Verification of alkenes with bromine

Chemicals needed

Solution of bromine in carbon tetrachlorideGSGiftig.gif (734 Byte) T GSATZEND.gif (935 Byte) C GSUMWELT.gif (758 Byte)  N   R 23/24/25-26-35-40-48/23-52/53-59    S (1/2)-7/9-23-26-36/37-45-59-61

cyclohexeneGSLEICHT.gif (932 Byte) F GSGESUND.gif (476 Byte) Xn    R 11-22    S 9-16-23-33

tolueneGSLEICHT.gif (932 Byte) F GSGESUND.gif (476 Byte) Xn    R 11-20    S (2)-16-25-29-33

The toluene must be pure (free from alkenes, otherwise the verification is useless). One can, of course, analyze other alkenes and instead of toluene use xylene.

Equipment needed

test tube

Test procedure



Bromine adds to the double bond of cyclohexene forming trans-1,2-dibromocyclohexane. The reaction can be recognized by the disappearence of bromine coloration.


to be added


of own device