Question

Rate of diffusion of nitrogen is 9 $ml/sec$ and for another gas $X$ the rate of diffusion is 6 $ml/sec$. Molecular weight of $X$ is:

• A. 63
• B. 126
• C. 31.5
• D. 56

Answer 1

Answer: (A)

63

Rate of diffusion of nitrogen $=9$ ml/sec

Rate of diffusion of gas $X=6$ ml/sec

According to Graham's law of diffusion,

$\frac{{rate}_1}{{rate}_2}=\sqrt{\frac{M_2}{M_1}}⟹\frac{9}{6}=\sqrt{\frac{X}{28}}⟹\frac{9}{4}\times 28=X$

$X$ (Molar mass) $=63$