Two monoatomic ideal gases 1 and 2 of molecular masses, respectively are enclosed in
separate containers kept at the same temperature. The ratio of the speed of sound in gas 1 to that in gas 2
is
The speed of sound in gas of bulk modulus B and density ρ is given by
Now, for a perfect gas, PV = nRT. Differentiating at constant T, we get
If m is the mass of the gas and M its molecular mass, then