Chemistry, industry and the environment
A chemical industry is one that uses chemistry to make chemicals from other substances (raw materials). Each of these basic industrial materials is produced through the application of chemistry by chemists and chemical engineers.
Raw materials for chemical industry
Raw materials are starting materials, usually in an unrefined ( less useful) state which need to go through an industrial process, in order to be upgraded to their more useful forms.
There are two types of raw materials; the natural materials, which are known as basic raw materials, and second common chemical materials which have been produced as chemical intermediates. The important basic raw materials are as follows.
1. Air: the oxygen (air) is used in oxyacetylene (a very high temperature flame) for welding and cutting metals and steel. Nitrogen which is more important,is used in the haber process, for manufacturing ammonia gas.
2. Petroleum: it is an important raw material for fuels and petrochemicals from which other products and chemicals are made.
3. Limestone: calcium trioxocarbonate IV in the form of limestone, chalk and marble is the main source of lime or calcium oxide used in making cement and concrete.
4. Coal: the chemicals derived from coal are by-products of the process; bitumen coal is converted into coke.
5. Salt or sodium chloride: when sodium chloride is electrolyzed, it produces three important industrial chemicals namely; sodium hydroxide, hydrogen and chlorine. Sodium hydroxide is used in the manufacture of soap and in the textile and paper industry.
6. Metallic ores: Iron, aluminum and copper are used mainly in the construction of buildings, bridges, and in making machines, ships and aircraft.
7. Sulphur: it is used in many chemical processes and in the manufacture of fertilizers, paints, dyes, explosives, synthetic fibres and accumulators.
Divisions of the chemical industry
1. Heavy chemicals: these are chemicals which are essential to all the branches of the industry and are in such high demand that they are produced in large quantities e.g. sodium hydroxide, calcium hydroxide etc. Heavy chemicals are used in the processing of textiles, soaps, glass, paints etc.
2. Plastic: Plastic industry is divided into four categories, namely bags, household and kitchen wares, industrial plastic and miscellaneous items. Industrial plastic include items like casing for radios, cassettes, recorders, T.V sets, P.V.C. pipes and fittings for the building industry. Miscellaneous items include precision molding of plastics to produce gears, hubs and clamps for audio and video cassettes.
3.fertilizers: fertilizers are needed to increase crop yields to feed the world’s rapidly increasing population. Nitrogen, phosphorus and potassium compounds are mixed together in most of the fertilizers used nowadays. The proportion in which they are mixed is usually given as the N.P.K value.
4. Metallurgy: metallurgy is a very active branch of chemistries. The demands of modern industry have often led to the development of metals and alloys with new properties, from which also come some very useful by-products. Alloys with new properties are being developed for the aviation and space projects.
5. Fine chemicals: these are chemicals produced in small quantities, because they are manufactured for specific industrial and domestic purposes. Fine chemicals include dye stuffs, additives, analytical chemicals, perfumes and pigments for paint.
6. Pharmaceuticals: most pharmaceutical drugs are organic compounds, although some inorganic compounds are used as drugs e.g. bismuth trioxocarbonate IV is used to cure stomach disorders, potassium bromide is used as a sedative and Mercury (I) chloride is used as a purgative.
Antibiotics are one of the latest discoveries in the long list of drugs produced by the pharmaceutical industry and their discovery has led to a great improvement in man’s quest for a better life.
7. Soaps and detergents: soap is a chemical compound or a mixture of chemical compound resulting from the reaction between fatty oils or fats and alkalis. It is manufactured by introducing melted fats into excess sodium hydroxide solution and boiling the mixture. This process is called saponification.
Soaps and detergents have the property of reducing the surface tension of water. They are able to lift dirt from greasy surfaces. Detergents are used extensively in homes and factories.
8. Cement: the major raw materials for the cement industry are limestone and clay. Cement is made by heating a mixture of powdered limestone and clay which in turn is used in the construction of buildings and bridges after which it has been mixed to a paste with water and sand.
Concrete is a hard material which is obtained when cement is mixed with gravel and water. It was used in building and construction of dams and roads.
9. Glass: glass is a product of sand, soda, lime and other materials mixed together and melted in a furnace at a very high temperature. There are many kinds of glass. They may be transparent, translucent or coloured, depending on the purpose for which they are used.
10. Ceramics: the art of processing earthy materials into useful or ornamental objects through the application of strong heat is known as ceramics. Ceramics include cooking and water storage pots, dishes and cups, ceramic tiles and laboratory sinks.
11. Paints: paints are made from suspensions of solid coloured substances called pigments. When applied as a thin layer on a surface, paint produces an opaque solid film. It is used to decorate and protect a surface against weathering and corrosion.
1. These are examples of chemical industries except?
B. Solvay process
C. Electrolysis of brine
D. Contact process
2. Metallurgy is a scientific process which involves the following except
A. Manufacture of alloys
B. Manufacture of both natural and artificial catalyst
C. Refining of metals
D. Grading of metals
3. Chemicals that are produced in small quantities and with very high degree of purity are
A. Bulk chemicals
B. Fine chemicals
C. Heavy chemicals
D. Light chemicals
4. Examples of fine chemicals include the following except
A. Dye stuffs
D. Sodium hydroxide
5. Name any five divisions of chemical industries.
Answer: soaps and detergents, paints, heavy chemicals, fertilizers, and metallurgy
6. Defined chemical industry.
Answer: it is one that uses chemistry to make chemicals from other chemical substances (raw materials).
7. Name the two types of raw materials.
Answer: the natural materials and the common chemical materials
8. The basic raw materials for the chemical industry are the following except?