Phenol and bromine waterEdexcel International A Level Chemistry: Flashcards
What these 12 flashcards ask
- What is observed when bromine water is added to aqueous phenol?
- What is the white precipitate called?
- What is the equation for phenol with bromine water?
- What type of reaction is it?
- Does benzene react with bromine water?
- What does benzene need to react with bromine?
- Why is phenol more reactive than benzene?
- At which ring positions does substitution occur in phenol?
- What conditions does phenol need to react with bromine?
- Why does a more electron-rich ring react more readily with Br₂?
- How many moles of Br₂ react per mole of phenol?
- How does cyclohexene differ from phenol in its reaction with bromine water?
Exam questions on Phenol and bromine water
- A student adds bromine water to aqueous phenol, C₆H₅OH, at room temperature. The orange colour of the bromine water disappears and a white precipitate forms.Write an equation for the reaction and name its type.2 marks
- Benzene does not react with bromine water. It reacts with bromine only when a catalyst of anhydrous iron(III) bromide is present. Phenol, however, reacts with aqueous bromine at room temperature with no catalyst.Explain why phenol reacts without a catalyst but benzene needs one.2 marks
- A student treats 0.470 g of phenol, C₆H₅OH, with excess bromine water at room temperature and obtains 1.24 g of dry 2,4,6-tribromophenol, C₆H₂Br₃OH. The OH group in phenol is attached directly to the benzene ring.Explain why phenol reacts with bromine water more readily than benzene.3 marks
Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).