HW1 solutions

Dear class-

The solutions to HW1 are now posted on the course website.

Cheers,
MSS

HW 1 pickup

Hi everyone,

If you would like to pick up your graded first homework before Thursday class, I will be available in my office (Chemistry 3219) from 3-5 PM tomorrow (Wednesday).

Sunyia

Problem 5 on HW2

Dear class,

At some point in this problem it asks you to prove that DeltaS(Ts) = 0. One approach would be to go back to the derivation for the free energy of folding with temperature that you did in HW1, where you had explicit expressions for DeltaS and DeltaH. Another approach might be to use a thermodynamic identity that you learned in your ChE110 classes. Hint: if you know G(T,P) then what is (dG/dT)_P, by definition?

Cheers,
MSS

Question

I was reading my Biochem book and it states that a closed system exchanges energy, but not matter. I though you said the opposite in class. Also, for today's lecture, I was confused on where the lecture is taking us. Are we studying the probability of empty sites that will later translate to sites on enzymes or some other typing of bonding in the cell?

Closed systems are those that can exchange energy, but not mass. Isolated systems are those that exchange neither.

The example worked in class was just a simple case to illustrate the properties of Boltzmann probabilities. We will not connect this specific example to any biomolecular process; however, the final, general equations that we arrived at, namely the connection between state probabilities and free energies, will be used quite extensively.

HW1, question 4b

Dear class,

There is a typo in part b of question 4 on the homework. It should say that the transfer free energy is N * (0.2 kcal/mol) and not N * (0.1 kcal/mol). An updated HW is posted online. Sorry for the confusion.

Cheers,
MSS

ChE170 logistics

Dear class,

Just a reminder from the syllabus: your current reading assignment is Chapters 1-2 in ECB3. Our first quiz will be next Thursday, 9/30, at the start of class, and it will cover this material.

Below I am also posting the complete office hours schedule for this quarter:

Mondays 11am-12pm, MSS - Eng. II 3321
Tuesdays 3-4pm, Sunyia - Eng. II 3201
Wednesdays 10-11am, MSS - Eng. II 3321
Fridays 12-1pm, Sunyia - Eng. II 3201

Cheers,
MSS

TA Office Hours this Quarter

My ChE 170 office hours this quarter will be in EngII, Room 3201, Tuesdays 3-4 PM, and Friday 12-1 PM, starting next week (9/28)! This room is the ChemE TA room, and it's on the third floor outside by one of the the stairs.

Sunyia