The molar mass of the unknown gas

Question

A sample of N2 gas is observed to effuse through a pourous barrier in 1.93 minutes. Under the same conditions, the same number of moles of an unknown gas requires 2.97 minutes to effuse through the same barrier.

The molar mass of the unknown gas is __________

Answer 1

Comparing the rate of effusion of the two gases:

Rate of effusion of gas 1 = (Molar mass of gas 2)^0.5

Rate of effusion of gas 2 (Molar mass of gas 1)^0.5

You have the rate of effusion of both the gases as well as the molar mass of Nitrogen.

Assign Nitrogen molar mass and effusion rate with coefficient 2 and the unknown one with coefficient 1.