The density of a polyatomic gas in standard conditions is 0.795 kgm-3. The specific heat of the gas at constant volume is

standard pressure P=1.013×105 pascal; temperature T=273K; density=0.795kgm-3 PV=mrT   ;here r=specific gas constant; m=mass of gas;V=volume of gas ⇒P=(m/V)rT ⇒P=ρrT   ; here ρ =density of gas ⇒r=P/ρT ⇒r=1.013×1050.795×273=466.7 ∴ we know CV=rγ-1=specific heat of gas at constant volume;specific heat ratio γ=43;substitute legibly CV=466.743-1=1400JKg-1 K-1