## Molar Heat Capacity

$\Delta U=q+w$

Jasmine_Brownfield_3E
Posts: 9
Joined: Wed Sep 21, 2016 2:55 pm

### Molar Heat Capacity

How do pressure and volume affect the molar heat capacity of an ideal gas?

Marie_Bae_3M
Posts: 25
Joined: Wed Sep 21, 2016 2:57 pm

### Re: Molar Heat Capacity

I'm not sure if this is what you meant, but the ideal gas law is PV=nRT. In other words n=PV/(RT). If we plug in PV/(RT) into the molar heat = moles * molar heat capacity* change in temperature, molar heat capacity=molar heat / ((PV/(RT))*change in temperature)=molar heat*RT/(PV*change in temperature), so i guess small pressure, volume means higher molar heat capacity?

Monica Habashy 3A
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### Re: Molar Heat Capacity

Basically when you have constant volume of 1 atom of an ideal gas the molar heat capacity is 3/2R (R is rydberg's constant) Whereas if you have constant pressure of 1 atom of a gas the molar heat capacity is 5/2R. Now if you have linear molecules or non linear molecules these values differ. There's a chart on page 281 that explains this.