Class 12

Chemistry

Gases & Solutions

States Of Matter

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

- 12.25 u
- 6.50 u
- 25.00 u
- 50.00 u

rate of diffusion

$r∝M 1 ,r∝tV $

where, V is the volume of the gas diffused in time t.

$r_{B}r_{A} =M_{A}M_{B} ort_{A}V_{A} ×V_{B}t_{B} =M_{A}M_{B} $

$Given,V_{A}=V_{B}$

$∴2010 =49M_{B} ⇒41 =49M_{B} $

$M_{B}=449 =12.25u$