## U:Internal Energy

Meachelle_Lum_1I
Posts: 92
Joined: Fri Sep 28, 2018 12:24 am

### U:Internal Energy

What's the difference between
1) deltaU= q+w
and
2) deltaU= deltaH -PV

Is the second equation only for constant pressure? Are there certain circumstances to use each equation or are they interchangeable?

Toru Fiberesima 1L
Posts: 63
Joined: Fri Apr 06, 2018 11:02 am

### Re: U:Internal Energy

They are essentially the same. It just depends which values you are given in the question, and which you can plug into the equation.

Julia Lung 1I
Posts: 30
Joined: Fri Jun 23, 2017 11:39 am

### Re: U:Internal Energy

They can both be used to find delta U depending on what's given in the problem. We also went over that when there is no volume change (in most of biology) then delta U = delta H.

josie 1C
Posts: 18
Joined: Fri Sep 28, 2018 12:19 am

### Re: U:Internal Energy

They are basically the same, you just pick which one you use based on what information you are given in the question.

chrisavalos-2L
Posts: 63
Joined: Fri Sep 28, 2018 12:18 am

### Re: U:Internal Energy

Essentially they are the same equation you would just use one or the other depending on the information that is given in the problem.