1) H2SO4 -> H2SH2SO4 + 8H^+ + 8e^- -> H2S + 4H2O
2) H2S -> S2H2S -> 3S + 2H2
3) S -> Na2S2O3S + 2Na2S2O3 -> 3S + 2Na2S2O4
4) Na2S2O3 -> Na2S4O62Na2S2O3 -> Na2S4O6 + Na2SO3
1) H2SO4 -> H2S
H2SO4 + 8H^+ + 8e^- -> H2S + 4H2O
2) H2S -> S
2H2S -> 3S + 2H2
3) S -> Na2S2O3
S + 2Na2S2O3 -> 3S + 2Na2S2O4
4) Na2S2O3 -> Na2S4O6
2Na2S2O3 -> Na2S4O6 + Na2SO3