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Difference between equations

Posted: Wed Feb 12, 2020 11:48 am
by Rita Chen 1B
When would I use nRln(V2/V1) and when would i use nCpln(T2/T1)? If the pressure is constant and the volume changes, the temperature changes too, so shouldn't both equations be able to be used?

Re: Difference between equations

Posted: Wed Feb 12, 2020 12:08 pm
by Daniela Shatzki 2E
I think generally either both pressure and temperature will be constant resulting only in a change in volume or pressure and volume would be constant resulting in only a change in temperature. If there is a change in volume use nRln(V2/V1), if there is a change in temperature use nCln(T2/T1).

Re: Difference between equations

Posted: Wed Feb 12, 2020 1:14 pm
by Robert Tran 1B
nRln(V2/V1) only works when the temperature is constant because it is derived from the equation (delta)S = q/T, which assumes that temperature is constant.