5 x 1 hour lessons

In this module, you’ll study the structure, stability, and reactivity of aromatic compounds, starting with benzene. You’ll explore how its bonding and delocalised electron system differ from alkenes, and why it undergoes electrophilic substitution rather than addition. You'll learn how to nitrate benzene, as well as how halogen carriers allow reactions with halogens or acyl groups.

You'll then move on to phenol, examining how its structure affects its acidity and reactivity compared to both alcohols and benzene. You'll learn the mechanisms of phenol reactions with bromine and nitric acid, and understand why these reactions differ from those of benzene.

Finally, you'll study azo dyes, learning how they’re synthesised through diazonium salt formation and coupling reactions. This links organic chemistry to industrial and applied contexts such as dyes and indicators, helping you understand how structure influences colour and stability.

By the end of this module, you’ll be able to:

• Describe the bonding and delocalisation in benzene

• Explain why benzene undergoes substitution rather than addition

• Outline electrophilic substitution reactions including nitration and Friedel–Crafts reactions

• Compare the acidity and reactivity of phenol to alcohols and benzene

• Predict and explain the reactions of phenol 

• Describe the formation of diazonium salts and how azo dyes are synthesised

• Relate structure to colour in azo compounds