Sunday, June 19, 2011

Peer instruction: mixing

These slides show questions I used when teaching mixing functions using peer instruction. The slides are in Danish, but I hope you get the idea and there is always Google translate. Any questions, just leave a comment.

Some comments about specific slides:
Slides 1-3 show results from a Molecular Workbench simulation, which you access here.  It is a variation on the simulation I used to illustrate entropy.  If you understand why the gas expands in that example, you also understand why the gasses mix.

Slides 4-10 show results from a Molecular Workbench simulation, which you access here.

Slides 4-5: after two votes there was no clear consensus, but most students likes A "no interactions between molecules".  The second vote came at the end of the first of three back-to-back lectures, so we had a third vote after the break.  There really was intense discussion of this during the break, when most finally settled on B "equal interactions between molecules".   I think A was popular because "ideal solution" conjures up an analogy to "ideal gas", but how can you have a liquid if there are no intermolecular attractions?

Slide 7-8: here is alternated between the simulation and the question a few times.  A better approach would have been to include the question on the web site with the simulation.

Related blog posts
See all posts related to peer instruction here.
Illustrating mixing
Simulations in teaching physical chemistry: thermodynamics and statistical mechanics