How do we get benzene from acetylene? Give the corresponding equation. Explain the halogenation, alkylation, acylation, nitration and sulphonation 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)) underset("Cu tube")overset("Red hot")to underset("Benzene")(C_(6)H_(6))`
Properties:
1. Halogenation: In presence of anhydrous `AlCl_(3)`, benzene reacts with `Cl_(2)` and gives chloro-benzene.

2. Friedel -Craft alkylation: In presence of `AlCl_(3)`, benzene reacts with alkyl halides and gives benzene. This is known as Friedel Craft's alkylation.

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

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

A mixture of conc. `H_(2)SO_(4) and" conc "HNO_(3)` in 1:1 ratio (by volume) is called nitration mixture.
5. Sulphonation: Benzene reacts with funning `H_(2)SO_(4)` and gives benzessulphuric acid.