## Molar Heat Capacity

Kimberly 1H
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Joined: Fri Sep 28, 2018 12:17 am
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### Molar Heat Capacity

Why is molar heat capacity of an ideal gas greater at a constant pressure greater than at a constant volume?

Samantha Man 1L
Posts: 63
Joined: Fri Sep 28, 2018 12:22 am

### Re: Molar Heat Capacity

Molar heat capacity is greater at constant pressure than at constant volume because at constant P, some of the heat goes into expansion work which means there will be less energy left over to raise the temperature unlike at constant V, where no expansion work is done so all the energy goes into raising the temperature.

Nicole Lee 4E
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### Re: Molar Heat Capacity

The equation Cp = Cv + R shows us that the heat capacity at constant pressure is higher than the heat capacity at constant volume.

Alondra Olmos 4C
Posts: 32
Joined: Fri Sep 28, 2018 12:21 am

### Re: Molar Heat Capacity

To expand on the previous two replies, the book gave the example of argon which has a constant volume heat capaccitg of 12.8, so when using the equation, you get 12.8 + 8.3= 21.1 for the constant pressure value. That is 65% greater than the constant volume value.