Group 7

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An analytical chemist is tasked with establishing the trend in oxidising ability (relative reactivity) of three halogens: chlorine, bromine, and iodine.

They are provided with:

Aqueous solutions of the halogens: chlorine water ( $Cl_2(aq)$ ), bromine water ( $Br_2(aq)$ ), and iodine solution ( $I_2(aq)$ )
Aqueous solutions of their sodium salts: sodium chloride ( $N a C l (a q)$ ), sodium bromide ( $N a B r (a q)$ ), and sodium iodide ( $N a I (a q)$ )
An organic solvent: cyclohexane ( $C_6H_{12}$ )

Describe a systematic experimental procedure the chemist should follow to determine the relative oxidising power of these three halogens, incorporating the use of cyclohexane to make the observations clearer.

In your answer, you should:

explain how the observations, particularly within the organic layer, allow the determination of the trend
write balanced ionic equations for any two of the displacement reactions that occur.

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Group 7 Questions

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.