Chapter 18, Problem 99AP

. Balance each of the following half-reactions.

a. ${\text{I}}^{-}\left(aq\right)\to {\text{I}}_{\text{2}}\left(s\right)$   b. ${\text{O}}_{\text{2}}\left(g\right)\to {\text{O}}^{2–}\left(s\right)$   c. ${\text{P}}_4\left(s\right)\to {\text{P}}^{3-}\left(s\right)$   d. ${\text{Cl}}_{\text{2}}\left(\text{g}\right)\to {\text{Cl}}^{-}\left(aq\right)$