Question

For polyatomic molecules having 'f' vibrational modes, the ratio of two specific heats,Cp/Cv  is..........

Options

• `(1+f)/(2+f)`

•  `(2+f)/(3+f)`

•  `(4+f)/(3+f)`

• `(5+f)/(4+f)`

Answer 1

`(4+f)/(3+f)`

By the law of equipartition of energy, for one mole of polyatomic gas

`C_p=(4+f)R and C_v=(3+f)R`

`thereforeC_p/C_V=((4+f)R)/((3+f)R)=(4+f)/(3+f)`