Prepare benzene from acetylene, write equation. Explain the Friedel - Crafts's alkylation, Friedel - Crafts's acylation sulphonation reaction of benzene.

Explanation

Preparation of benzene from acetylene : When acetylene gas is passed through red hot copper tube, it undergoes polymerisation forming benzene .
`underset("Acetylene")(3C_(2)H_(2))overset("Ret hot")underset("Cu tube")(to)underset("Benzene")(C_(6)H_(6))`
Properties :
1) Friedel - Craft.s alkylation : In presence of `AlCl_(3)` benzene reacts with alkyl halides and gives alkyl benzene . This is known as Friedel Craft.s alkylation .

2) Friedel - Craft.s acylation : In presence of `AlCl_(3)`, benzene reacts with acetyl chloride and gives acetophenone .

3) Sulphonation : Benzene reacts with fuming `H_(2)SO_(4)` and gives benzenesulphonic acid .

4) Halogenation : In presence of anhydrous `AlCl_(3)` benzene reacts with `Cl_(2)` and gives chloro-benzene .

5) Nitration : Benzene reacts with nitration mixture below `60^(@)C` and gives nitro-benzene .

A mixture of conc. `H_(2)SO_(4)` and `HNO_(3)` in `1:1` ratio (by volume) is called nitration mixture .