Question

The molar specific heat of a gas as given from the kinetic theory is `(5)/(2) R`. If it is not specified whether it is `C_(p) or C_(upsilon)` one could conclude that the molecules of the gas
A. are definitely monoatomic
B. are definitely rigid diatomic
C. are definitely non-rigid diatomic
D. can be monoatomic or rigid diatomic

Answer 1

Correct Answer - D
A monoatomic gas has 3 degree of freedom and diatomic gas has 5 degrees of freedom.
For monotomic gas, `C_(upsilon) = 3/2 R and C_(p)=C_(upsilon) + R`
`or C_(P) = 3/2 R + R = 5/2R`
For a ditomaic gas, `C-(upsilon) =5/2 R, C_(upsilon)+R`
=5/2R+ R=7/2 R`
Hence we can conclude that the molecules of the gas can b monoatomc and rigid diatomic.