## Conversion of R

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

Naana Boateng 1I
Posts: 58
Joined: Fri Sep 29, 2017 7:07 am

### Conversion of R

When using the Pv=nRt formula, do you represent R as 8.314 or 8.206 x10^-2?

Jessica Jones 2B
Posts: 80
Joined: Fri Sep 29, 2017 7:04 am

### Re: Conversion of R

This would depends on the units you are trying to cancel. If pressure were in atm you would use .0826 so that the units would cancel

Naana Boateng 1I
Posts: 58
Joined: Fri Sep 29, 2017 7:07 am

### Re: Conversion of R

what if pressure was not given to you? Would you use 8.314?

Ivy Lu 1C
Posts: 54
Joined: Thu Jul 27, 2017 3:00 am

### Re: Conversion of R

It still depends on what you're solving for. If you're not given pressure and solving for pressure, then you would use 8.206 x 10-2 L·atm·K-1·mol-1, because that would cancel out so that you get atmospheres for the units of pressure. If you're not given pressure and trying to solve for work, then you use 8.314 J·K-1·mol-1 because that would cancel out so that you get Joules for your units of work.

Angel R Morales Dis1G
Posts: 50
Joined: Sat Jul 22, 2017 3:01 am

### Re: Conversion of R

You would have to see what units you are using or solving for. If you are trying to find joules, you will be using 8.314

Rachel Wang
Posts: 49
Joined: Fri Sep 29, 2017 7:04 am

### Re: Conversion of R

I've found that I generally use 8.314J/mol.K because it cancels out n (mol) and T(K).

AlyssaPeckham1A
Posts: 49
Joined: Fri Sep 29, 2017 7:04 am

### Re: Conversion of R

Check the units behind the constant R to see what needs to cancel out in the problem you are solving.

Phillip Tran
Posts: 54
Joined: Thu Jul 13, 2017 3:00 am

### Re: Conversion of R

youll use 8.314 most of the time but whenver the units are L.atm then you use 8.206