3/2R & 5/2R

isochoric/isometric:
isothermal:
isobaric:

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Clarice Chui 2C
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3/2R & 5/2R

Postby Clarice Chui 2C » Wed Feb 12, 2020 11:26 am

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

Kevin Xu 4F
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Re: 3/2R & 5/2R

Postby Kevin Xu 4F » Wed Feb 12, 2020 11:33 am

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

Postby 805307623 » Fri Feb 14, 2020 10:39 am

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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Re: 3/2R & 5/2R

Postby Oduwole 1E » Fri Feb 14, 2020 1:16 pm

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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Re: 3/2R & 5/2R

Postby Hui Qiao Wu 1I » Sun Feb 16, 2020 2:18 pm

mcat/ncat also incorporates Cv and Cp sometimes.

Jesalynne 2F
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Re: 3/2R & 5/2R

Postby Jesalynne 2F » Sun Feb 16, 2020 5:21 pm

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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Re: 3/2R & 5/2R

Postby Vinita Saxena 2I » Sun Feb 16, 2020 5:57 pm

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

Postby Callum Guo 1H » Sun Feb 16, 2020 5:59 pm

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

Shutong Hou_1F
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Re: 3/2R & 5/2R

Postby Shutong Hou_1F » Sun Feb 16, 2020 10:33 pm

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.

Keya Jonnalagadda 1A
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Re: 3/2R & 5/2R

Postby Keya Jonnalagadda 1A » Sun Feb 16, 2020 10:42 pm

I believe Cp and Cv could be used when finding the entropy change of an ideal monatomic gas, such as in Pizza Rolls 5: We are given the initial mass and volumes of two gases, told that they are ideal monatomic gases, and asked to find the change in entropy as they are mixed and the temperature increases. In this case, we need to use nCvln(T2/T1) to find the entropy of the combined gases.


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