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Transition metals (A-level only)

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Question 3

Iron(II) ions, Fe2+\text{Fe}^{2+}Fe2+, act as a homogeneous catalyst in the reaction between peroxodisulfate ions (S2O82−\text{S}_2\text{O}_8^{2-}S2​O82−​) and iodide ions (I−\text{I}^-I−). Which of the following equations represents the step in this catalytic mechanism in which iron is reduced?

A

S2O82−+2Fe2+→2SO42−+2Fe3+\text{S}_2\text{O}_8^{2-} + 2\text{Fe}^{2+} \rightarrow 2\text{SO}_4^{2-} + 2\text{Fe}^{3+}S2​O82−​+2Fe2+→2SO42−​+2Fe3+

B

2Fe2++I2→2Fe3++2I−2\text{Fe}^{2+} + \text{I}_2 \rightarrow 2\text{Fe}^{3+} + 2\text{I}^-2Fe2++I2​→2Fe3++2I−

C

2Fe3++2I−→2Fe2++I22\text{Fe}^{3+} + 2\text{I}^- \rightarrow 2\text{Fe}^{2+} + \text{I}_22Fe3++2I−→2Fe2++I2​

D

2SO42−+2Fe3+→S2O82−+2Fe2+2\text{SO}_4^{2-} + 2\text{Fe}^{3+} \rightarrow \text{S}_2\text{O}_8^{2-} + 2\text{Fe}^{2+}2SO42−​+2Fe3+→S2​O82−​+2Fe2+

Markscheme

Transition metals (A-level only) Questions

  1. A Level
  2. /Chemistry
  3. /Transition metals (A-level only)

63 exam-style questions on AQA A Level Chemistry Transition metals (A-level only), covering General properties of transition metals (A-level only), Substitution reactions (A-level only), Shapes of complex ions (A-level only), Formation of coloured ions (A-level only), Variable oxidation states (A-level only), and Catalysts (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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