Explain the following terms with suitable examples:
$(i)$ Cationic detergents
$(ii)$ Anionic detergents
$(iii)$ Non-ionic detergents

(N/A) $(i)$ Cationic detergents
Cationic detergents are quaternary ammonium salts of acetates,chlorides,or bromides. These are called cationic detergents because the cationic part of these detergents contains a long hydrocarbon chain and a positive charge on the $N$ atom.
For example: Cetyltrimethylammonium bromide,which has the structure:
$[CH_3(CH_2)_{15}N(CH_3)_3]^+ Br^-$
$(ii)$ Anionic detergents
Anionic detergents are of two types:
$1.$ Sodium alkyl sulphates: These are sodium salts of long-chain alcohols. They are prepared by treating these alcohols with concentrated sulphuric acid followed by sodium hydroxide. Examples include sodium lauryl sulphate $(C_{11}H_{23}CH_2OSO_3^-Na^+)$ and sodium stearyl sulphate $(C_{17}H_{35}CH_2OSO_3^-Na^+)$.
$2.$ Sodium alkylbenzenesulphonates: These are sodium salts of long-chain alkylbenzenesulphonic acids. They are prepared by Friedel-Crafts alkylation of benzene with long-chain alkyl halides or alkenes,followed by treatment with concentrated sulphuric acid and then sodium hydroxide. Sodium $4-(1-dodecyl)$ benzenesulphonate is an example.
$(iii)$ Non-ionic detergents
Molecules of these detergents do not contain any ions. These detergents are esters of alcohols having high molecular mass. They are obtained by reacting polyethylene glycol and stearic acid.
$CH_3(CH_2)_{16}COOH + HO(CH_2CH_2O)_nCH_2CH_2OH \xrightarrow{-H_2O} CH_3(CH_2)_{16}COO(CH_2CH_2O)_nCH_2CH_2OH$