Question

Iron (III) catalyses the reaction between iodide and persulphate ions, in which
A. \(\text{Fe}^{3+}\) oxidises the iodide ion
B. \(\text{Fe}^{3+}\) oxidises the persulphate ion
C. \(\text{Fe}^{2+}\) reduces the iodide ion
D. \(\text{Fe}^{2+}\) reduces the persulphate ion
Choose the most appropriate answer from the options given below:

• A. B and C only
• B. B only
• C. A only
• D. A and D only

Answer 1

The Correct Option is D

The reaction proceeds as follows:
\[2\text{Fe}^{3+} + 2\text{I}^- \rightarrow 2\text{Fe}^{2+} + \text{I}_2\]
\[2\text{Fe}^{2+} + \text{S}_2\text{O}_8^{2-} \rightarrow 2\text{Fe}^{3+} + 2\text{SO}_4^{2-}\]
In this reaction:
Fe$^{3+}$ oxidizes I$^-$ to I$_2$ and converts itself to Fe$^{2+}$.
Fe$^{2+}$ reduces S$_2$O$_8^{2-}$ to SO$_4^{2-}$ and converts itself back to Fe$^{3+}$