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

As we know, for rigid diatomic molecule.
`(C_(p))/(C_(v)) = 7/5`
`:. C_(v) = 5/7 C_(p) "…"(i)`
Also, `C_(p) - C_(v) = R`
`rArr C_(p) - 5/7 C_(p) = R` [ `:.` from Eq. (i)]
`rArr 2/7 C_(p) = R`
`:. n = 2/7 = 0.2857`