Question

When excess chlorine reacts with methane in presence of sunlight, which is the major product?

(a) Refrigerant – 40

(b) Methylene chloride

(c) Chloroform

(d) Carbon tetrachloride

I had been asked this question in homework.

The doubt is from P-Block Elements topic in division P-Block Elements of Chemistry – Class 12

Answer 1

The correct answer is (d) Carbon tetrachloride

The best I can explain: In presence of sunlight, a free radical substitution reaction takes place between the reacting methane and chlorine molecules where in each elementary reaction a hydrogen atom is replaced by a chlorine atom in the new product. First, methane converts to 1-chloromethane which in turn produces dichloromethane followed by tri-chloromethane and tetra-chloromethane, respectively.