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 Chemistry is the science that deals with the composition, structure, and properties 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. Since Chemistry is a science that involve experiments and practical work, chemists have to acquire certain skills in order to be successful. These skills include: 1. Careful and thorough observation. 2. Accurate recording of what has been observed. 3. Organizing the observed and recorded information. 4. Repeating tests to make sure observation are accurate. 5. Forming conclusion from observation. 6. Predicting possible outcomes of similar experiments. Therefore, all students of Chemistry should acquire these skills so as to be able to think more clearly, logically and even critically while studying the subject.

The importance of chemistry in life.

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 two hazardous 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.

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.