## Units

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

805291863
Posts: 100
Joined: Sat Sep 14, 2019 12:16 am

### Units

What is the units for change in entropy? When you take the ln of V2/V1 or T2/T2, does the unit of the volume or temperature remain?

Posts: 103
Joined: Sat Aug 17, 2019 12:18 am

### Re: Units

Entropy is generally calculated in units of J/K. When you take the ln of 2 volumes/temperatures, the units of both will cancel with each other (ln(373 K/323 K)=ln(373/323)). We will be left with units of n (moles) and R (JK^-1mol^-1) which will cancel out to give us J/K.

rabiasumar2E
Posts: 108
Joined: Thu Jul 11, 2019 12:15 am

### Re: Units

The units for change in enthalpy is J/K. And no, the units for temperature will not remain! They'll end up cancelling out.

JChen_2I
Posts: 107
Joined: Fri Aug 09, 2019 12:17 am

### Re: Units

Entropy is always in J/K. The units for the numbers you are finding the natural log of (volume, temperature, pressure) will always end up cancelling out.

BritneyP- 2c
Posts: 101
Joined: Sat Sep 14, 2019 12:15 am

### Re: Units

Entropy is typically J/K, and if you have V2/V1 or T2/T1, the units would cancel out because they are dividing the same units over each other.