A student adds chlorine water to colourless potassium iodide solution. The solution turns brown.
Write the ionic equation for this reaction.
Explain why potassium ions are not included in the ionic equation.
Complete the half equation for the change that happens to the iodide ions. 2I−→\mathrm{2I^{-}} \rightarrow2I−→ ........
Explain, in terms of electrons, which substance is oxidised and which substance is reduced in this reaction.
Explain why this reaction is described as a redox reaction.
41 exam-style questions on Edexcel GCSE Chemistry 7.2 Group 7, covering 7.2.1 Physical properties of the halogens, 7.2.2 Reactions of the halogens, 7.2.3 Relative reactivity and displacement reactions of the halogens, and 7.2.4 Halogen displacement as a redox reaction. Each one has a worked solution and a mark scheme showing where the marks go.