Question

Two gases A and B having the same volume diffuse through a porous partition in 20 and 10 seconds respectively. The molecular mass of A is 49 u. Molecular mass of B will be :

Answer 1

The solution is provided in the attachment.

Answer 2

Solution for the molecular mass of B:

The time taken by gas A to diffuse in terms of volume through a porous partition is 20 sec.

The time taken by gas B to diffuse in terms of volume through a porous partition is 10 sec.

The molecular mass of the substance A is 49 u.

Using Graham's Law of Diffusion, we find the ratio of rate of diffusion with Molecular Mass.

$\frac{r(A)}{r(B)}=\sqrt{\frac{m B}{M A}}$

$\frac{10}{20}=\sqrt{\frac{M(B)}{49}}$

$M(B)=\frac{49}{4}=12.254$

Therefore, the molecular mass of element B is 12.254 u.