In kinetic theory of ideal gas, mean speed also known as average

speed is given as

Where R=gas constant=8.31Jmol^-1K^-1

T=temperature of gas

M=molar mass of gas

Molar mass of hydrogen molecule M(H)=2 amu

Molar mass of nitrogen molecule M(N)=28 amu

Mean speed of hydrogen molecule=

Mean speed of nitrogen molecule=

Temperature of both the gases is same.

Dividing equation (II) and (III) we get

The ratio of the mean speed of hydrogen molecules to the mean speed of nitrogen molecules in a sample containing a mixture of the two gases is 3.74.