If 30cm3 of oxygen diffuses through a porous pot in 7 seconds, how long will it take 60cm3 of chlorine to diffuse through the same pot, if the vapour densities of oxygen and chlorine are 16 and 36 respectively?
-
A.
9.3 sec -
B.
14 sec -
C.
21 sec -
D.
28 sec -
E.
30.3 sec
Correct Answer: Option C
Explanation
The rate of diffusion of a gas is proportional to the square root of the density.16 and 7 secs36 or 6 will be proportional to
7/16 x 6
7/4 x 6
But volume of chlorine is twice that of oxygen. The rate of escape of chlorine is
2/1 x 7/4 x 6/1 = 7 x 3; = 21 sec