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: 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 the 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