## 5/2R vs 3/2R

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

Briana Yik 1H
Posts: 30
Joined: Fri Sep 28, 2018 12:20 am

### 5/2R vs 3/2R

how do we know when to use 5/2R versus 3/2R?

lizettelopez1F
Posts: 29
Joined: Fri Sep 28, 2018 12:19 am

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

Cp=5/2r is used when you need to find the heat capacity of an ideal gas with a constant pressure. Cv=3/2R is used when you need to find the heat capacity of an ideal gas with a constant volume

KatrinaPho_2I
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Joined: Fri Sep 28, 2018 12:28 am

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

These values only work if you are dealing with monoatomic ideal gases.

abbydouglas1K
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Joined: Fri Sep 28, 2018 12:26 am

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

If the question says that the pressure is being kept constant(Cp) or that the volume is being kept constant (Cv) you will use 5/2R and 3/2R respectively if the molecule in question is a monatomic gas.

Christopher Anisi 2K
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Joined: Fri Sep 28, 2018 12:21 am

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

For a monoatomic gas under a constant pressure the Cp value is equal to 5/2R however if it is under a constant volume the Cv value is equal to 3/2R.

Morgan Carrington 2H
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Joined: Wed Nov 14, 2018 12:22 am

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

KatrinaPho_2I wrote:These values only work if you are dealing with monoatomic ideal gases.

What does you mean by a monoatomic gas?

Claire_Kim_2F
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Joined: Wed Sep 30, 2020 10:02 pm

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

Monoatomic gases are gases that are noble gases like halogen and other substances.

John Calonia 1D
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Joined: Wed Sep 30, 2020 9:49 pm

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

What are the different heat capacities involving R of different types of molecules and is the general rule +1 R for constant pressure.

Posts: 94
Joined: Wed Sep 30, 2020 9:40 pm

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

Monoatomic gases are gases that are noble gases like halogen and other substances.

Almost! Monoatomic gases are gases with only one atom, so it would just be noble gases. Halogens are diatomic gases.