## Change in temp vs Change in volume equations

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

Nickolas Manipud 1C
Posts: 60
Joined: Fri Sep 29, 2017 7:07 am

### Change in temp vs Change in volume equations

For these equations, $\Delta S=nCln(T2/T1), \Delta S=nRln(V2/V1)$, why is there a C for one equation and an R for the other

JennyCKim1J
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am

### Re: Change in temp vs Change in volume equations

I think C is for constant volume, which is 3/2R, and R is just gas constant? Cv, constant volume, cannot be used for the second equation b/c volume is changing (V1 -> V2).

Sarah Sharma 2J
Posts: 33
Joined: Fri Sep 29, 2017 7:05 am

### Re: Change in temp vs Change in volume equations

To add to the comment above, the C can imply either constant volume or pressure, due to the temperature change, either can be held constant. Constant pressure denoted (Cp) would be 5/2 R and Constant Volume would be denoted as (Cv) 3/2R.