A student adds chlorine water to a colourless solution of sodium iodide. A displacement reaction takes place according to the following equation:
2NaI+Cl2→2NaCl+I2 2\text{NaI} + \text{Cl}_2 \rightarrow 2\text{NaCl} + \text{I}_2 2NaI+Cl2→2NaCl+I2The reaction mixture changes from colourless to a distinct brown colour.
State the name of the substance responsible for this brown colour.
106 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.