## Heat Capacity of Ideal Gases

Ariel Fern 2B
Posts: 105
Joined: Fri Aug 30, 2019 12:17 am

### Heat Capacity of Ideal Gases

Can someone explain the reasoning as to why the heat capacity of an ideal gas at constant pressure (Cp) is 5/2 R, and why at constant volume (Cv) it is 3/2 R? I got these values from the equation sheet, but I'm unsure of the derivation of the values!

205007651
Posts: 53
Joined: Tue Nov 13, 2018 12:17 am

### Re: Heat Capacity of Ideal Gases

I think they come from a formula in the first law of thermodynamics saying that the internal energy = 3/2nRT, which in turn comes from the kinetic energy equation. From there I unfortunately don't know how to further derive.