My Notes
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A guided inquiry activity for students to build the MO diagram for HF based on energetic and symmetry considerations. Students then compare their model to a standard MO diagram and examine what additional information a MO diagram conveys that the Lewis structure does not.
| Attachment | Size |
|---|---|
| Heteronuclear MO Activity | 134.84 KB |
1. Construct a heteronuclear, diatomic MO diagram based on energy and symmetry considerations
2. Analyze a heteronuclear, diatomic MO diagram to describe bonding and molecular structure
None
The first page serves as a review of homonuclear diatomic structure before beginning on heteronuclear diatomic structure.
Students may need guidance on 3b, but it is okay if they have small mistakes in the drawing the MO for HF. Question 4 asks them to compare theirs to the standard (they never notice that the "answer' is on the next page when they first draw theirs). Question 4 is a chance to look at their diagram and figure out why theirs looks different and why they potentially need to change their drawing.
Evaluation
Recently my classes have been very small (5 student last year, 3 students this year). I have not done quantitative or qualitative assessment of how this guided inquiry activity compares to my prior classroom activity (interactive questioning powerpoint to build MO as a class.) Anecdotally, students seem more engaged and more willing to ask questions when they are unsure with this format.
This is a nice walkthough the MO diagram of HF Andrea. I had just finished going through this in class this year, but will likely adopt and adapt your LO for next year. One thing I did include this year that might be a nice addition for folks is some small computational aspect to talk about. Adam Johnson has me hooked on thinking about NBOs
I ran this on Gauss View using B3LYP-3-21G+/* for no particular reason.
0 electrons in an anti-bonding orbital that is 78.01% H 1s and 21.99% F( 20.54% 2s and 79.46% 2p) at 0.06 Hartrees
4 electrons in degenerate non-bonding orbitals that are 100% F 2p at -0.43 Hartrees
2 electrons in a bonding orbital that is 21.99% H 1s and 78.01% F (20.54% 2s and 79.46% 2p) at -0.57 Hartrees
2 electrons in a non-bonding orbital that is 100% F (79.48% 2s and 20.52% 2p) at -1.24 Hartrees
2 electrons in a non-bonding orbital that is 100% F 1s at -24.61 Hartrees