Chemistry is defined as that branch of science deals with the study of composition, structure and properties of matter and the changes which the matter undergoes under different conditions and laws which govern these changes.
Importance of chemistry
(1) Supply of Food
(1) It has provided chemical fertilizers such as urea ,calcium superphosphate, sodium nitrate, Ammonium Sulphate which have increased the yield of fruits ,vegetables and other crops.
(2) It has helped to protect the crops from insects and harmful bacteria by the use of certain effective insecticides ,fungicides and pesticides.
(3) The use of preservatives has helped to preserve food products for longer period.
(4) It has given methods to test the presence of adulterants there by ensuring the supply of pure food stuff.
(2) Contribution to better health and sanitation
1)It has provided mankind with a large number of life saving drugs. Dysentery and pneumonia are curable due to discovery of sulphur drugs and penicillin. life saving drugs like cisplatin and taxol have been found to be effective for cancer therapy and AZT is used for AIDS victim.
Analgesics have reduced pain of different types.
Antibiotics have helped to curb infection and cure diseases.
Tranquilizers have help to reduce tension and bring about calm and peace to patients suffering from mental diseases.
Antiseptics such as dettol are used to stop infection of the wounds.
Disinfectants are used to kill the microorganism present in toilets ,floor and drains.
(2) Discovery of anaesthetics has made surgical operations more and more successful.
(3) The use of insecticides such as DDT and Gammexane has reduced the hazards of diseases caused by the rats, mosquitoes and flies.
(3) Saving the environment
Refrigerators like chlorofluorocarbons which destroy the Ozone Layer have been replaced by environment friendly chemicals.
(4) Increase in comfort, pleasure and luxuries
(1) Synthetic fibres such as terylene ,nylon ,rayon which are more comfortable ,durable and attractive. They are easy to wash ,dry quickly and do not need ironing.Chemistry has provided with a large number of synthetic dyes which imparts bright and fast colour to the clothes.
(2) Building materials : By supplying steel and cement, chemistry has helped in the construction of safer homes and multi storage buildings and dams and bridges which can last for centuries .
(3) Supply of metals :Metals like gold, silver ,copper ,iron ,aluminium ,zinc and large number of the alloys are used for making ornaments ,utensils ,coins and many Industrial and agricultural implements.
(4) Articles of domestic use :Chemistry has made our homes more comfortable by supplying a large number of articles of domestic uses such as detergents ,oils and fats ,sugar ,paper, glass, plastic, paints, cosmetics, perfumes ,cooking gas etc. By use of refrigerants like ammonia, liquid sulphur dioxide and freon we can make our homes cooler in summer.
(5) Entertainment: Cinema ,video cameras ,simple cameras make use of films which are made of Celluloid and coated with suitable Chemicals. Fireworks which amuses us on festival and marriages are chemical products.
(5) Transport and communication
All means of transport use either petrol or diesel or coal which are all chemical products.
(6) Nuclear atomic energy
Chemistry has come to the rescue by providing an alternative source of energy which is nuclear energy .
(7) Application in industry
Chemistry has played an important and useful role towards the development and growth of number of industries such as glass ,cement ,paper, textile ,leather ,dye, Paints ,pigments ,petroleum ,sugar ,plastics ,Pharmaceuticals. It has also help in the greater production of sulphuric acid, nitric acid Ammonia hydrogenated oils by providing suitable catalyst.
(8) Application in war
It is responsible for the discovery of highly explosive substances such as TNT, nitro glycerine and dynamite, poisonous gases like mustard gas,Phosgene etc.
Problems caused by progress in chemistry
(1) Nuclear energy is useful but disposal of nuclear waste poses a serious problem to humanity.
(2) Phonograph records have added to our pleasure for listening music but they are made of polyvinyl chloride produced from vinyl chloride which can cause liver cancer in industrial workers.
(3) Antibiotics have eliminated infections diseases but the overuse is very harmful.
(4) Insecticides have increased the food supply but they do a lot of harm to birds ,fishes and useful insects.
(5) Use of Polythene bags is posing a serious threat to sewage system.
(6) Chemistry has given drugs like LSD , cocain, brown sugar which are providing a curse to the society.