Verification of alkenes with bromine
Solution of bromine in carbon tetrachloride T C 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
cyclohexene F Xn R 11-22 S 9-16-23-33
toluene F 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.
- Safety goggles! Exhaust hood.
- One adds approx. 1 ml toluene and 2 - 3 drops of the alkene to the test tube.
- Then one adds three drops of the bromine solution and sways the test tube back and forth.
- In a short time the reddish coloring of the bromine becomes weaker, eventually the solution becomes transparent.
- The reaction mixture is to be disposed of as halogene-free organic waste.
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