Chapter 4, Problem 41E

Balance each of the following equations according to the half-reaction method:

(a) ${\text{MnO}}_4{}^{-}\left(aq\right)+{\text{NO}}_2{}^{-}\left(aq\right)\to {\text{MnO}}_2\left(s\right)+{\text{NO}}_3{}^{-}\left(aq\right)$ (in base)

(b) ${\text{MnO}}_4{}^{2-}\left(aq\right)\to {\text{MnO}}_4{}^{2-}\left(aq\right)+{\text{MnO}}_2\left(s\right)$ (in base)

(c) ${\text{Br}}_2\left(l\right)+{\text{SO}}_2\left(g\right)\to {\text{Br}}^{-}\left(aq\right)+{\text{SO}}_4{}^{2-}\left(aq\right)$ (in acid)