Compute the value of the molar heat capacity at constant volume, CVCV, for CO2CO2 on the assumption that there is no vibrational energy. (Note: CO2CO2 is linear; SO2SO2 and H2SH2S are not. Recall that a linear polyatomic molecule has two rotational degrees of freedom, and a nonlinear molecule has three.)

Explanation:

Molar heat capacity at constant volume Cv  of a gas = n x .5 R where n is degree of freedom of the gas molecules

CO₂ is a linear molecule , so number of degree of freedom =  3 + 2 = 5

3 is translational and 2 is rotational degree of freedom . There is no vibrational degree of freedom given .

So Cv = 5 / 2 R

= 2.5 R .