## Entropy for Changes in Pressure

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

reginacabanban1I
Posts: 14
Joined: Fri Sep 25, 2015 3:00 am

### Entropy for Changes in Pressure

Why is it for dS in calculations for changes in temperature and volume the final state is always in the numerator of the natural log function {ie. ln(V2/V1) or ln (T2/T1)}
but for pressure the equation is dS = nRln(P1/P2)?

104422816
Posts: 17
Joined: Fri Sep 25, 2015 3:00 am

### Re: Entropy for Changes in Pressure

Because of the way the log function ln(t2)-ln(t1) = ln(t2/t1) which is final-initial and since this is thermodynamics, that is what you would be looking for!