Question 70. In alkaline medium, \mathrm{MnO}_{4}^{-} oxidises \mathrm{I}^{-} to
(1) {\mathrm{IO}}_4^-
(2) \mathrm{IO}^{-}
(3) {\mathrm I}_2
(4) \mathrm{IO}_{3}^{-}
Answer: (4)
Explanation:
In alkaline medium, \mathrm{MnO}_{4}^{-} acts as an oxidising agent.
Iodide ion is oxidised to iodate ion.
The balanced redox reaction is
2{\mathrm{MnO}}_4^-+{\mathrm H}_2\mathrm O+\mathrm I^-\rightarrow2{\mathrm{MnO}}_2+2\mathrm{OH}^-+{\mathrm{IO}}_3^-Hence, the oxidation product of iodide ion is \mathrm{IO}_{3}^{-}.