Monthly Archives: September 2010

TLC = That’s Lousy Chromatography?

This year I changed one of the solvents in the TLC lab that begins the first semester of Organic Chemistry lab. Instead of dichloromethane, we used ethyl acetate. Ethyl acetate is a less hazardous and more environmentally friendly solvent that dichloromethane. I thought the solvent strength on silica gel would be similar between the two. […]

Could You Repeat the Question Please?

It seems that even the most carefully written question will be misunderstood by a few students. The author of the question usually has a particular result in mind and composes the question in this frame of reference. Students approach the same question from any number of different frames of reference. I imagine some approaches are […]


During the molecular modeling activity I have described before (Model Students, Molecular Mechanics), there is a little moment of discovery. The students make and draw four constitutional isomers with molecular formula C2H5NO2 to answer questions 1 through 9. All the constitutional isomers they have made so far have a double bond. On question 10 they […]