Calculate the velocity of sound in a mixture of gases made up of 2 parts by volume of oxygen, one part by volume of carbon dioxide and 3 parts by volume of nitrogen, all volumes measured at NTP. `gamma=1.4` for nitrogen and oxygen and `gamma = 1.31` for carbon dioxide. R = 8.4 `J//"mole-K"`.

Explanation

Because the mixture of gases is made up of two parts by volume of oxygen, one part by volume of carbon dioxide, and three parts by volume of nitrogen, the molecular weight of the mixture
`M_m=((2xx32)+(1xx44)+(3 xx 28))/(2 +1+3)`
`М_m=32 g`
The ratio of specific heats of the mixture
`gamma_m=(1.4xx2/6)+(1.31xx1/6)+(1.4xx3/6)`
`gamma_m= 1.385`
The velocity of sound in the gaseous mixture
`v=sqrt((gamma RT)/(M))=sqrt((1.385 xx 8.4 xx 273)/(32xx10^(-3))) = 315 m s^(-1)`