## Calculating entropy

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

Peter Nguyen 2I
Posts: 61
Joined: Fri Sep 28, 2018 12:29 am

### Calculating entropy

Why do we calculate entropy for volume change and temperature change independently?

Jim Brown 14B Lec1
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Re: Calculating entropy

If there's a change in pressure/volume, the entropy is dependent on Temperature. If there's a change in Temperature, the entropy is dependent on volume. You've gotta do one before the other or else there's just no calculation (that a 14B student knows how to do, idk about actual chemists).

Ariel Cheng 2I
Posts: 67
Joined: Fri Sep 28, 2018 12:29 am

### Re: Calculating entropy

When we calculate the two independently, we are essentially splitting it up into steps which is allowed since entropy is a state function. First we change the volume and then we change the temperature to reach the final form.

Jonny Schindler 1A
Posts: 30
Joined: Fri Sep 28, 2018 12:20 am

### Re: Calculating entropy

Once you do each, just add the two to get the total change in entropy

Mark 1D
Posts: 63
Joined: Fri Sep 28, 2018 12:18 am

### Re: Calculating entropy

we isolate the two changes in entrophy and then add together