Outline the procedure you used to distinguish between an alkene and the corresponding alkane (3 marks)
In a darkened lab (absence of UV light), a test tube is filled with 5ml of cyclohexane and a second test tube is filled with 5ml of cyclohexene.
3 drops of (brown) bromine water is added to each tube. A stopper is placed on top, and the test tubes are both shaken.
The test tube containing cyclohexane will remain a brownish colour, due to no reaction taking place. The test tube containing cyclohexene will go from brownish to colourless.
C6H10 (L) + Br2 (L) --> C6H10Br2 (L)
The double bond within cyclohexene is broken, thus both bromine atoms may combine to the carbons atoms that shared the C=C double bond.