## Internal Energy, U

smurphy1D
Posts: 51
Joined: Mon Nov 18, 2019 12:18 am

### Internal Energy, U

Is Delta U always equal to Delta H?

Sally Qiu 2E
Posts: 105
Joined: Fri Aug 30, 2019 12:18 am

### Re: Internal Energy, U

it's equal if you are at constant pressure and volume.

Juliana Chopelas 1A
Posts: 50
Joined: Sat Aug 24, 2019 12:16 am

### Re: Internal Energy, U

delta u is only equal to delta h when pressure is constant and volume doesn't change

Posts: 102
Joined: Wed Sep 18, 2019 12:18 am

### Re: Internal Energy, U

A counter example would be in an isolated system, where neither heat nor matter can be exchanged, dU = q + w.

preyasikumar_2L
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

### Re: Internal Energy, U

ΔH = ΔU + PΔV

ΔU is only equal to ΔH when the pressure is constant and the change in volume ΔV = 0.

Matthew Chan 1B
Posts: 111
Joined: Sat Sep 07, 2019 12:16 am

### Re: Internal Energy, U

Only at constant pressure and volume! :)

Jesse Anderson-Ramirez 3I
Posts: 54
Joined: Thu Sep 26, 2019 12:18 am

### Re: Internal Energy, U

Only when change in pressure and change in volume are zero.

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