Identify a specific topic from Chapter 11 (or from C105 that applies to Chapter 11) that you are having a bit of difficulty with. Include your thoughts on "why" you are having difficulty with that topic. 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. She thinks that it is because she has difficulty visualizing in three dimensions. 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. Maybe you can take an apple and actually cut it in half three times to help you visualize this.
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. I know that we have been talking about this on the molecular level also, but I do not understand how temperature is related to the external pressure.
(Now the next person explain this to me and then list your own issue)
So jumping into C106 after a two year break from C105 is difficult. Therefore chapter 11 is not going as well as I had hoped. The main concept that I am having trouble with is that of inter-molecular forces between molecules. I think this mostly has to do with me not understanding how to determine the polarity and geometry of the molecule. Understanding how to determine the IMF helps then relate to the boiling point and vapor pressures later on in the chapter. So I feel like I am behind because of the break I took between classes, so any help would be appreciated.
ReplyDeleteThank you.
as you said abigail, determining the molecular geometry is essential in determining polarity of a molecule. First i figure out the moleculare geometry, if the geometry is symmetrical then it is non polar, meaning it is dispersion force. And as for hydrogen bonding, if there is a H bonded to either N,O,F, then it is hydrogen bonding. anyway if you have any further questions i would be more than willing to meet up and show you how to draw out some electron geometry and molecular geometry and how i do it from there. it is kind of hard to write out since it is a visual process. Shoot me an email on oncourse if you are intereste.
ReplyDeleteAs for me, i am having trouble with some of the classius clayperon equations and when to use each one.
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ReplyDeleteI am personally having the same problem with the equations. Therefore I don't think I can be much help with that . The only advice that I can give is to first write down all you have been given in the problem, then identify what you need, and lastly decide the process to solve for what you need. When deciding the process look for how many points are given as in multiple temperatures. If you're given two points then you know to use the third equation. If you do not have 2 points then it's up to you to determine if it's one of the other two equations. Considering I have the same problem and when to use each one I'd like to see what someone else has to say.
ReplyDeleteThanks for your responses!
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