Question

If two different gases are in
molar ratio n, : n2, then which of
the following need not be in the
ratio n, : n?

Answer 1

ANSWER

The rate of effusion is directly proportional to the mole fraction and inversely proportional to the square root of molar mass.

r′r=V′V×tt′=X′X×MM′

Here, r,V,t,X and M are the rate of diffusion, volume diffused, time for diffusion, mole fraction and the molar mass for He respectively 

and r′,V′,t′,X′ and M′ are the rate of diffusion, volume diffused, time for diffusion, mole fraction and the molar mass for methane respectively 

XX×5t′=12×416

t′=40sec

Hence, the time required to effuse same volume of methane gas is 40 sec.