A student investigates the displacement reactions of the Group 7 elements.
They add aqueous chlorine (Cl2\text{Cl}_2Cl2) to separate test tubes containing solutions of sodium chloride (NaCl\text{NaCl}NaCl), sodium bromide (NaBr\text{NaBr}NaBr), and sodium iodide (NaI\text{NaI}NaI).
An organic solvent, cyclohexane, is then added to each test tube. The mixtures are shaken and allowed to settle into two distinct layers.
Table 1 shows the observations for the top cyclohexane layer.
Table 1
| Sodium halide solution | Colour of cyclohexane layer after adding chlorine and shaking |
|---|---|
| Sodium chloride | Pale green |
| Sodium bromide | Orange |
| Sodium iodide | Violet |
Explain the observations shown in Table 1.
Your response should include ionic equations for any reactions that occur and account for the trend in reactivity of the Group 7 elements.
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.