pKa prediction for oxyacids (oxoacids?)

Submitted by Adam Johnson / Harvey Mudd College on Wed, 10/01/2008 - 11:56

I have in my notes from 9 years ago, this handy equation for prediction of pKa's for oxyacids.  I was using Huheey at the time, and the equation isn't there.  In fact, I can't find it ANYWHERE.  I am certain that I did not develop this equation.... Does anyone recognize it?  Where is it from?  And which electronegativity values does it use?

 

pKa ~ 10.5 -5n - (chi)X

for

(HO)mX(O)n;  chi is the electronegativity of the central atom X, n is the number of oxos.

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MO diagrams for NO and CO

Submitted by Nancy Williams / Scripps College, Pitzer College, Claremont McKenna College on Thu, 09/25/2008 - 19:12

OK, so we all love the homonuclear diatomics, and how the 2p sigma is *below* the 2p pi for O2 and F2, almost equal at N2, and above 2p pi for C2, B2, etc.

 CO looks a lot like N2, but it's asymmetric...the 2p sigma is the HOMO. Disturbingly, the gap seems to be *larger* than in N2...why is that?!? Being isoelectronic, it seems like it should be about the same, but there should be *more* contribution from the oxygen orbitals in the *bonding* orbitals since O is more electronegative than C.

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MO
CO
NO
computational chemistry
orbitals

MacGyver problems

Submitted by Adam Johnson / Harvey Mudd College on Tue, 09/23/2008 - 23:38
Story problems are often contrived.  Puns are often unappreciated.  But, if you can't have fun at work, why go to work at all!  I like these kind of problems, since they usually make it clear which students are paying attention and which ones are just memorizing the facts.  You need to internalize the information to answer these types of questions.  Here are some of my faves from our first year course in the equilibrium section.  Please post yours, or better yet, submit it as a learning object!  You can expect to find these on the site shortly under the problem set question section.
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Inorganic TA seeks single crystal compound for undergraduate lab synthesis, non-trivial structure solution, and maybe more.

Submitted by Julia C. / University of California Davis on Sat, 09/20/2008 - 20:38
I am looking for a straightforward synthesis of good single crystals for our Inorganic Chemistry students (juniors and seniors) to make in lab and then use to learn about collecting structural data and solving the single crystal structure using our software. The compound should be safe, stable, and easy to handle. It can be (but doesn't need to be) a molecular compound, and should be more complex than a simple salt. If anyone has ideas, suggestions, or recommendations, I would love to hear them. Thank you!
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What's Your Favorite Lecture?

Submitted by Maggie Geselbracht / Reed College on Wed, 09/17/2008 - 20:40

After introducing my Gen Chem students to the Quantum Mechanical Model of the Atom today and waiting...waiting for that lovely question..."but how does an electron get from one side of the p orbital to the other?", I decided this might be my favorite lecture of the semester.

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Foundational course

Submitted by Tim Herzog / Weber State University on Wed, 09/10/2008 - 16:11

We're revamping our curriculum to include a foundational inorganic course probably in the sophomore year.  I have a couple of questions to those of you who teach this course or are planning such a course.  

1.  What books do you like?  I have struggled to find anything that fits the bill for this type of class.  

2.  Where do you put the course?  Does it usually land in the sophomore year?  We currently have quant and organic, but also need to add a more foundational P-chem and biochem.  Where does it all fit? 

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First day activity

Submitted by Jim Goll / Edgewood College on Wed, 08/27/2008 - 08:45
I wear my VIPEr tatoo on my arm.  I show short segments of the movies Apollo 13 and October Sky and talk about scientific methodology.  As part of this activity the students take a short exra-credit quiz.
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Cool first day activities?

Submitted by Hilary Eppley / DePauw University on Sun, 08/24/2008 - 20:42
Hi everyone, I was wondering what kinds of interesting ways that people kick off the school year/ set the tone for the semester with their students (upper or lower division)? With my lower level students, I've sometimes taken a recent article from a newspaper (an article about a local magnesium fire or the polonium poisoning that happened a couple of years ago, come to mind as examples) and had students come up with 10 inorganic chemistry questions based on the article, to emphasize the importance of asking the right kinds of questions in the class.
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