ORGANIC CHEMISTRY Functional Group ID Analysis: Test for Alkenes- Permanganate

Added: 2026-05-16

[00:00:01]Here is 1% potassium permanganate, which will be used to test two compounds in these two test tubes, where the control test tube will contain a saturated hydrocarbon, and the sample test tube will contain an unsaturated hydrocarbon.

[00:00:21]Each test tube gets about 2 ml of solution.

[00:01:17]Now, an equal volume of a dilute 1% potassium permanganate solution is added to each test tube.

[00:01:59]The control test tube remains purple in the bottom layer, indicating a negative test because saturated hydrocarbons do not react with potassium permanganate under these conditions.

[00:02:17]In the sample test tube, the purple color disappears and a brown precipitate forms.

[00:02:22]The positive test confirms the presence of an alkene, which is oxidized to a diol, while the permanganate ion is reduced to manganese dioxide, observed as the brown solid precipitate.