## Ideal Gas Internal Energy

$w=-P\Delta V$
and
$w=-\int_{V_{1}}^{V_{2}}PdV=-nRTln\frac{V_{2}}{V_{1}}$

Ariel Fern 2B
Posts: 105
Joined: Fri Aug 30, 2019 12:17 am

### Ideal Gas Internal Energy

An equation was brought up for an ideal gas that states:

U = 3/2 nRT

Where did this equation come from, and what should it be used for? Thanks so much!

Kimberly Koo 2I
Posts: 99
Joined: Sat Aug 17, 2019 12:17 am

### Re: Ideal Gas Internal Energy

I found this in a helpful table in section 4C.3 of the textbook. It is part of a set of values that correspond to what the values of Cv,m and Cp,m would be depending on if the question asks about an atom, linear molecule, or nonlinear molecule.

AronCainBayot2K
Posts: 101
Joined: Fri Aug 30, 2019 12:17 am

### Re: Ideal Gas Internal Energy

This value usually denotes Cv or Cp. The number depends on if the molecule is monoatomic, diatomic, etc.

Abigail_Hagen2G
Posts: 107
Joined: Fri Aug 09, 2019 12:17 am

### Re: Ideal Gas Internal Energy

It's an approximation for the heat capacity of a molecule.

Caroline Beecher 2H
Posts: 51
Joined: Wed Nov 14, 2018 12:21 am

### Re: Ideal Gas Internal Energy

Also, Dr. Lavelle mentioned in class today that we will be given those equations or the heat capacities for those specific molecules. I think we will mainly use this concept for monatomic molecules.