# Chlorine water is added to a solution of potassium bromide and then to a separate solution of potassium iodide. Describe what is observed in each reaction and explain why chlorine is able to displace both bromine and iodide from these solutions.

> Cambridge International IGCSE Chemistry (0620) — 8.3 Group VII properties · Describe and Explain · 4 marks

## Mark scheme (4 marks)

1. Chlorine water turns the potassium bromide solution orange/brown (bromine is displaced/produced)
2. Chlorine water turns the potassium iodide solution brown/dark brown (iodine is displaced/produced)
3. Chlorine is more reactive than bromine and iodine
4. A more reactive halogen displaces a less reactive halogen from a solution of its salt / chlorine atoms gain electrons more easily than bromine or iodine atoms

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