Question

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

• A. 2
• B. 8
• C. 64
• D. 128

Answer 1

Answer: (C)

64

Answer 2

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 $=32 \times 2=64$