Question

Vapour density of a volatile substance is $4\left(C{H}_4=1\right)$. Its molecular weight would ho.

• A. 2
• B. 8
• C. 64
• D. 128

Answer 1

Answer: (C)

Actual vapour density of methane
$=\frac{\text{ mol. wt }}{2}=\frac{16}{2}=8$
$\therefore$ vapour density of volatile substance $=8\times 4=32$
Molecular weight of the substance $=32\times 2=64$