Chapter 17, Problem 6E

Balance the following in acidic solution:

(a) ${\text{H}}_2{\text{O}}_2+{\text{Sn}}^{2+}\to {\text{H}}_2\text{O}+{\text{Sn}}^{4+}$

(b) ${\text{PbO}}_2+\text{Hg}\to {\text{Hg}}_2{}^{2+}+{\text{Pb}}^{2+}$

(c) $\text{Al}+{\text{Cr}}_2{\text{O}}_7{}^{2-}\to {\text{Al}}^{3+}+{\text{Cr}}^{3+}$