(2) _(2)(O)_(2)+(I)^-+(H)^+ →-|||-(4) FeCl3+H2S- →-|||-(6) +HN(O)_(3) (浓)→-|||-(8) _(2)+(H)_(2)S(O)_(3)+(H)_(2)O →-|||-(10) _(2)(S)_(2)(O)_(3)+(Cl)_(2)+(H)_(2)O-|||-((12) ({S)_(2)(O)_(8)}^2-+(S)^2-+(OH)^- ___→