## 3/2R & 5/2R

isochoric/isometric: $\Delta V = 0$
isothermal: $\Delta T = 0$
isobaric: $\Delta P = 0$

Clarice Chui 2C
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Joined: Fri Aug 30, 2019 12:16 am

### 3/2R & 5/2R

Which is equation(s) would you be solving that uses Cv or Cp?

Kevin Xu 4F
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Joined: Fri Aug 09, 2019 12:16 am

### Re: 3/2R & 5/2R

Heat capacity at constant volume for an ideal gas is used whenever the volume is kept constant, in the case solving for q, delta U, and delta S. The only exception is delta H, which uses Cp because delta H does not equal q at constant volume.

Heat capacity at constant pressure for an ideal gas is used whenever the pressure is kept constant, in the case solving for q, delta H, and delta S. The only exception is delta U.

805307623
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### Re: 3/2R & 5/2R

Specific heat shows the amount of energy as heat needed to be provide to a system for the temperature of the system to have a unit rise. The value of it varies depending on the process providing this energy. Cv for a gas is the change in internal energy (U) of a system with respect to change in temperature at a constant volume. Cp for a gas is the change in the enthalpy (H) of the system with respect to change in temperature at a constant pressure.

Oduwole 1E
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Joined: Fri Aug 02, 2019 12:16 am

### Re: 3/2R & 5/2R

Clarice Chui 2C wrote:Which is equation(s) would you be solving that uses Cv or Cp?

Cv is the specific heat capacity you use for constant volume, and Cp is the specific heat capacity for constant pressure.

Hui Qiao Wu 1I
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Joined: Fri Aug 30, 2019 12:16 am

### Re: 3/2R & 5/2R

mcat/ncat also incorporates Cv and Cp sometimes.

Jesalynne 2F
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Joined: Wed Sep 18, 2019 12:18 am

### Re: 3/2R & 5/2R

Cp and Cv are used in finding the heat capacity. Cp is for constant pressure and Cv is for constant volume.

Vinita Saxena 2I
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Joined: Fri Aug 09, 2019 12:16 am

### Re: 3/2R & 5/2R

when using the specific heat capacity of a gas, they'll specify if it's under constant pressure or constant volume. That'll tell you which to use.

Callum Guo 1H
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### Re: 3/2R & 5/2R

Cp is constant pressure (5/2R) Cv is constant volume (3/2R)

Shutong Hou_1F
Posts: 117
Joined: Sat Sep 14, 2019 12:17 am

### Re: 3/2R & 5/2R

I think it would be under the situation that there is an ideal gas that is monoatomic, linear, or non-linear, and molar heat capacity is not given.