CAIE A Level Chemistry 9701 · Hydrocarbons
Benzene reacts with bromine in the presence of anhydrous to give bromobenzene. It does not readily undergo addition of bromine across the ring. Explain, in terms of the structure and stability of the benzene ring, why substitution is preferred over addition.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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