350 Cm3 of CH4 and 175Cm3 of an unknown gas 'A' diffused in the
same time under similar conditions. The molecular mass of gas A is

Since rate of diffusion is directly proportional to volume, so r1/r2=v1/v2 r1/r2=350/175 r1/r2=2--------(i) Rate of diifusion is inversely proportional to molucular mass,so r1/r2=√M2/√M1 r1/r2=√M2/√16 r1/r2=√M2/4-----(ii) Since (i)=(ii) 2=√M2/4 2*4=√M2 (8)^2=M2 64g=M2