## R value in equation

Volume: $\Delta S = nR\ln \frac{V_{2}}{V_{1}}$
Temperature: $\Delta S = nC\ln \frac{T_{2}}{T_{1}}$

Mia Navarro 1D
Posts: 52
Joined: Fri Sep 29, 2017 7:04 am

### R value in equation

How do you know which value of the constant R to use for different equations?

Kailey Brodeur 1J
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Joined: Thu Jul 27, 2017 3:00 am

### Re: R value in equation

You have to use the R value with the corresponding units to the other variables you are using. Just make sure the right units are canceling out.

Justin Chu 1G
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### Re: R value in equation

I think generally the R we use more often will contain the units L.atm/mol.K

Meredith Steinberg 2E
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Joined: Thu Jul 13, 2017 3:00 am

### Re: R value in equation

The R value depends on the units you're working with

Joshua Xian 1D
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### Re: R value in equation

Usually when solving for something involving joules/work/energy, you would use 8.314 J/mol•K. If it involves pressure (or if you need to use PV=nRT), you would use the other R constants with pressure units.