Question

In the reaction,

\[\ce{MnO^{-1}_4 (aq) + Br^{-1}(aq) -> MnO2(s) + BrO^{-1}_3(aq)}\]

the correct change in oxidation number of the species involved is ______.

Options

• Br⁺⁵ to Be^-1

• Mn⁺⁷ to Mn⁺²

• Mn⁺⁷ to Mn⁺³

• Br^-1 to Be⁺⁵

Answer 1

In the reaction,

\[\ce{MnO^{-1}_4 (aq) + Br^{-1}(aq) -> MnO2(s) + BrO^{-1}_3(aq)}\]

the correct change in oxidation number of the species involved is Br^-1 to Be⁺⁵.

Explanation:

\[\ce{\overset{+7}{Mn}O^{-1}_4 (aq) + Br^{-1} (aq) -> \overset{+4}{Mn}O2 (s) + \overset{+5}{Br}O^{-1}_3 (aq)}\]

In the above reaction, the oxidation number of Mn in \[\ce{MnO^{-1}_4(aq)}\] decreases from +7 to +4 in MnO₂(s), and the oxidation number of Br increase from -1 (in \[\ce{Br- (aq)}\] to +5 (in \[\ce{BrO^{-1}_3(aq)}\]).