JAMB - Chemistry (2005 - No. 12)
The decolourization of purple colour of tetraoxomanganate (VII) ion is a test for
alkenes
alkanols
alkanals
alkanes
Explication
Alkenes decolourize potassium permanganate (KMnO\(_4\)) solution, a reaction used as a test for unsaturation, with the purple color of KMnO\(_4\) changing to a brown precipitate or a colorless solution depending on reaction conditions.