Testing for unsaturation with bromine on a microscale

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Try this class experiment to prepare elemental bromine and use it to test for unsaturation in organic compounds. Includes kit list and safety instructions.

In this practical, students use reverse disproportionation to produce a source of bromine from bromate ions, bromide ions and acid. They extract the bromine into hexane in a plastic pipette and decant the resulting solution into a well-plate.

Students can then test for unsaturated hydrocarbons, mixing the bromine solution with organic compounds such as cyclohexane, cyclohexene and limonene. Unsaturated compounds rapidly decolourise the bromine.

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