Question

One litre of a gaseous mixture of two gases effuses in 311 seconds while 2 litres of oxygen takes 20 minutes. the vapour density of gaseous mixture containing ch4 and h2 is

Answer 1

The diffusion law of Graham says the amount of diffusion of gas is actually inversely proportional to square root of the molecular weights or density.  

The r2 and r1 are rates of the diffusion of two gases.

The molecular weight of the oxygen gas is 32.

While applying the above law, we can get the answer is 4.3 gm.