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+I22\text{NaI} + \text{Cl}_2 \rightarrow 2\text{NaCl} + \text{I}_22NaI+Cl2→2NaCl+I2
The reaction mixture changes from colourless to a distinct brown colour.
State the name of the substance responsible for this brown colour.
Practise Edexcel GCSE Chemistry Group 7 with exam-style questions for Foundation and Higher tier. 87 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.