Value of R
Posted: Mon Feb 03, 2020 6:27 pm
Why does the value of R has to be altered depending on if the problem gives constant volume or constant pressure?
Re: Value of R [ENDORSED]
Posted: Tue Feb 04, 2020 11:58 am
The gas constant is the same, but it does have different units and therefore different values (which are the same after taking units into account).
I think you are referring to Cv and Cp which are different for gases.
As I discussed in class if a gas is heated and its pressure stays constant, then its volume must increase and therefore does work of expansion (which requires energy).
Unlike Cv, where the gas is heated under a constant volume and therefore does no work.
Therefore, Cv and Cp for gases have different values.