1. Extended Only

Ozone is an oxidant. It can oxidise an iodide ion to iodine.

2I^– + O₃ + 2H⁺ → I₂ + O₂ + H₂O

i) What would you see when ozone is bubbled through aqueous acidified potassium iodide?

[2]

ii) Explain in terms of electron transfer why the change from iodide ions to iodine molecules is oxidation.

[1]

iii) Explain, using your answer to b(ii), why ozone is the oxidising agent in this reaction.

[1]