Thursday, November 19, 2009

Lecture #23, Wednesday, November 18th

Today we continued discussing Lewis Structures. I started lecture by covering a couple more examples with the surrounding atom or ligand being a halogen, hydrogen, or an OH- group. We then discussed the differences that occur when oxygen or sulfur is the surrounding atom or ligand. Oxygen containing molecules can readily form double bonds, which leads us to multiple resonance structures that can be drawn. Resonance structures of a given molecule will always have the same energy. In addition to resonance structures structures, since some molecules can expand their octet we discussed choosing structures that have different energies and which one would be the "best" Lewis structure. There are two sets of rules you will be responsible for: The octet rule and formal charges. According to our textbook (pg 324-325) "In general, when choosing between alternate Lewis Structures, if it is possible to draw a Lewis Structure where the octet rule is satisfied without using multiple bonds, that structure is preferred."

We will discuss this more on Friday.

Have fun at Mirror Lake on Thurs night, but be sure to come to class on Friday. Last year I had a student make it to class with their sandals still duct taped to their feet :)

GO BUCKS! BEAT BLUE!

No comments:

Post a Comment