The Total solution for NCERT class 6-12
Explain the following terms with suitable examples
(i) Cationic detergents
(ii) Anionic detergents and
(i) Cationicdetergent
Cationic detergents are quaternary ammonium salts ofacetates, chlorides, or bromides. These are called cationic detergents becausethe cationic part of these detergents contains a long hydrocarbon chain and apositive charge on the N atom.
For example: cetyltrimethylammonium bromide
(ii) Anionicdetergents
Anionic detergents are of two types:
1.Sodium alkyl sulphates: Thesedetergents are sodium salts of long chain alcohols. They are prepared by firsttreating these alcohols with concentrated sulphuric acid and then with sodiumhydroxide. Examples of these detergents include sodium lauryl sulphate (C11H23CH2OSO3−Na+)and sodium stearyl sulphate (C17H35CH2OSO3−Na+).
2.Sodium alkylbenzenesulphonates: These detergents are sodium salts of long chainalkylbenzenesulphonic acids. They are prepared by Friedel-Crafts alkylation ofbenzene with long chain alkyl halides or alkenes. The obtained product is firsttreated with concentrated sulphuric acid and then with sodium hydroxide. Sodium4-(1-dodecy) benzenesulphonate (SDS) is an example of anionic detergents.
(iii) Non-ionicdetergents
Molecules of these detergents do not contain any ions.These detergents are esters of alcohols having high molecular mass. They areobtained by reacting polyethylene glycol and stearic acid.