Electrophilic substitution of benzeneEdexcel International A Level Chemistry: Mind map

Exam questions on Electrophilic substitution of benzene

1. Benzene is warmed with a mixture of concentrated nitric acid and concentrated sulfuric acid at 50 °C to make nitrobenzene, C₆H₅NO₂.
   Write an equation for the formation of the electrophile in this reaction and explain why the temperature is kept at or below 55 °C.2 marks
2. Benzene reacts with bromine to form bromobenzene, C₆H₅Br, in the presence of anhydrous iron(III) bromide, FeBr₃, as a catalyst.
   Write the overall equation for the reaction, and an equation to show that the catalyst is regenerated.2 marks
3. Benzene is heated under reflux with ethanoyl chloride, CH₃COCl, in the presence of anhydrous aluminium chloride to make phenylethanone, C₆H₅COCH₃.
   Give an equation for the formation of the electrophile, the overall equation for the reaction, and one reason why the aluminium chloride must be anhydrous.3 marks