TOPIC 1: INTRODUCTION TO CHEMISTRY
Introduction To Chemistry
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
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
Materials Objects Made by Application of Chemistry
Mention materials objects made by application of 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?
therefore, means that chemistry is applied in factories, homes,
hospitals, pharmacies, research centers, higher learning institutions,
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
||Drugs, vaccines, nutritional supplements
||Agro-chemicals ( fertilizers, pesticides, herbicides, acaricides), animal drugs and vaccines, animal feed and supplements
||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
||Fuels, lubricants, oil, grease, tar, coolants, tyres
||Clothes, dyes, bleaches, wax, threads
||Shoes, handbags, belts, leather articles
TOPIC 2: LABORATORY TECHNIQUES AND SAFETY
laboratory is a room or building specially designed for conducting
various scientific experiments. An appropriate school laboratory has the
- 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.
State laboratory rules
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.
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.
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
- 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
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.
common reagents, for example, alcohol, acetone and carbon disulphide
are highly flammable. Do not use them anywhere near open flames.
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
- 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.
an experiment is completed, always clean up your work area and dispose
of the broken glass properly. Return all equipment to its proper storage
- 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.
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.
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
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:
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
- All chemicals that react with each other must be stored separately.
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.
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).
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.
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.
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.
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.
for holding or storing chemicals must be inspected for leakages or
other damages. They should have tight stoppers or covers.
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.
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.
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.