Find the molecular weight for a gas in which the velocity of sound is `1260(m)/(s)` at `0^@C` and whose `gamma` is 1.4.

Explanation

`C=sqrt((gammaP)/(rho))`
`1260=sqrt((1.4P)/(rho))`
`(P)/(rho)` of the gas at `0^@C=11.34xx10^5`
`P=(rho)/(M)RT` is the perfect gas equation in terms of density
`(P)/(rho)=(RT)/(M)`
`M=(8.3xx273)/(11.34xx10^5)=2xx10^-3kg=2g`