Difference between Cv and Cp?

$\Delta S = \frac{q_{rev}}{T}$

Emil Velasco 1H
Posts: 96
Joined: Wed Nov 21, 2018 12:19 am

Difference between Cv and Cp?

Do they represent the same value or no?

I looked some stuff up and what I've seen has varied

Leyna Dang 2H
Posts: 104
Joined: Thu Jul 25, 2019 12:17 am

Re: Difference between Cv and Cp?

Cv is for constant volume and Cp is constant pressure. I don’t think they’re the same value.

505316964
Posts: 95
Joined: Thu Jul 11, 2019 12:17 am

Re: Difference between Cv and Cp?

Cv is heat capacity at constant volume and Cp is heat capacity at constant pressure.
For atoms that are ideal gases:
Cv: 3/2 R
Cp: 5/2 R

RobertXu_2J
Posts: 104
Joined: Fri Aug 30, 2019 12:17 am

Re: Difference between Cv and Cp?

Cv is for constant volume, Cp is for constant pressure. For MONOATOMIC atoms, Cv is 3/2R and Cp is 5/2R, but for diatomic ones, Cv is 5/2R and Cp is 7/2R

Sydney Myers 4I
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Joined: Fri Aug 09, 2019 12:17 am

Re: Difference between Cv and Cp?

The values differ because the heat capacity of a gas can be calculated with either a constant volume or a constant pressure. When it's calculated with a constant pressure, the gas can lose energy by doing work on whatever boundary is present, which makes the amount of energy to change its temperature slightly different because some of the energy supplied is used to do work instead of heat up the gas.

Sidharth D 1E
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Joined: Sat Aug 24, 2019 12:17 am

Re: Difference between Cv and Cp?

Also, for nonlinear molecules, Cv is 3R and Cp is 4R

kevinolvera1j
Posts: 103
Joined: Fri Aug 02, 2019 12:15 am

Re: Difference between Cv and Cp?

For ideal gases, Cp = Cv + R. The actual value of Cv will differ depending on whether it is monoatomic, linear (diatomic), and nonlinear.

EvanWang
Posts: 101
Joined: Sat Sep 07, 2019 12:16 am

Re: Difference between Cv and Cp?

Cv is the specific heat of a substance under constant pressure, while Cp is the specific heat of a substance under constant pressure. Generally, Cv is lower because a system at constant volume does no work, so all of the energy inputed into the system will be used toward increasing the temperature.

Martina
Posts: 111
Joined: Thu Jul 25, 2019 12:16 am

Re: Difference between Cv and Cp?

Cv is 3/2 R and is used under constant volume and Cp is 5/2 R and is used under constant pressure.