Post Test: Isomer Problems
This student attempted to draw a straight chain isomer. There really wasn't enought time for the students to accurately draw the isomers in this manner. Problems with determining the units of unsaturation led to the incorrect structure. This was done despite many reminders that isomers are just different connectivities of the same atoms and you could just move a group to another location (such as the OH or the CH3).
This student was correctin in thinking about isomerism. The student moved the location of the methyl group, but did not translate the OH group from the structure on the previous page. This problem probably would have been avoided if the original structure and the isomer question were on the same page.
This problem represents another example where the student was unable to draw a correct isomer because of problems with the carbon atom count, the units of unsaturation, and attempting to draw a straight chain isomer from a complicated ring structure.
This was a very interesting result in which the student drew the mirror image of the original structure.What does this mean? The student did not attempt to draw a straight chain isomer. This may have been an attempt to move some of the bonds, but it did not result in a different structure.
This student was almost correct in drawing the isomer. The locations of the multiple bonds were chaged, and the OH group was moved. The only problems were missing two carbon atoms when drawing the long chain and a misrepresentation of the geometry of the triple bond.
