Question

convert Acetic Acid into chloro methane​

Answer 1

By Decarboxylation of Acetic Acid. The Name of this reaction is Oakwood reaction.

Explanation:

Decarboxylation converts Carboxylic Acid into Alkane having one Carbon atom less than the parent Carboxylic Acid.

Answer 2

Answer:
There are two ways of converting acetic acid into chloromethane.

1.) First method: Decarboxylation followed by chlorination
1.1.) The pre-decarboxylation step
CH3COOH(aq) + NaOH => CH3COONa(aq) + H2O
1.2.) The decarboxylation step
CH3COONa(dry) + NaOH =(300C)=> CH4(gas) + Na2CO3(solid)
1.3.) The photochlorination step
CH4(gas) + Cl2(gas) =(blue light or UV, -30C)=> CH3Cl(liquid) + HCl(gas)
The last step has to be carried with a stoichiometric excess of methane at -30C so the methyl chloride formed immediately liquifies and separates from the reaction mixture and can't react with more chlorine to form DCM, chloroform and carbon tet.

2.) Second method: Direct decarboxylative halogenation, some Hunsdiecker-like reaction. The classic one uses the silver salt:
2.1.) Get silver acetate from silver oxide:
2 CH3COOH(aq) + Ag2O => 2 CH3COOAg(aq) + H2O
2.2) React the dry salt with a source of chlorine in carbon tetrachloride:
CH3COOAg(dry) + SO2Cl2 =(CCl4)=> CH3Cl(gas) + SO2(gas) + AgCl(solid)