converting from pressure to concentration

[Vanessa Reyes_1K]

When using the formula PV=nRT t convert between partial pressure and concentration, what is used for R? Is it a constant or should it be given in the problem?

[Sophia Diaz - Dis 1B]

R is a constant that I'm pretty sure will be given to you on an equations list when we take exams. You just have to be aware of which R you use since it changes depending on what you're using. Meaning, R = 0.08206 when we are using Liters and atm (which is what we are doing now), but R = 8.314 when we are using Joules.

[Steven Garcia 1H]

I noticed in a lot of the textbook example R was equal to 8.314 x 10^-2 L^- mol^- bar^- K^-

It has different variations in which it can be written depending on the desired units you need to cancel. I'm confident that the constant value will be provided on any exams.

[uhedlund]

It is a constant that will probably be included in the equations list for tests.

[Srikar_Ramshetty 1K]

R is constant but has many values. The 2 common values are R = 0.0821 L·atm/mol·K or R = 8.3145 J/mol·K. It is important to know the difference because the units are different. At the moment we are working with the first one where atm = atmospheres.

Hope that helps!