The density of a polyatomic gas in stantard conditions is `0.795 kg m^(-3)`. The specific heat of the gas at constant

Options

A. `930 J-kg^(-1) K^(-1)`
B. `1400 J-kg^(-1) K^(-1)`
C. `1120 J-kg^(-1) K^(-1)`
D. `1600 J-kg^(-1) K^(-1)`

Answer

B

Explanation

b. Ideal gas equation for `m` grams of gas is
`PV = mr T` (where `r=` specific gas constant)
or `P = (m)/(V) rT = rho rT`
`implies r = (P)/(rho T) = (1.013 xx 10^(5))/(0.795 xx 273) = 466.7`
Specific heat at constant volume
`c_(v) = (r )/(gamma - 1) = (466.7)/((4)/(3) -1) = 1400 J//kg-K`
`(gamma = 4//3` for polyatomic gas)