Balance each of the following equations according to the half-reaction method:
(a) Sn2+(aq) + Cu2+(aq) ? Sn4+(aq) + Cu+(aq)
(b) H2 S(g) + Hg2
2+(aq) ? Hg(l) + S(s) (in acid)
(c) CN-(aq) + ClO2(aq) ? CNO-(aq) + Cl-(aq) (in acid)
(d) Fe2+(aq) + Ce4+(aq) ? Fe3+(aq) + Ce3+(aq)
(e) HBrO(aq) ? Br-(aq) + O2(g) (in acid)