## Units

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

Kenan Kherallah 2C
Posts: 78
Joined: Fri Sep 28, 2018 12:17 am

### Units

When we are calculating work with either constant pressure or not, do we always have to use units of atm? Can we use pascals or bar or should we convert?

Kristen Kim 2K
Posts: 70
Joined: Fri Sep 28, 2018 12:16 am

### Re: Units

I would just use atm for everything, especially because R constant units are (L*atm)/(K mol).

Elisa Bass 4L
Posts: 61
Joined: Fri Sep 28, 2018 12:23 am

### Re: Units

It is important to know that there’s a slight difference between bars and atm (1.013 bar = 1 atm) but from the homework problems it seems rare that they give something in terms of bars and you need to convert to atm. Atm is also helpful because of the useful conversion 101.325 J/L*atm.

Karishma_1G
Posts: 67
Joined: Fri Sep 28, 2018 12:18 am

### Re: Units

I usually always try to use atm since the most common gas constant is in terms of atm. Additionally, you can use 101.325 J = 1 L x atm to convert between energy and pressure/volume.

Aleeque Marselian 1A
Posts: 60
Joined: Fri Sep 28, 2018 12:24 am

### Re: Units

Try your best to use atm, since the gas constant (R) is in terms of atm.

KHuang1L
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

### Re: Units

The formula sheet has unit conversion equations to get to J.

Megan_Ervin_1F
Posts: 78
Joined: Fri Sep 28, 2018 12:18 am

### Re: Units

Does anyone have a good summary of all the equations we should know? some of them aren't on the equation sheet...

Timothy_Yueh_4L
Posts: 57
Joined: Fri Sep 28, 2018 12:28 am

### Re: Units

Best bet is to use atm for pressure but I'm sure the equation sheet will give us conversions between different pressure values.