Calculate the internal energy of a diatomic (rigid) gas molecule at `27^(@)C`. Estimate `C_(p) and C_(v)`.

Explanation

Interal energy = `dU=(f)/(2)RdT`.
where f = 5 for a rigid diatomic gas molecules
`therefore " " dU=(5)/(2)xx8.312xx320=6.234xx10^(3)J`
but `C_(v)=(f)/(2)RandC_(p)=(f)/(2)R+R=R((f+2)/(2))`
i.e. `C_(v)=(5)/(2)xx8.312=20.78j"mole"^(-1)K^(-1).`
`C_(p)=((5+2)/(2))xx8.312=29j"mole"^(-1)K^(-1).`