Chapter 16, Problem 64E

Classify each half-reaction occurring in acidic aqueous solution as an oxidation or a reduction and balance the half-reaction.

a. $\text{S}(s)\to {\text{H}}_{\text{2}}\text{s}(g)$

b. ${\text{S}}_2{\text{O}}_8^{2-}(aq)\to 2{\text{SO}}_4^{2-}(aq)$

c. ${\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}^{\text{2-}}(aq)\to {\text{Cr}}^{3+}(aq)$

d. $\text{NO}(g)\to {\text{NO}}_3^{-}(aq)$