Chapter 18, Problem 18.138CP

Interpretation Introduction

Interpretation:

The balanced chemical equation for the conversion of ${\text{Mn}}^{\text{+3}}{\text{to Mn}}^{\text{+2 }}{\text{and MnO}}_{\text{2}}$ if the two half reactions are given, standard potential of the cell and spontaneity of the reaction should be identified.

Concept introduction:

The half-cell with higher standard reduction potential acts as cathode and with lower standard reduction potential acts as anode. The reaction is spontaneous if the value of standard cell potential is more than zero.

Given:

${\text{Mn}}^{\text{+3}}{\text{(aq)+e}}^{-}\to {\text{Mn}}^{\text{+2}}\text{(aq)}$${\text{E}}^{\text{0}}\text{ = 1}\text{.54V}$

${\text{MnO}}_{\text{2}}{\text{(s) + 4H}}^{\text{+}}{\text{(aq) + e}}^{-}\to {\text{Mn}}^{\text{+3}}{\text{(aq) + 2H}}_{\text{2}}\text{O(l)}$${\text{E}}^{\text{0}}\text{ = 0}\text{.95V}$