Question

Add 2.0 mL of dichloromethane to each of four clean, dry, labeled 13 x 100-mm test tubes. To each test tube, add 0.50 mL of a different aromatic hydrocarbon--toluene, ethylbenzene, isopropylbenzene, or t-butylbenzene--and swirl to mix. Carefully add 0.50 mL of freshly prepared 1.0 M bromine in dichloromethane to each test tube, then stopper and shake it.

Questions:

1) Arrange the four hydrocarbons in order of their reactivity toward bromine, most reactive first, and compare your results with your prediction

2) Write a balanced equation for each reaction (assuming monobromination), and give the structure of the free-radical intermediate.

3) Arrange the free radicals in order of stability and explain their relative stabilities.

4) Write a complete mechanism for the bromination of toulene.

Answer 1