For a rigid diatomic molecule, univerisal gas constant `R = mc_(p)`, where `'C_(p)'` is the molar specific heat at constant pressure and 'n' is a number. Hence n is equal to

Options

A. 0.2257
B. 0.4
C. 0.2857
D. 0.3557

Answer

C

Explanation

For a rigid diatomic molecule,
`gamma=C_(P)/C_(V)=7/5`
`thereforeC_(V)=5/7C_(P)`
`thereforeC_(P)-C_(V)=R`
`thereforeC_(P)-5/7C_(P)=R`
`therefore2/7C_(P)=R" "...(1)`
It is given that `R=nC_(P)" "…(2)`
Comparing (1) and (2), we get
`n=2/7=0.2857" "` ...Option ( c)