Week 3

Identify a specific topic from Chapter 12 that you are having a bit of difficulty with. The next person to respond should address that problem to the best of their ability and then identify their own issue. 

If you haven't noticed, I will kibitz  just to make sure that we are keeping on track. You might find it useful to go back in after you have posted to read everyone's postings and comments.
So I will start the process off:
"John" says that he is having difficulty with understanding the concept of how an insoluble solute affects the vapor pressure of a solution.

First notice that we are discussing the vapor pressure of a solution not a pure substance as we were in Chapter 11 and we will look at solutions made only from nonvolatile solutes so that it is only the solvent that will be entering the vapor phase.  At a particular temperature, a solvent has a certain amount of energy and there is a subset of the solvent molecules that have enough energy to enter into the vapor phase. When we add a nonvolatile solute and make a solution, those solute particles physically get in the way of the solvent molecules escaping into the vapor phase. Thus a smaller number of solvent molecules can evaporate at any given temperature and the vapor pressure will decrease with the addition of a nonvolatile solute.
A problem that I might have as a student: I am having a little difficulty with understanding the relationship between saturated solutions, supersaturated solutions and dynamic equilibrium.

(Now the next person explain this to me and then list your own issue)

Week 2 Question 2

Identify a specific topic from Chapter 11 (or from C105 that applies to Chapter 11) that you are having a bit of difficulty with. The next person to respond should address that problem to the best of their ability and then identify their own issue.

So I will start the process off:

"Jane" says that she is having difficulty with understanding why there is 1/8th of a corner atom inside a face-centered cubic unit cell. In response to this, I would explain:

A corner atom of a cubic unit cell is cut through by 3 planes (looking at the pictures in your text, page 521 and 522 will help you to see this as I try to explain). For example, a front plane, a side plane and a top plane. Since this "cuts" the atom in half each time, the first time I throw away 1/2 of the atom, leaving 1/2, the second "cut" throws away 1/2 of 1/2 leaving 1/4 and the third "cut" throws away 1/2 of 1/4 leaving 1/8 inside the cubic unit cell. It does not matter whether it is a primitive cubic unit cell, a face-centered cubic unit cell or a body-centered cubic unit cell, a corner atom will always have 1/8 of the atom inside one cubic unit cell.

A problem that I might have as a student: I don't understand how an increase in the external pressure causes the boiling point to increase.

(Now the next person explain this to me and then list your own issue)

Week 2 Question 1

Read the material at the link below: Chapter 13: Effective Learning and Teaching

www.project2061.org/publications/sfaa/online/chap13.htm

Do any of these concepts “speak” to you, either from the learning or teaching point of view? How does it change the way you view learning or teaching?

Week 1

What is your intention for this semester in Chemistry C106? Please don’t put it in terms of a grade, rather share what you hope to get out of the class. (Please post your response as a comment)