The specific heat of the mixture of two gases at constant volume is `(13)/(6) R`. The ratio of the number of moles of the first gas to the second gas is 1:2.
The respective gases may be

Options

A. `O_(2) and N_(2)`
B. He and Ne
C. `He and N_(2)`
D. ` N_(2) and He`

Answer

C

Explanation

`C_(v_(mix)) = (n_(1)C_(V1) + n_(2)C_(V2))/(n_(1) + 2n_(1)) " "[because (n_(1))/(n_(2)) = (1)/(2)]`
`rArr (13R)/(6) = C_(V1) + 2C_(V2)`
Possible values are,
`C_(V1) = (3R)/(2),C_(V2) = (5R)/(2)`
`therefore ` Gases are monatomic (like he) and diatomic (like `N_(2)`)