Question

Find the molar mass and the number of degrees of freedom of molecules in a gas if its heat capacities are `C_(v) = 650 J kg^(-1) K^(-1)` and `C_(P) = 910 J kg^(-1) K^(-1)`

Answer 1

`C_(V) = (R )/(gamma -1)`
and `C_(V) = Mc_(v)`
`:. M xx 650 = (8.3)/(gamma -1)`
Futher
`gamma C_(p) // C_(v) = (910)/(650)`
Solving Eqs. (i) and (ii), `M = 32 g//mol`
`gamma - 1,4`, so the gas is diatomic and the number of degrees of freedom is 5.