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;
[tex] \frac{rate of diffusion of gas A X \sqrt{mol wt of gas B} }{rate of diffusion of gas B X \sqrt{mol wt of gas A} } =1[/tex]
here the mol wt of gas B is not known so we take it as 'x'
on solving we get 7 X [tex] \sqrt{x} [/tex] / 4.9 X [tex] \sqrt{41} [/tex]
mol. wt of unknown gas = 20.0 g
