## U=3/2 nRT

$\Delta U=q+w$

Norman Dis4C
Posts: 101
Joined: Sat Sep 28, 2019 12:16 am

### U=3/2 nRT

Can someone explain the idea of the equation U=3/2 nRT and how it is used?

Daria MacAuslan 1H
Posts: 50
Joined: Sat Aug 17, 2019 12:16 am

### Re: U=3/2 nRT

I dont think we covered this in class so I am unsure if it is necessary for the exam, especially since we focused more on changes in internal energy, rather than fixed amounts...

Jared Khoo 1G
Posts: 107
Joined: Wed Sep 18, 2019 12:16 am

### Re: U=3/2 nRT

U is the same as Eth I believe, which is the thermal energy an object has. Therefore, U is also determined by temperature and is equal to the average kinetic energy per mole multiplied by the number of moles (n).

AniP_2D
Posts: 95
Joined: Sat Aug 17, 2019 12:17 am

### Re: U=3/2 nRT

You would use this equation when you are asked to find deltaU at a constant volume.

Justin Quan 4I
Posts: 104
Joined: Sat Sep 14, 2019 12:17 am

### Re: U=3/2 nRT

To add on, ∆U=3/2 nRT comes from the equation ∆U = q + w. Under constant volume conditions, w=0, thus ∆U = q. Since q = n C ∆T and Cv=(3/2) R, we get the equation ∆U=3/2 nRT.