Under certain conditions neon gases diffuse at a rate of 7.0 cm/s under the same conditions as an on known gas defuses at a rate of 4.9 per second what is the approximate molar mass of the unknown gas?

Answer : To find the molar mass of unknown gas we need to solve the equation of rate of diffusion and molecular weight of the gases, which is as follows;



here the mol wt of gas B is not known so we take it as 'x'

on solving we get 7 X  / 4.9 X 

mol. wt of unknown gas = 20.0 g