PS9

Class,

PS9 is online in case you did not get a paper copy in class. Also, there is a correction in problem 4. Where it refers to "problem 5" it should read instead "problem 3".

MSS

Office hours tomorrow

Dear class,

I will hold office hours tomorrow immediately after our class, at 1:30pm.

MSS

TA Office hour

Due to the change of PS due date, I think I need to change TA office hour to Monday after class, 3:00-4:00.

Is it good for you? 

Hint for 2.2 on midterm

You are looking for the variation of T with V in a certain kind of process. Thus, you might want to consider a derivative of the form (dT/dV).
MSS

Extra office hours

If there are further questions about PS6, I will be available in my office from 3-4pm today (11/6) to answer questions.
MSS

Correction to today's lecture

I inadvertently omitted a part of an equation derived today in class.

Recall that we had for the pure-component chemical potential:

d(mu/T)/dT = -h / T^2

If we assume h is constant with temperature, we can integrate from Tm to T, where Tm is the pure melting temperature, to get:

mu(T)/T - mu(Tm)/Tm = h * (1/T - 1/Tm)

Or, rearranging

mu(T) = h * (1 - T/Tm) + mu(Tm) * (T/Tm)

In class, I left off the rightmost term. When we apply this equation to both the pure liquid and crystal and take the difference, we get:

mu_L(Tm) - mu_X(Tm) = (h_L - h_X) * (1 - T/Tm) + [mu_L(Tm) - mu_X(Tm)] * (T/Tm)

However, mu_L(Tm) = mu_X(Tm) by the conditions for phase equilibrium at Tm, so the rightmost term vanishes.

MSS