Question

Write a balanced half-reaction for the oxidation of manganese ion mn 2 to permanganate ion mno−4 in basic aqueous solution. be sure to add physical state symbols where appropriate.

Answer 1

`Mn^(2+) +8OH^(-) --\ \textgreater \ MnO_(4)^(-) + 4H_(2)O +5e^(-) \\ \\ +2-8=(-6) ----\ \textgreater \ ( -1)+5e^(-)`

Answer 2

Answer : The balanced oxidation half reaction in basic medium will be :

`Mn^(2+)(aq)+8OH^-(aq)\rightarrow MnO_4^-(aq)+4H_2O(l)+5e^-`

Explanation :

Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.

Rules for the balanced chemical equation in basic solution are :

• First we have to write into the two half-reactions.
• Now balance the main atoms in the reaction.
• Now balance the hydrogen and oxygen atoms on both the sides of the reaction.
• If the oxygen atoms are not balanced on both the sides then adding water molecules at that side where the more number of oxygen are present.
• If the hydrogen atoms are not balanced on both the sides then adding hydroxide ion
  `(OH^-)` at that side where the less number of hydrogen are present.
• Now balance the charge.

The balanced oxidation half reaction in basic medium will be :

`Mn^(2+)(aq)+8OH^-(aq)\rightarrow MnO_4^-(aq)+4H_2O(l)+5e^-`