## 9.45 Help.

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

Andrew Uesugi 3I
Posts: 38
Joined: Wed Sep 21, 2016 2:56 pm

### 9.45 Help.

So the question is asking me this:

Calculate the changes in entropy of the surroundings and of the system for (a) the vaporization of 1.00 mol CH4 at is normal boiling point.

So I know the formula is Delta S = - Delta H / T. Why is T = 111.7 K?

Hao 1I
Posts: 26
Joined: Wed Sep 21, 2016 3:00 pm
Been upvoted: 1 time

### Re: 9.45 Help.

The temperature is 111K because that is the boiling point for CH4. The equation for change in entropy for vaporization is equal to the enthalpy of vaporization divided by the boiling point temperature ( delta S = delta H of vaporization / Temp. at boiling point ).