separate group at the bottom of the periodic table. That is because they have electrons filling up the f orbitals that are shielded by other orbitals; hence, f block elements are known as “inner transition elements”. The true position of the f block in the periodic table is between the s block and d block. These elements are known as rare elements because most of these elements are rarely found on earth.

There are two series of the f block elements named as,

Lanthanide series (elements are known as Lanthanides)
Actinide series (elements are known as Actinides)

These two series are named as such according to the element from which the series starts with. Lanthanide series starts immediately after Lanthanum (La) and actinide series starts with Actinium (Ac). All Lanthanides and Actinides are metals.

Difference Between d and f Block Elements

Figure 2: Lanthanides and Actinides

Lanthanide Series

Lanthanide series contains 14 elements that start immediately after Lanthanum. Therefore, this series contains a total of 15 elements along with Lanthanum. The atomic number of the series is from 57 to 71. They are known as “first inner transition series”. Lanthanides belong to the 4f series since these elements have their electrons filling to the 4f orbitals. But, Lanthanum has a completely empty f subshell; thus, the elements from Cerium (Ce) to Lutetium (Lu) are considered as the lanthanides.

The 4f electrons of these elements are completely shielded by other orbitals and do not take part in any chemical bonding. The Lanthanides are silvery-white metals and are good conductors of heat. The elements having completely or half-filled f orbitals are stable than other elements of the series.

The most stable oxidation state Lanthanides show is +3. Some elements show +2 and +4 oxidation states as well, but they are not stable as +3 oxidation state. Lanthanides are highly reactive and can react with elements such as hydrogen, oxygen, carbon, etc.

Almost all the ions formed by lanthanides are colourless. Lanthanides are electropositive elements. Therefore, they prefer to form molecules with electronegative elements. However, throughout the series, the changes of the chemical and physical properties are very less.

Actinide Series

Actinides are chemical elements that can be found in the actinide series of the f block in the periodic table of elements. All actinides are radioactive elements due to their unstable nature. These elements are composed of very large atoms. Actinides have their valence electrons in the 5f orbital. The actinide series is composed of chemical elements having the atomic numbers 89 to 103.

The most common and abundant actinides on earth are Uranium and Thorium. They are weakly radioactive and release high energy during radioactive decay. The prominent oxidation state among actinides is +3. In addition, actinides show oxidation states such as +4, +5 and +6.

Actinides form basic oxides and hydroxides. They have the ability to form complexes with ligands such as chlorides, sulfates, etc. Most complexes of actinides are colourful. However, due to the radioactivity and heavy metal behaviour, actinides are considered as toxic compounds.

Difference Between d and f Block Elements

Definition

d Block Elements: d block elements are chemical elements having electrons filled to their d orbitals.

f Block Elements: f block elements are chemical elements having electrons filled to their f orbitals.

Other Names

d Block Elements: d block elements are known as “transition elements”.

f Block Elements: f block elements are known as “inner transition elements”.

Oxidation States

d Block Elements: d block elements show a wide range of oxidation states depending on their electron configurations.

f Block Elements: The most stable oxidation state for f block elements is +3, and there can be other oxidation states as well.

Stability

d Block Elements: Almost all the elements in the d block are stable.

f Block Elements: Most f block elements are radioactive.

Groups

d Block Elements: d block elements can be either transition elements or non-transition elements.

f Block Elements: f block elements are in two series as Lanthanides and Actinides.

Electron Configuration

d Block Elements: d block elements have partially or completely filled outermost d orbitals.

f Block Elements: f block elements are unified by having one or more of their outermost electrons in the f orbital.

Conclusion

The periodic table of elements shows the arrangement of all known chemical elements according to their atomic numbers. There are four major groups of chemical elements that have similar chemical and physical properties among the members of each group. The d block and f block are two groups among those four groups. The main difference between d block elements and f block elements is that d block elements are chemical elements having electrons filled to their d orbitals whereas f block elements are chemical elements having electrons filled to their f orbitals.

Main Difference – Burning vs Combustion

Combustion typically refers to the process of burning something. It is an exothermic reaction which releases heat and light as energy forms. Combustion reactions generally take place when a hydrocarbon or a fuel reacts with oxygen. In other words, hydrocarbons are oxidized by molecular oxygen. Combustion reactions can occur as either complete combustions or incomplete combustions. Both methods form byproducts such as carbon dioxide (CO2), carbon monoxide (CO) and water (H2O). Burning is also a type of combustion. The main difference between burning and combustion is that burning essentially cause the creation of a flame whereas combustion may or may not create a flame.

Key Areas Covered

1. What is Burning
      – Definition, Properties, Examples
2. What is Combustion
      – Definition, Properties, Complete and Incomplete Combustion, Examples
3. What are the Similarities Between Burning and Combustion
      – Outline of Common Features
4. What is the Difference Between Burning and Combustion
      – Comparison of Key Differences

Key Terms: Burning, Carbon Dioxide, Carbon Monoxide, Combustion, Complete Combustion, Flame, Incomplete Combustion

What is Burning

Burning refers to setting something on fire. In order to burn something, there should be three things: a flammable material, oxygen, and fire. The major characteristic of burning is the creation of a flame. When a flammable material is burnt, a flame appears. The color of the flame depends on the amount of oxygen present and the type of material that is going to be burnt.

Burning is a type of combustion since a material is oxidized by molecular oxygen and form byproducts such as carbon dioxide (CO2), carbon monoxide (CO), carbon dust or soot (C) and water (H2O). If the combustion reaction that occurs in burning is a complete oxidation, then the flame is blue colored. But if it is an incomplete combustion, the flame would be a yellow-orange colored one.

Difference Between Burning and Combustion

Figure 1: Burning of wood results in a yellow colored flame.

The heat energy produced by burning is comparatively less. This is because some of the energy is released as light energy due to the formation of a flame. Burning causes the formation of smoke. Burning of wood causes the formation of wood smoke. This smoke is composed of tiny particles which are unburnt. Smoke is a result of incomplete combustion.

What is Combustion

Combustion is a chemical reaction that involves the oxidation of a fuel. This is an exothermic reaction, which releases heat and light as energy forms. The combustion occurs in the presence of oxygen. Therefore, molecular oxygen act as the oxidizing agent.

Combustion may occur in two ways: complete combustion or incomplete combustion. Generally, complete combustion is characterized by a blue flame whereas incomplete combustion is characterized by yellow colored flame. However, combustion reactions do not always produce a flame. When a flame is not formed, that combustion yields a high amount of energy. This is because almost all the energy produced from the combustion is turned into heat, not light.

Figure 2: Petrol can undergo combustion without forming a flame. Therefore it is used in vehicle engines.

The complete combustion mainly results in carbon dioxide (CO2) and water (H2O). Incomplete combustion reactions result in carbon monoxide (CO) and water along with snoot. Both flammable substances and inflammable substances can undergo combustion. Inflammable substances such as petrol do not form a flame but are oxidized by oxygen.

Similarities Between Burning and Combustion

Burning is also a type of combustion reaction.
Both burning and combustion give byproducts such as CO2, CO, and H2
Both reactions release heat energy.
Both types involve oxidation of a material by oxygen.

Difference Between Burning and Combustion

Definition

Burning: Burning is setting something on fire.

Combustion: Combustion is a chemical reaction that involves the oxidation of a fuel.

Flame

Burning: Burning always creates a flame.

Combustion: Combustion may or may not create a flame.

Heat Energy

Burning: Burning forms a low amount of heat energy.

Combustion: Combustion forms a high amount of energy.

Light Energy

Burning: Burning always produce light energy.

Combustion: Combustion may or may not form light as an energy form.

Summary – Burning vs Combustion

Burning and combustion are often the same. The main difference between burning and combustion is the formation of a flame. Combustion reactions that form a flame can be grouped as burnings. However, both burning and combustion produce heat energy. The heat energy produced by combustion reactions are mainly used in industrial purposes. Heat energy produced from burning is mainly used to fulfill household needs, such as wood burning for cooking purposes.

Main Difference – Complete Combustion vs Incomplete Combustion

A combustion reaction is a chemical reaction that releases energy by the oxidation of a fuel. The chemical reactions which release energy are called exothermic reactions. Thus, combustion reactions are exothermic. A fuel can be oxidized with an oxidizing agent. The oxidizing agent for most combustion reactions is atmospheric oxygen. The energy that is released from combustion reactions can be either heat or light. Energy is mainly released in the form of heat; light energy is also released as a flame. Combustion can occur in two ways as complete combustion and incomplete combustion. The main difference between complete combustion and incomplete combustion is that in complete combustion, carbon dioxide is the only product that includes carbon whereas, in incomplete combustion, carbon monoxide and carbon dust are formed as products.

Key Areas Formed

1. What is Complete Combustion
      – Definition, Properties, Examples
2. What is Incomplete Combustion
      – Definition, Properties, Examples
3. What are the Similarities Between Complete Combustion and Incomplete Combustion
      – Outline of Common Features
4. What is the Difference Between Complete Combustion and Incomplete Combustion
      – Comparison of Key Differences

Key Terms: Carbon Dioxide, Carbon Monoxide, Combustion, Exothermic Reaction, Flame, Fuel, Oxidation, Oxidizing Agent

Difference Between Complete Combustion and Incomplete Combustion - Comparison Summary

What is Complete Combustion

Complete combustion is the complete oxidation of fuel. This reaction is highly exothermic and produces a high amount of energy and a limited number of products. In fuel burning or combustion, hydrocarbons in the fuel are oxidized by atmospheric oxygen, giving carbon dioxide (CO2) and water (H2O) as products. The complete combustion occurs where there is a sufficient amount of oxygen present. In the presence of oxygen, carbon atoms in hydrocarbons can get oxidized into carbon dioxide and hydrogen is oxidized into water. The general reaction for complete combustion is given below.

Hydrocarbon + Oxygen → Carbon dioxide + Water

For a fuel like ethanol, the complete combustion can be given as,

C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)

The complete combustion reactions result in oxides of carbon, sulfur and other elements present in the fuel. Carbon is oxidized to carbon dioxide whereas sulfur is oxidized into sulfur dioxide. Complete combustion results in less amount of air pollutants. The complete combustion can be generally characterized by a blue flame.

Difference Between Complete Combustion and Incomplete Combustion

Figure 01: A blue flame is created in complete combustion.

Since the atmosphere is composed of only 21% oxygen by volume, a lot of air is needed for complete combustion to take place. Even though the amount of by products that result from complete combustion is low, it still adds unfavourable emissions. For example, carbon dioxide is a greenhouse gas which causes global warming.

What is Incomplete Combustion

Incomplete combustion is a chemical reaction that involves the partial oxidation of a fuel. The incomplete combustion occurs where there is an insufficient amount of oxygen. Here, the fuel is incompletely oxidized. Hence, the incomplete combustion forms a number of byproducts. But the amount of energy released from this combustion is comparatively low. The major products of incomplete combustion include Carbon monoxide (CO), carbon dust (we call it “soot”) and water (H2O). The general formula for incomplete combustion is shown below.

Hydrocarbon + Oxygen → Carbon monoxide + Carbon + Water

The byproducts may vary according to the amount of oxygen that is involved in the combustion. For example, sometimes it yields only carbon monoxide or soot. However, it commonly gives a mixture of carbon monoxide and soot along with water.

For example, incomplete combustion of ethylene can result in carbon and water as byproducts.

C2H4(l) + O2(g) → 2C(s) + 2H2O(g)

Incomplete combustion of ethanol can form carbon monoxide and carbon dust along with water.

C2H5OH(l) + 2O2(g) → 2CO(g) + 3H2O(l)

C2H5OH(l) + O2(g) → C(s) + 3H2O(l)

Main Difference - Complete Combustion vs Incomplete Combustion -

Figure 2: A yellow flame is produced with incomplete combustion.

Incomplete combustion is characterized by a yellow flame. Since the amount of energy released from incomplete combustion is low, it is undesirable. Moreover, carbon monoxide produced by this combustion is an air pollutant and is deadly for the human body. Carbon monoxide can bind with hemoglobin in our blood and limit the oxygen transportation inside the body.

Similarities Between Complete Combustion and Incomplete Combustion

Both complete combustion and incomplete combustion are exothermic.
They produce heat and light as energy forms.
Both reactions give water as a byproduct.
Both combustion types involve the oxidation of a fuel.
These reactions involve the combination of molecular oxygen with fuel.
Both these combustion reactions result in unfavorable gas emissions.
They can form flames while burning.

Difference Between Complete Combustion and Incomplete Combustion

Definition

Complete Combustion: Complete combustion is the complete oxidation of fuel.

Incomplete Combustion: Incomplete combustion is the partial oxidation of fuel.

Energy Released

Complete Combustion: Complete combustion produces a high amount of energy.

Incomplete Combustion: Incomplete combustion produces a low amount of energy.

Amount of Oxygen Involved

Complete Combustion: Complete combustion occurs where there is enough oxygen present.

Incomplete Combustion: Incomplete combustion occurs where there isn’t enough oxygen present.

Byproducts

Complete Combustion: Complete Combustion produces carbon dioxide and water as major byproducts.

Incomplete Combustion: Incomplete combustion produces carbon monoxide, carbon dust and water as major byproducts.

Flame

Complete Combustion: Complete combustion creates a blue colored flame.

Incomplete Combustion: Incomplete combustion creates a yellow colored flame.

Effect on the Environment

Complete Combustion: Complete Combustion produces carbon dioxide which can cause global warming.

Incomplete Combustion: Incomplete combustion produces carbon monoxide which is an air pollutant.

Conclusion

Combustion reactions are exothermic reactions that release energy when fuel is burnt. Complete combustion of a fuel yields a high amount of energy whereas incomplete combustion yields a less amount of energy. This is the main difference between complete combustion and incomplete combustion. Complete combustion is very important in industrial scale applications. Incomplete combustion is used in household needs such as burning wood to make heat energy for cooking, etc. Even though there are a number of uses in combustion, it causes the emission of unfavorable gases to the environment that can act as air pollutants.

Main Difference – Combustion vs Pyrolysis

Combustion and pyrolysis are thermochemical reactions. Combustion is an exothermic chemical reaction; the combustion of a fuel can form light and heat as forms of energy. Pyrolysis is a decomposition reaction; here, organic materials are decomposed when provided with heat. Although both these processes are thermochemical reactions, there are differences between the two processes. The main difference between combustion and pyrolysis is that combustion is done under the presence of oxygen whereas pyrolysis is done under the absence (or near absence) of oxygen.

Key Areas Covered

1. What is Combustion
      – Definition, Complete and Incomplete Combustion, Uses
2. What is Pyrolysis
      – Definition, Process, and Uses
3. What is the Difference Between Combustion and Pyrolysis
      – Comparison of Key Differences

Key Terms: Burning, Combustion, Complete Combustion, Decomposition, Exothermic Reaction, Incomplete Combustion, Pyrolysis, Thermochemical Reactions

What is Combustion

Combustion is a chemical reaction that involves the reaction between substances and oxygen, producing light and heat as forms of energy. This process is also called burning. Heat and light are the energy forms given as the outcome of the reaction. Light energy appears as a flame. However, most of the energy is released as heat energy.

Combustion reaction can be found in two types as complete combustion and incomplete combustion.

Complete Combustion

Complete combustion occurs when an excess of oxygen is present for the reaction. This gives a limited number of products. When fuel is burnt, it gives carbon dioxide and water as the end products. When an element is burnt, it gives the most stable oxide of that element.

Incomplete Combustion

Incomplete combustion occurs in the presence of a low amount of oxygen. This gives more products at the end. When fuels undergo incomplete combustion, it gives carbon monoxide along with carbon dioxide and water. Sometimes, even unburnt carbon element is also produced. Here, carbon is released as soot.

Figure 1: Fire is a Result of Combustion

There are many uses of combustion reaction. One major use is the production of energy by burning fuels. This is important in industries, automobiles, etc. Producing fire is another use. Fire is used for many needs such as cooking. Sometimes, combustion of elements is used to identify elements. Different elements give different colored flames when combusted. By observing these flames, we can identify different elements.

What is Pyrolysis

Pyrolysis is the chemical decomposition of organic materials in the absence of oxygen. This process requires the application of heat. Therefore, the rate of pyrolysis can be increased by increasing the temperature.

Pyrolysis typically occurs at temperatures above 430oC. However, since it is very difficult to obtain an oxygen-free atmosphere for pyrolysis, it is done under conditions with near absence of oxygen. Pyrolysis gives end products in gaseous phase, liquid phase, and solid phase. Most substances are converted into gases. Sometimes a little amount of liquid is formed. This liquid is called tar. The solid residue typically includes charcoal and biochar.

Figure 2: Products of Pyrolysis

The process of pyrolysis transforms organic material into their gaseous components, a solid residue of carbon and ash, and a liquid called pyrolytic oil. In pyrolysis, there are two methods that are used to remove any contaminants from a substance. They are destruction and removal. In destruction, contaminants are broken down into smaller compounds. But in the process of removal, rather than breaking compounds, contaminants are separated.

Pyrolysis is useful in industries for the production of charcoal, activated carbon, methanol, etc. Apart from that, pyrolysis treats and destroys semi-volatile organic compounds, fuels, and pesticides in soil. This process can also be used to treat organic waste coming out from factories.

Difference Between Combustion and Pyrolysis

Definition

Combustion: Combustion is a chemical reaction that involves the reaction between substances and oxygen producing light and heat as forms of energy.

Pyrolysis: Pyrolysis is the chemical decomposition of organic materials in the absence of oxygen.

Atmosphere

Combustion: Combustion is done under the presence of oxygen in the atmosphere.

Pyrolysis: Pyrolysis is done under the absence of oxygen.

End Products

Combustion: Combustion produces gaseous end products.

Pyrolysis: Pyrolysis produces gaseous components along with trace amounts of liquid and solid residues.

Types

Combustion: Combustion may occur as complete combustion or incomplete combustion.

Pyrolysis: Pyrolysis can be done in a vacuum or in an atmosphere with near absence of oxygen.

Conclusion

Combustion and pyrolysis are thermochemical reactions. These reactions are used in industries and daily needs. These processes are different from each other in several factors. However, the main difference between combustion and pyrolysis is that combustion is done under the presence of oxygen whereas pyrolysis is done under absence (or near absence) of oxygen.

Main Difference – Combustion vs Oxidation Reactions of Ethanol

Ethanol is an alcohol having the molecular formula C2H5OH. The chemical formula of ethanol is CH3CH2OH. Ethanol is used as fuel since it can undergo combustion reactions. It can also undergo oxidation reactions to form aldehyde forms and carboxylic acid forms. The main difference between combustion and oxidation reactions of ethanol is that combustion reactions of ethanol always produce heat and light whereas oxidation reactions of ethanol do not always produce heat and light.

Key Areas Covered

1. What are the Combustion Reactions of Ethanol
      – Definition, Properties, Reactions
2. What are the Oxidation Reactions of Ethanol
      – Definition, Properties, Reactions
3. What is the Difference Between Combustion and Oxidation Reactions of Ethanol
      – Comparison of Key Differences

Key Terms: Aldehyde, Biofuel, Carbon Dioxide, Carbon Monoxide, Carboxylic Acid, Combustion Reaction, Complete Combustion, Complete Oxidation, Ethanol, Gasoline, Incomplete Combustion, Incomplete Oxidation, Oxidation Reaction

What are the Combustion Reactions of Ethanol

Combustion reactions of ethanol are the reactions that occur when ethanol is burnt. Ethanol is a highly flammable liquid that can be used as a fuel. Burning of ethanol can produce heat and light as energy. Therefore, combustion of ethanol is an exothermic reaction. When Ethanol is burnt in the presence of molecular oxygen (O2), it forms two final products. They are carbon dioxide (CO2) and water molecules (H2O).

The combustion of ethanol is indicated by a blue colored flame. The combustion of ethanol is a simple process which involves the combination of ethanol and oxygen. The combustion of ethanol can occur in two ways.

Complete Combustion

Incomplete Combustion

Figure 01: The blue flame indicates the complete combustion of ethanol.

The complete combustion results in CO2 and H2O. But incomplete combustion will produce carbon monoxide (CO) or Carbon (C) as a product. Incomplete combustion will take place when there is insufficient oxygen (O2).

Complete Combustion of Ethanol

CH3CH2OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)

Incomplete Combustion of Ethanol

CH3CH2OH(l) + 2O2(g) → 2CO(g) + 3H2O(l)

CH3CH2OH(l) + O2(g) → C(s) + 3H2O(l)

The incomplete combustion often results in a mixture of carbon monoxide (CO) gas and carbon (C) dust.

The heat produced by the combustion of ethanol is used to drive the piston of vehicle engines. Ethanol can also be used as a rocket fuel. In addition, ethanol can be produced as a biofuel from the biomass of plant material. Therefore, ethanol shows environmental friendly properties than fossil fuel.

Ethanol is a good additive for gasoline. The mixing of ethanol with gasoline prevents some emissions of air pollutants. However, when burnt, ethanol produces a flame which releases pollutants.

What are Oxidation Reactions of Ethanol

Oxidation reactions of ethanol are chemical reactions that take place when ethanol is oxidized by oxidizing agents. Oxidation of ethanol produces an aldehyde called Ethanal as the first product. It can undergo further oxidation to form the carboxylic acid form, which is known as Ethanoic acid.

Figure 2: Oxidation of Ethanol

However, oxidation of ethanol can also occur in the presence of a catalyst. This catalyst is used to reduce the activation energy of the oxidation reaction. If the activation energy is high, the reaction will not be initiated. Oxidation can occur in two phases:

Complete Oxidation

Incomplete Oxidation

The complete oxidation of ethanol forms Ethanoic acid as the end product. Incomplete oxidation of ethanol forms Ethanal as the end product. Both oxidations will produce water molecules (H2O) as byproducts.

Complete Oxidation of Ethanol

Ethanol + Oxygen → Ethanal + Water → Ethanoic Acid + Water

CH3CH2OH(l) + [O] → CH3CHO(l) + H2O(l) → CH3COOH(l) + H2O(l)

The complete oxidation of ethanol results in Ethanoic acid at the end of the reaction. But ethanol oxidation first forms Ethanal and then Ethanal is further oxidized into Ethanoic acid.

Incomplete Oxidation of Ethanol

Ethanol + Oxygen → Ethanal     +     Water

CH3CH2OH(l) + [O] → CH3CHO(l)   +   H2O(l)

In the above equation, [O] indicates the atomic oxygen that comes from the oxidizing agent. As an example, let’s consider Sodium dichromate (Na2Cr2O7) was used as the oxidizing agent along with sulphuric acid (H2SO4).

CH3CH2OH(l)    +      Na2Cr2O7(aq)   +   H2SO4(aq) → CH3CHO(l) +   2NaCrO4(aq) +   2H2O(l)

Oxidation of Ethanol needs either a catalyst or an oxidizing agent in order to complete the reaction. However, oxidation of ethanol does not produce heat or light as energy forms. Another way of oxidation of ethanol is through catalysts. Silver catalyst is such a catalyst. Ethanol can be oxidized by passing a mixture of ethanol vapor and air over a silver catalyst at 500oC. This results in Ethanal as the product along with water (H2O).

Difference Between Combustion and Oxidation Reactions of Ethanol

Definition

Combustion Reactions of Ethanol: Combustion reactions of ethanol are the reactions that occur when ethanol is burnt.

Oxidation Reactions of Ethanol: Oxidation reactions of ethanol are chemical reactions that take place when ethanol is oxidized by oxidizing agents.

Oxidizing Agents

Combustion Reactions of Ethanol: Combustion reactions of ethanol do not require oxidizing agents.

Oxidation Reactions of Ethanol: Oxidation reactions of ethanol require the presence of oxidizing agents.

Catalysts

Combustion Reactions of Ethanol: Combustion reactions of ethanol do not need catalysts.

Oxidation Reactions of Ethanol: Oxidation reactions of ethanol can occur in the presence of catalysts.

End Products

Combustion Reactions of Ethanol: The end products of oxidation reactions of ethanol can be CO2, CO, C, and H2O.

Oxidation Reactions of Ethanol: The end products of combustion reactions of ethanol can be either Ethanal or Ethanoic acid along with H2O.

Energy Forms

Combustion Reactions of Ethanol: Combustion reactions of ethanol can produce heat and light.

Oxidation Reactions of Ethanol: Oxidation reactions of ethanol cannot produce heat and light.

Conclusion

Combustion is also an oxidation reaction since the end product of combustion is always an oxidized species. Moreover, combustion involves the combination of oxygen with the starting material. This also indicates that combustion is an oxidation reaction. Although there are similarities between these two phenomena, there are distinct properties that allow us to distinguish the difference between combustion and oxidation reactions of Ethanol.

Main Difference – Pure Substance vs Mixture

We come across a lot of substances such as water, fuel, food, beverages, and medicine during our daily activities. All these substances fall into two major categories. They are either pure substances or mixtures. The main difference between pure substance and mixture lies in their composition. A pure substance contains only one kind of compound. It can be the same molecule or atom. Mixtures are composed of several kinds of compounds. However, it’s important to look at them individually in order to understand the nature of these substances better.

This article explains,

1. What is a Pure Substance?
– Definition, Composition, Properties, Examples

2. What is a Mixture?
– Definition, Composition, Properties, Examples

3. What is the difference between Pure Substance and Mixture?

What is a Pure Substance

As mentioned above, a pure substance is composed of only one kind of substance. This cannot be separated into any other matter physically. The colour, texture, fragrance or taste of all the particles in a pure substance are the same. Elements and molecules are considered to be pure substances. They consist of only one component; hence, their physical and chemical properties are constant. Pure substances are of one phase and do not separate into two or more phases at a given temperature or pressure. They can be gas, liquid or solid.

Examples of pure substances

Gas:

H2 gas – composed only of H2 molecules. During normal pressure and temperature conditions, it exists in the gaseous phase. However, under extreme conditions, it tends to turn into a liquid.

Liquid:

Distilled deionized pure water- When water does not have any ions dissolved or any other substance dispersed, it is a pure substance in liquid form. However, water is often found naturally as a homogeneous mixture, with various other substances dissolved in it. Water is a liquid under normal conditions, but phase transfer happens when temperature and pressure are varied.

Solid:

Pure metals such as Gold, Silver, and Platinum are good examples for pure solid substances. These are often found as solids and can be turned into a molten liquid under high temperatures.

Pure substances have fixed melting points and boiling points, and this is very helpful in chemical synthesis to identify unknown substances. In organic chemistry, a melting point determination is very important to ensure that a certain desired chemical compound is isolated. The melting point of the unknown pure compound can be compared with that of known compounds to identify an unknown compound.

What is a Mixture

Mixtures consist of two or more substances which can be separated by physical or chemical means. The components of a mixture are not chemically bonded, but physical attractions may be present. This is the reason for their easy separation by processes like filtration, distillation, chromatography, extraction and centrifugation. Properties of components of a mixture are retained even after mixing up. Furthermore, when sugar is dissolved in water, we can still taste the sweet taste of sugar in the solution.

The component ratio is not fixed and may vary from mixture to mixture. Therefore properties like melting point and boiling point are not fixed either.

Mixtures are either homogeneous or heterogeneous depending on the uniformity of composition.

Homogeneous Mixtures

The composition is the same throughout the mixture. Particles are arranged in an orderly way. The components are of either atomic level or molecular level. Homogeneous mixtures are of one phase. There is no layer separation.

Heterogeneous Mixtures

Unlike homogeneous mixtures, there is no uniformity in the composition. Components can be of two phases (ex:- suspensions, soil). Furthermore, they can be distinguished by the naked eye. We can see grains of a rice and sand mixture separately and identify each component.

Read More:

Difference Between Homogeneous and Heterogeneous Mixtures

Difference Between Pure Substance and Mixture

Composition

Pure substance: Pure substances are made of only one matter; thus the composition is the same throughout.

Mixture: Mixtures are made up of several substances that are not chemically bonded.

Properties

Pure substance: Chemical and physical properties are constant.

Mixture: Chemical and physical properties may vary. Individual properties of components are retained.

Classification

Pure substance: Pure substances can be categorised as gas, liquid and solid.

Mixture: Mixtures are categorised as homogeneous and heterogeneous.

Examples

Pure substance: Examples include pure water, H2 gas, gold.

Mixture: Examples include sand and sugar, oil and water.

Finally, it can be stated that almost everything on the earth is either a mixture or a pure substance. A mixture can be defined as a collection of two or more pure substances.

Main Difference – Compound vs Mixture

A compound consists of different kind of atoms which are chemically bonded. A mixture is made up of two or more different kinds of substances (atoms, molecules or compounds) physically intermingled. The main difference between Compound and Mixture is that compounds are chemically bonded whereas mixtures are not.

This article explains,

1. What is a Compound?
– Definition, Characteristics, Types of Bonding, Examples

2. What is a Mixture?
– Definition, Characteristics, Examples

3. What is the difference between Compound and Mixture?

What is a Compound – Definition, Characteristics, Types of Bonding, Examples

Compounds are made of elements. A particular compound consists of two or more elements which are chemically bonded. A compound may be entirely different from the elements that they are made up of. For example, Na is a highly reactive metal, and Cl2 is a toxic gas. However, NaCl is a salt which is used for cooking. Another fine example is water which is made up of H2 and O2. Water is a liquid despite both its components being gases.

In certain compounds, the proportions of the content of the atom remain constant and are unique to that particular compound. If the proportion differs, it gives rise to a new compound. This scenario is elaborated by following examples.

Nitrogen and Oxygen give rise to these two compounds.

N2(g) + O2(g) → 2NO(g) Nitric Oxide or Nitrogen Oxide

2NO(g) + O2(g) → 2NO2(g) Nitrous Oxide or Nitrogen Dioxide

Although Nitrogen Oxide and Nitrous Dioxide are composed of the same elements, their compositions are different. Hence, it gives rise to two different compounds.

Compounds are formed when the attractive forces between the member atoms are greater than that of repulsive forces. Compounds are generally made by either covalent or ionic bonding. Energy is either taken in or given out while making compounds by chemical bonding.

Covalent Bonding

Electrons are shared by participating atoms as shown below. These kinds of compounds are called covalent compounds. If the two atoms are similarly attracted towards electrons (similar electronegativity), the compound is non-polar. However, if the electronegativity gap between the two atoms is huge, the compound becomes a polar one. A water molecule is the best example of this phenomena.

Non-polar compounds – Methane, Ammonia, Hexane

Polar Compounds – Water, CF, HF

Ionic Bonding

Electrons are entirely transferred from one atom to the other. Hence, an electronic charge appears on both the atoms involved in the bonding. Compounds born from these bonds are mainly solids with high melting points and can conduct electrical current. Metal and non- metal elements partner up in forming these type of compounds.

Components of a compound cannot be physically separated. They can be only separated by chemical methods or electrolysis.

What is a Mixture – Definition, Characteristics, Types of Bonding

A mixture is a combination of two or more elements and/or compounds. Though these components are present together, neither are they bonded chemically nor do they make new substances. A good example is sand and water mixture where both components are not chemically bonded and can be separated as individual substances by filtration. Other physical means of separation are evaporation, distillation, chromatography, centrifugation and extraction. For these separation methods, physical properties of components in a mixture are considered. Some of these physical properties are density, size and solubility.

Components in compounds retain their individual characteristics. When you taste a salty water solution, you can feel the salty taste on your tongue. That indicates that the salt is able to give out its characteristic taste even when mixed with water. Mixtures do not have their own properties as compounds do.

Mixtures are often homogeneous or heterogeneous.

Homogeneous mixtures – The composition of the mixture is the same throughout.

Ex:- Salt dissolved in water

Heterogeneous mixtures – Composition may vary from point to point in the mixture.

Ex:- Smog

The air we breathe, and the vast blue ocean can be considered as the largest mixtures found on earth. Both are heterogeneous mixtures.

Difference Between Compound and Mixture

Bond

Compounds: Components are chemically bonded.

Ex:- NaCl, H2O

Mixtures: Components are not chemically bonded.

Ex:- Salty Water, Sand and Sugar

Separation

Compounds: Components cannot be physically separated. They can be separated through electrolysis.

Mixtures: Components can be physically separated easily through methods such as filtration, chromatography, centrifugation, dialysis, evaporation, and distillation.

Characteristics

Compounds: Compounds show their own characteristics, not the individual features of components.

Mixtures: Compounds do not show their own characteristics. Individual features of components are displayed.

Ratio

Compounds: Ratio of components is fixed.

Mixtures: Ratio of components may vary.

Boiling Point and Melting Point

Compounds: Boiling point and melting point are constant for a particular compound.

Mixtures: Boiling point and melting point are not constant.

Energy Transfer

Compounds: Energy is given out or in to prepare compounds through chemical bonding.

Mixtures: There is no or little energy transfer.

Main Difference – Compound vs Mixture

A compound consists of different kind of atoms which are chemically bonded. A mixture is made up of two or more different kinds of substances (atoms, molecules or compounds) physically intermingled. The main difference between Compound and Mixture is that compounds are chemically bonded whereas mixtures are not.

This article explains,

1. What is a Compound?
– Definition, Characteristics, Types of Bonding, Examples

2. What is a Mixture?
– Definition, Characteristics, Examples

3. What is the difference between Compound and Mixture?

What is a Compound – Definition, Characteristics, Types of Bonding, Examples

Compounds are made of elements. A particular compound consists of two or more elements which are chemically bonded. A compound may be entirely different from the elements that they are made up of. For example, Na is a highly reactive metal, and Cl2 is a toxic gas. However, NaCl is a salt which is used for cooking. Another fine example is water which is made up of H2 and O2. Water is a liquid despite both its components being gases.

In certain compounds, the proportions of the content of the atom remain constant and are unique to that particular compound. If the proportion differs, it gives rise to a new compound. This scenario is elaborated by following examples.

Nitrogen and Oxygen give rise to these two compounds.

N2(g) + O2(g) → 2NO(g) Nitric Oxide or Nitrogen Oxide

2NO(g) + O2(g) → 2NO2(g) Nitrous Oxide or Nitrogen Dioxide

Although Nitrogen Oxide and Nitrous Dioxide are composed of the same elements, their compositions are different. Hence, it gives rise to two different compounds.

Compounds are formed when the attractive forces between the member atoms are greater than that of repulsive forces. Compounds are generally made by either covalent or ionic bonding. Energy is either taken in or given out while making compounds by chemical bonding.

Covalent Bonding

Electrons are shared by participating atoms as shown below. These kinds of compounds are called covalent compounds. If the two atoms are similarly attracted towards electrons (similar electronegativity), the compound is non-polar. However, if the electronegativity gap between the two atoms is huge, the compound becomes a polar one. A water molecule is the best example of this phenomena.

Non-polar compounds – Methane, Ammonia, Hexane

Polar Compounds – Water, CF, HF

Ionic Bonding

Electrons are entirely transferred from one atom to the other. Hence, an electronic charge appears on both the atoms involved in the bonding. Compounds born from these bonds are mainly solids with high melting points and can conduct electrical current. Metal and non- metal elements partner up in forming these type of compounds.

Components of a compound cannot be physically separated. They can be only separated by chemical methods or electrolysis.

What is a Mixture – Definition, Characteristics, Types of Bonding

A mixture is a combination of two or more elements and/or compounds. Though these components are present together, neither are they bonded chemically nor do they make new substances. A good example is sand and water mixture where both components are not chemically bonded and can be separated as individual substances by filtration. Other physical means of separation are evaporation, distillation, chromatography, centrifugation and extraction. For these separation methods, physical properties of components in a mixture are considered. Some of these physical properties are density, size and solubility.

Components in compounds retain their individual characteristics. When you taste a salty water solution, you can feel the salty taste on your tongue. That indicates that the salt is able to give out its characteristic taste even when mixed with water. Mixtures do not have their own properties as compounds do.

Mixtures are often homogeneous or heterogeneous.

Homogeneous mixtures – The composition of the mixture is the same throughout.

Ex:- Salt dissolved in water

Heterogeneous mixtures – Composition may vary from point to point in the mixture.

Ex:- Smog

The air we breathe, and the vast blue ocean can be considered as the largest mixtures found on earth. Both are heterogeneous mixtures.

Difference Between Compound and Mixture

Bond

Compounds: Components are chemically bonded.

Ex:- NaCl, H2O

Mixtures: Components are not chemically bonded.

Ex:- Salty Water, Sand and Sugar

Separation

Compounds: Components cannot be physically separated. They can be separated through electrolysis.

Mixtures: Components can be physically separated easily through methods such as filtration, chromatography, centrifugation, dialysis, evaporation, and distillation.

Characteristics

Compounds: Compounds show their own characteristics, not the individual features of components.

Mixtures: Compounds do not show their own characteristics. Individual features of components are displayed.

Ratio

Compounds: Ratio of components is fixed.

Mixtures: Ratio of components may vary.

Boiling Point and Melting Point

Compounds: Boiling point and melting point are constant for a particular compound.

Mixtures: Boiling point and melting point are not constant.

Energy Transfer

Compounds: Energy is given out or in to prepare compounds through chemical bonding.

Mixtures: There is no or little energy transfer.

What is the Difference Between Gas and Liquid Chromatography

October 21, 2019

by Lakna

6 min read

The main difference between gas and liquid chromatography is that the mobile phase of gas chromatography is a gas, which is most often helium, whereas the mobile phase of liquid chromatography is a liquid, which can be either polar or non-polar. Furthermore, the stationary phase of gas chromatography is often a liquid silicone-based material while the stationary phase of liquid chromatography is mainly silica. Moreover, gas chromatography is carried out in a column while liquid chromatography is either carried out in a column or a plane.

Gas and liquid chromatography are the two types of chromatography techniques classified based on the physical state of the mobile phase. Generally, the mobile phase is the phase that flows through the stationary phase.

Key Areas Covered

1. What is Gas Chromatography
– Definition, Principle, Importance
2. What is Liquid Chromatography
– Definition, Principle, Importance
3. What are the Similarities Between Gas and Liquid Chromatography
– Outline of Common Features
4. What is the Difference Between Gas and Liquid Chromatography
– Comparison of Key Differences

Key Terms

Column Chromatography, Gas Chromatography, Liquid Chromatography, Mobile Phase, Stationary Phase

What is Gas Chromatography

Gas chromatography is the type of analytical chromatography whose mobile phase is a gas. Generally, this carrier gas is either an inert gas such as helium or a non-reactive gas such as nitrogen. However, hydrogen is preferred over helium for better separation, although helium is the common carrier gas in 90% of the instruments. Moreover, the stationary phase of gas chromatography is a liquid. Therefore, the full name for gas chromatography is gas-liquid chromatography. Here, a microscopic layer of liquid stationary phase occurs on inert solid support inside a tiny glass tube. Thus, gas chromatography operates as a column chromatography technique.

Figure 1: Gas Chromatography

Furthermore, gas chromatography is responsible for analyzing compounds in the form of vapor. Also, its separation of compounds depends on the partition equilibrium of components between the mobile and the stationary phase. However, the usage of high temperature in gas chromatography makes it unsuitable for separating polymers of high molecular weights. Basically, this is due to the inability of these polymers to become a vapor. In preparative chromatography, gas chromatography is an important tool to prepare pure components from a mixture.

What is Liquid Chromatography

Liquid chromatography is the other type of chromatography classified based on the physical state of the mobile phase. Significantly, its mobile phase is a liquid. For instance, the stationary phase of the liquid chromatography is solid. Therefore, the basic chromatography structure can be either a column or plane chromatography. Generally, in column chromatography, the stationary bed occurs within a tube. In contrast, in planar chromatography, the stationary phase occurs on a plane.

Figure 2: Liquid Chromatography

Moreover, present-day liquid chromatography is mainly the high-performance liquid chromatography (HPLC), which uses a very small packing of articles. Also, HLC operates under high pressure. Therefore, the stationary phase is mainly a porous membrane or a porous monolithic layer, composed of spherical or irregular shaped particles. Meanwhile, the liquid mobile phase flows on the stationary phase under high pressure. However, there are two types of HPLC techniques according to the polarity of the mobile and stationary phases. They are the normal phase and reverse-phase liquid chromatography. Typically, in the normal phase liquid chromatography, the mobile phase is non-polar (e.g. toluene) while the stationary phase is polar (e.g. silica). On the other hand, in reverse-phase liquid chromatography, the mobile phase is polar (e.g. water-methanol mixture) while the stationary phase is non-polar (e.g. C18). However, both types of HPLC operate under room temperature.

Similarities Between Gas and Liquid Chromatography

Gas and liquid chromatography are the two types of chromatography techniques classified according to the type of mobile phase.

Both are laboratory techniques for the separation of a mixture. Also, both are analytical separation methods.

Generally, the mixture to be separated is dissolved in the mobile phase, which carries it through the stationary phase.

However, the separation occurs depending on the properties of the components of the mixture, determining the variable interactions towards the mobile or stationary phase.

Both can be column chromatography.

Mass spectrometry (MS) is the most powerful detection method for both types of chromatography.

Difference Between Gas and Liquid Chromatography

Definition

Gas chromatography refers to the chromatography technique which separates and analyzes volatile compounds in the gas phase while liquid chromatography refers to the chromatography technique useful for separating ions or molecules dissolved in a solvent.

Also Known as

Another name for gas chromatography is gas-liquid chromatography while another name for liquid chromatography is liquid-solid chromatography.

Type of Mobile Phase

The mobile phase of gas chromatography is a gas while the mobile phase of liquid chromatography is a liquid.

Examples

The mobile phase of gas chromatography is most often helium, while the mobile phase of liquid chromatography can be either polar or non-polar.

Mobile Phase Gradient

While the mobile phase has no gradient in gas chromatography, the mobile phase has a gradient in liquid chromatography.

Stationary Phase

Moreover, the stationary phase of gas chromatography is often a liquid silicone-based material while the stationary phase of liquid chromatography is mainly silica.

Chromatographic Bed Shape

Gas chromatography is carried out in a column while liquid chromatography is either carried out in a column or a plane.

Columns

Long and narrow packed or capillary columns are used in gas chromatography while short and wide packed columns are used in liquid chromatography.

Sample

Components of the sample are volatile in gas chromatography, while the components of the sample are less volatile.

Chromatographic Conditions

Gas chromatography operates under high temperatures while liquid chromatography operates under high pressure.

Resolution

The resolution of gas chromatography depends on the volatility of the components of the mixture while the resolution of liquid chromatography depends on the polarity of molecules and the composition of the mobile phase.

Detectors

The two main types of detectors used in gas chromatography are flame ionization detector (FID) and thermal conductivity detector (TCD) while the two main types of detectors used in liquid chromatography are ultraviolet-visible (UV/Vis) spectroscopic detector and refractive index detector (RID).

Importance

Gas chromatography is mainly used in analytical chemistry while high-performance liquid chromatography is the mainly used form of liquid chromatography.

Relative Cost

Also, gas chromatography is a low-cost technique, while liquid chromatography is a high-cost technique.

Applications

Gas chromatography is used for the separation of oils, plant pigments, pesticides, fatty acids, toxins, air samples, drug abuse testing, etc. while liquid chromatography is used for inorganic ions, polymers, sugars, nucleotides, vitamins, peptides, proteins, lipids, tetracyclines, etc.

Conclusion

Gas chromatography is the type of chromatography, using a gas mobile phase. Generally, the mobile phase is helium. Also, the stationary phase of gas chromatography is a liquid with a silicone base. Therefore, it is a type of column chromatography. Liquid chromatography is another type of chromatography, using a liquid mobile phase, which is mainly silica. Moreover, liquid chromatography can be either column or plane chromatography. Hence, the main difference between gas and liquid chromatography is the physical state of the mobile phase.

What is the Difference Between Gas and Liquid Chromatography

October 21, 2019

by Lakna

6 min read

The main difference between gas and liquid chromatography is that the mobile phase of gas chromatography is a gas, which is most often helium, whereas the mobile phase of liquid chromatography is a liquid, which can be either polar or non-polar. Furthermore, the stationary phase of gas chromatography is often a liquid silicone-based material while the stationary phase of liquid chromatography is mainly silica. Moreover, gas chromatography is carried out in a column while liquid chromatography is either carried out in a column or a plane.

Gas and liquid chromatography are the two types of chromatography techniques classified based on the physical state of the mobile phase. Generally, the mobile phase is the phase that flows through the stationary phase.

Key Areas Covered

1. What is Gas Chromatography
– Definition, Principle, Importance
2. What is Liquid Chromatography
– Definition, Principle, Importance
3. What are the Similarities Between Gas and Liquid Chromatography
– Outline of Common Features
4. What is the Difference Between Gas and Liquid Chromatography
– Comparison of Key Differences

Key Terms

Column Chromatography, Gas Chromatography, Liquid Chromatography, Mobile Phase, Stationary Phase

What is Gas Chromatography

Gas chromatography is the type of analytical chromatography whose mobile phase is a gas. Generally, this carrier gas is either an inert gas such as helium or a non-reactive gas such as nitrogen. However, hydrogen is preferred over helium for better separation, although helium is the common carrier gas in 90% of the instruments. Moreover, the stationary phase of gas chromatography is a liquid. Therefore, the full name for gas chromatography is gas-liquid chromatography. Here, a microscopic layer of liquid stationary phase occurs on inert solid support inside a tiny glass tube. Thus, gas chromatography operates as a column chromatography technique.

Figure 1: Gas Chromatography

Furthermore, gas chromatography is responsible for analyzing compounds in the form of vapor. Also, its separation of compounds depends on the partition equilibrium of components between the mobile and the stationary phase. However, the usage of high temperature in gas chromatography makes it unsuitable for separating polymers of high molecular weights. Basically, this is due to the inability of these polymers to become a vapor. In preparative chromatography, gas chromatography is an important tool to prepare pure components from a mixture.

What is Liquid Chromatography

Liquid chromatography is the other type of chromatography classified based on the physical state of the mobile phase. Significantly, its mobile phase is a liquid. For instance, the stationary phase of the liquid chromatography is solid. Therefore, the basic chromatography structure can be either a column or plane chromatography. Generally, in column chromatography, the stationary bed occurs within a tube. In contrast, in planar chromatography, the stationary phase occurs on a plane.

Figure 2: Liquid Chromatography

Moreover, present-day liquid chromatography is mainly the high-performance liquid chromatography (HPLC), which uses a very small packing of articles. Also, HLC operates under high pressure. Therefore, the stationary phase is mainly a porous membrane or a porous monolithic layer, composed of spherical or irregular shaped particles. Meanwhile, the liquid mobile phase flows on the stationary phase under high pressure. However, there are two types of HPLC techniques according to the polarity of the mobile and stationary phases. They are the normal phase and reverse-phase liquid chromatography. Typically, in the normal phase liquid chromatography, the mobile phase is non-polar (e.g. toluene) while the stationary phase is polar (e.g. silica). On the other hand, in reverse-phase liquid chromatography, the mobile phase is polar (e.g. water-methanol mixture) while the stationary phase is non-polar (e.g. C18). However, both types of HPLC operate under room temperature.

Similarities Between Gas and Liquid Chromatography

Gas and liquid chromatography are the two types of chromatography techniques classified according to the type of mobile phase.

Both are laboratory techniques for the separation of a mixture. Also, both are analytical separation methods.

Generally, the mixture to be separated is dissolved in the mobile phase, which carries it through the stationary phase.

However, the separation occurs depending on the properties of the components of the mixture, determining the variable interactions towards the mobile or stationary phase.

Both can be column chromatography.

Mass spectrometry (MS) is the most powerful detection method for both types of chromatography.

Difference Between Gas and Liquid Chromatography

Definition

Gas chromatography refers to the chromatography technique which separates and analyzes volatile compounds in the gas phase while liquid chromatography refers to the chromatography technique useful for separating ions or molecules dissolved in a solvent.

Also Known as

Another name for gas chromatography is gas-liquid chromatography while another name for liquid chromatography is liquid-solid chromatography.

Type of Mobile Phase

The mobile phase of gas chromatography is a gas while the mobile phase of liquid chromatography is a liquid.

Examples

The mobile phase of gas chromatography is most often helium, while the mobile phase of liquid chromatography can be either polar or non-polar.

Mobile Phase Gradient

While the mobile phase has no gradient in gas chromatography, the mobile phase has a gradient in liquid chromatography.

Stationary Phase

Moreover, the stationary phase of gas chromatography is often a liquid silicone-based material while the stationary phase of liquid chromatography is mainly silica.

Chromatographic Bed Shape

Gas chromatography is carried out in a column while liquid chromatography is either carried out in a column or a plane.

Columns

Long and narrow packed or capillary columns are used in gas chromatography while short and wide packed columns are used in liquid chromatography.

Sample

Components of the sample are volatile in gas chromatography, while the components of the sample are less volatile.

Chromatographic Conditions

Gas chromatography operates under high temperatures while liquid chromatography operates under high pressure.

Resolution

The resolution of gas chromatography depends on the volatility of the components of the mixture while the resolution of liquid chromatography depends on the polarity of molecules and the composition of the mobile phase.

Detectors

The two main types of detectors used in gas chromatography are flame ionization detector (FID) and thermal conductivity detector (TCD) while the two main types of detectors used in liquid chromatography are ultraviolet-visible (UV/Vis) spectroscopic detector and refractive index detector (RID).

Importance

Gas chromatography is mainly used in analytical chemistry while high-performance liquid chromatography is the mainly used form of liquid chromatography.

Relative Cost

Also, gas chromatography is a low-cost technique, while liquid chromatography is a high-cost technique.

Applications

Gas chromatography is used for the separation of oils, plant pigments, pesticides, fatty acids, toxins, air samples, drug abuse testing, etc. while liquid chromatography is used for inorganic ions, polymers, sugars, nucleotides, vitamins, peptides, proteins, lipids, tetracyclines, etc.

Conclusion

Gas chromatography is the type of chromatography, using a gas mobile phase. Generally, the mobile phase is helium. Also, the stationary phase of gas chromatography is a liquid with a silicone base. Therefore, it is a type of column chromatography. Liquid chromatography is another type of chromatography, using a liquid mobile phase, which is mainly silica. Moreover, liquid chromatography can be either column or plane chromatography. Hence, the main difference between gas and liquid chromatography is the physical state of the mobile phase.

What is the Difference Between Gas and Liquid Chromatography

October 21, 2019

by Lakna

6 min read

The main difference between gas and liquid chromatography is that the mobile phase of gas chromatography is a gas, which is most often helium, whereas the mobile phase of liquid chromatography is a liquid, which can be either polar or non-polar. Furthermore, the stationary phase of gas chromatography is often a liquid silicone-based material while the stationary phase of liquid chromatography is mainly silica. Moreover, gas chromatography is carried out in a column while liquid chromatography is either carried out in a column or a plane.

Gas and liquid chromatography are the two types of chromatography techniques classified based on the physical state of the mobile phase. Generally, the mobile phase is the phase that flows through the stationary phase.

Key Areas Covered

1. What is Gas Chromatography
– Definition, Principle, Importance
2. What is Liquid Chromatography
– Definition, Principle, Importance
3. What are the Similarities Between Gas and Liquid Chromatography
– Outline of Common Features
4. What is the Difference Between Gas and Liquid Chromatography
– Comparison of Key Differences

Key Terms

Column Chromatography, Gas Chromatography, Liquid Chromatography, Mobile Phase, Stationary Phase

What is Gas Chromatography

Gas chromatography is the type of analytical chromatography whose mobile phase is a gas. Generally, this carrier gas is either an inert gas such as helium or a non-reactive gas such as nitrogen. However, hydrogen is preferred over helium for better separation, although helium is the common carrier gas in 90% of the instruments. Moreover, the stationary phase of gas chromatography is a liquid. Therefore, the full name for gas chromatography is gas-liquid chromatography. Here, a microscopic layer of liquid stationary phase occurs on inert solid support inside a tiny glass tube. Thus, gas chromatography operates as a column chromatography technique.

Figure 1: Gas Chromatography

Furthermore, gas chromatography is responsible for analyzing compounds in the form of vapor. Also, its separation of compounds depends on the partition equilibrium of components between the mobile and the stationary phase. However, the usage of high temperature in gas chromatography makes it unsuitable for separating polymers of high molecular weights. Basically, this is due to the inability of these polymers to become a vapor. In preparative chromatography, gas chromatography is an important tool to prepare pure components from a mixture.

What is Liquid Chromatography

Liquid chromatography is the other type of chromatography classified based on the physical state of the mobile phase. Significantly, its mobile phase is a liquid. For instance, the stationary phase of the liquid chromatography is solid. Therefore, the basic chromatography structure can be either a column or plane chromatography. Generally, in column chromatography, the stationary bed occurs within a tube. In contrast, in planar chromatography, the stationary phase occurs on a plane.

Figure 2: Liquid Chromatography

Moreover, present-day liquid chromatography is mainly the high-performance liquid chromatography (HPLC), which uses a very small packing of articles. Also, HLC operates under high pressure. Therefore, the stationary phase is mainly a porous membrane or a porous monolithic layer, composed of spherical or irregular shaped particles. Meanwhile, the liquid mobile phase flows on the stationary phase under high pressure. However, there are two types of HPLC techniques according to the polarity of the mobile and stationary phases. They are the normal phase and reverse-phase liquid chromatography. Typically, in the normal phase liquid chromatography, the mobile phase is non-polar (e.g. toluene) while the stationary phase is polar (e.g. silica). On the other hand, in reverse-phase liquid chromatography, the mobile phase is polar (e.g. water-methanol mixture) while the stationary phase is non-polar (e.g. C18). However, both types of HPLC operate under room temperature.

Similarities Between Gas and Liquid Chromatography

Gas and liquid chromatography are the two types of chromatography techniques classified according to the type of mobile phase.

Both are laboratory techniques for the separation of a mixture. Also, both are analytical separation methods.

Generally, the mixture to be separated is dissolved in the mobile phase, which carries it through the stationary phase.

However, the separation occurs depending on the properties of the components of the mixture, determining the variable interactions towards the mobile or stationary phase.

Both can be column chromatography.

Mass spectrometry (MS) is the most powerful detection method for both types of chromatography.

Difference Between Gas and Liquid Chromatography

Definition

Gas chromatography refers to the chromatography technique which separates and analyzes volatile compounds in the gas phase while liquid chromatography refers to the chromatography technique useful for separating ions or molecules dissolved in a solvent.

Also Known as

Another name for gas chromatography is gas-liquid chromatography while another name for liquid chromatography is liquid-solid chromatography.

Type of Mobile Phase

The mobile phase of gas chromatography is a gas while the mobile phase of liquid chromatography is a liquid.

Examples

The mobile phase of gas chromatography is most often helium, while the mobile phase of liquid chromatography can be either polar or non-polar.

Mobile Phase Gradient

While the mobile phase has no gradient in gas chromatography, the mobile phase has a gradient in liquid chromatography.

Stationary Phase

Moreover, the stationary phase of gas chromatography is often a liquid silicone-based material while the stationary phase of liquid chromatography is mainly silica.

Chromatographic Bed Shape

Gas chromatography is carried out in a column while liquid chromatography is either carried out in a column or a plane.

Columns

Long and narrow packed or capillary columns are used in gas chromatography while short and wide packed columns are used in liquid chromatography.

Sample

Components of the sample are volatile in gas chromatography, while the components of the sample are less volatile.

Chromatographic Conditions

Gas chromatography operates under high temperatures while liquid chromatography operates under high pressure.

Resolution

The resolution of gas chromatography depends on the volatility of the components of the mixture while the resolution of liquid chromatography depends on the polarity of molecules and the composition of the mobile phase.

Detectors

The two main types of detectors used in gas chromatography are flame ionization detector (FID) and thermal conductivity detector (TCD) while the two main types of detectors used in liquid chromatography are ultraviolet-visible (UV/Vis) spectroscopic detector and refractive index detector (RID).

Importance

Gas chromatography is mainly used in analytical chemistry while high-performance liquid chromatography is the mainly used form of liquid chromatography.

Relative Cost

Also, gas chromatography is a low-cost technique, while liquid chromatography is a high-cost technique.

Applications

Gas chromatography is used for the separation of oils, plant pigments, pesticides, fatty acids, toxins, air samples, drug abuse testing, etc. while liquid chromatography is used for inorganic ions, polymers, sugars, nucleotides, vitamins, peptides, proteins, lipids, tetracyclines, etc.

Conclusion

Gas chromatography is the type of chromatography, using a gas mobile phase. Generally, the mobile phase is helium. Also, the stationary phase of gas chromatography is a liquid with a silicone base. Therefore, it is a type of column chromatography. Liquid chromatography is another type of chromatography, using a liquid mobile phase, which is mainly silica. Moreover, liquid chromatography can be either column or plane chromatography. Hence, the main difference between gas and liquid chromatography is the physical state of the mobile phase.

Wednesday, October 23, 2019

CHEMISTRY NOTES FORM ONE

Created by Boniventure Yohana Salumu

FORM ONE CHEMISTRY NOTES

Main Difference – Phase of Matter vs State of Matter

Key Areas Covered

What is Phase of Matter

What is State of Matter

Similarities Between Phase of Matter and State of Matter

Difference Between Phase of Matter and State of Matter

Definition

Nature of Properties

Phase

Transition

Conclusion

Main Difference – Element vs Molecule vs Compound

Key Areas Covered

What is an Element

Periodic Table

Reactivity

Isotopes

What is a Molecule

Chemical Formula

Different Types of Molecules

What is a Compound

Different Types of Compound

Relationship Between Element Molecule and Compound

Difference Between Element Molecule and Compound

Definition

Members

Unique Properties

Chemical Element

Chemical Bonding

Examples

Conclusion

Main Difference – d vs f Block Elements

Key Areas Covered

What are d Block Elements

What are f Block Elements

Lanthanide Series

Actinide Series

Difference Between d and f Block Elements

Definition

Other Names

Oxidation States

Stability

Groups

Electron Configuration

Conclusion

Main Difference – Burning vs Combustion

Key Areas Covered

What is Burning

What is Combustion

Similarities Between Burning and Combustion

Difference Between Burning and Combustion

Definition

Flame

Heat Energy

Light Energy

Summary – Burning vs Combustion

Main Difference – Complete Combustion vs Incomplete Combustion

Key Areas Formed

What is Complete Combustion

What is Incomplete Combustion

Similarities Between Complete Combustion and Incomplete Combustion

Difference Between Complete Combustion and Incomplete Combustion

Definition

Energy Released

Amount of Oxygen Involved

Byproducts

Flame

Effect on the Environment

Conclusion

Main Difference – Combustion vs Pyrolysis

Key Areas Covered

What is Combustion

Complete Combustion

Complete combustion occurs when an excess of oxygen is present for the reaction. This gives a limited number of products. When fuel is burnt, it gives carbon dioxide and water as the end products. When an element is burnt, it gives the most stable oxide of that element.

Incomplete Combustion

What is Pyrolysis

Combustion: Combustion is a chemical reaction that involves the reaction between substances and oxygen producing light and heat as forms of energy.

Pyrolysis: Pyrolysis is the chemical decomposition of organic materials in the absence of oxygen.

Combustion: Combustion is done under the presence of oxygen in the atmosphere.

Pyrolysis: Pyrolysis is done under the absence of oxygen.

Combustion: Combustion produces gaseous end products.

Pyrolysis: Pyrolysis produces gaseous components along with trace amounts of liquid and solid residues.

Combustion: Combustion may occur as complete combustion or incomplete combustion.

Pyrolysis: Pyrolysis can be done in a vacuum or in an atmosphere with near absence of oxygen.

Combustion Reactions of Ethanol: Combustion reactions of ethanol are the reactions that occur when ethanol is burnt.

Oxidation Reactions of Ethanol: Oxidation reactions of ethanol are chemical reactions that take place when ethanol is oxidized by oxidizing agents.

Combustion Reactions of Ethanol: Combustion reactions of ethanol do not require oxidizing agents.

Oxidation Reactions of Ethanol: Oxidation reactions of ethanol require the presence of oxidizing agents.

Combustion Reactions of Ethanol: Combustion reactions of ethanol do not need catalysts.

Oxidation Reactions of Ethanol: Oxidation reactions of ethanol can occur in the presence of catalysts.

Combustion Reactions of Ethanol: The end products of oxidation reactions of ethanol can be CO2, CO, C, and H2O.

Oxidation Reactions of Ethanol: The end products of combustion reactions of ethanol can be either Ethanal or Ethanoic acid along with H2O.

Combustion Reactions of Ethanol: Combustion reactions of ethanol can produce heat and light.

Oxidation Reactions of Ethanol: Oxidation reactions of ethanol cannot produce heat and light.

Unlike homogeneous mixtures, there is no uniformity in the composition. Components can be of two phases (ex:- suspensions, soil). Furthermore, they can be distinguished by the naked eye. We can see grains of a rice and sand mixture separately and identify each component.

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Pure substance: Pure substances are made of only one matter; thus the composition is the same throughout.

Mixture: Mixtures are made up of several substances that are not chemically bonded.