Explain the following types of substances with one suitable example, for each case : (3 marks)
(i) Cationic detergents.
(ii) Food preservatives.
(i) Cationic detergents : They are quaternary ammonium salts of amines with acetates,
chlorides or bromides as anions and the cationic part possess a long hydrocarbon chain, and a
positive charge on nitrogen atom. Therefore they are called cationic detergents.
Example : Cetyltrimethyl ammonium bromide
(ii) Food Preservatives : They are used to prevent spoilage of food due to microbial growth.
Example : Table salt, vegetable oils, sodium benzoate etc.
(iii) Analgesics : Analgesics reduce or abolish pain without causing impairment of consciousness,
mental confusion, in coordination or paralysis or some other disturbance of nervous system.
They are of two types :
(a) Non-narcotic analgesics
Example : Aspirin
(b) Narcotic analgesics
Example : Morphine