Question

Vapour density of a volatile substance w.r.t. CH4 is 4 (CH4=1). Its molecular weight would be

Answer 1

The molecular weight or the molar mass would be 64 because vapor density is related with molecular mass as

molar mass 2×V.D

In methane CH4 molar mass =16

Thus vapor density =162=8

Here relative vapor density is 4 for the substance so it is =8×4=32

Hence Molar mass of the substance =2×32=64

Answer 2

here is the answer of your question..I hope you understand... thanks