Organic Chemistry 354 Quiz - October 1, 2001

Dr. Sundin

2. At least one of the reactions above can be used as a simple chemical test to tell the difference between cyclohexane and cyclohexene. Select one reaction and then explain how it can serve as a simple chemical test.

Two reaction could be used as a simple chemical test to differentiate between cyclohexane and cyclohexene.

Bromine and carbontetrachloride can be used since the red bromine reacts with colorless cyclohexene to give colorless 1,2-dibromocyclohexane. Bromine does not react with cyclohexane at room temperature and in the dark so the cyclohexane solution becomes red and stays red. One could represent the test as follows:

Dilute basic permanganate can also be used since under basic conditions permanganate reacts with a double bond to give an insoluble black precipitate of MnO2. One could represent the test as follows: (Note that while acid permanganate also reacts, MnO2 is not formed and the colored manganese ions are hard to see.)

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