The document outlines the balanced chemical reactions involving thiosulfate and protons, resulting in the formation of elemental sulfur, sulfur trioxide, and water. It details the oxidation and reduction half-reactions, indicating that 8 electrons are transferred in both the balanced oxidation and reduction half-reactions, as well as in the overall reaction. The final balanced reaction combines these components into a single equation.

1. Write the balanced reaction where thiosulfate and protons are the only reactants; and water,
elemental sulfur, sulfur trioxide, and water are the only products. (Hint: this easier if you start
with the balanced half-reactions). How many electrons are transferred in the balanced oxidation
half reaction? How many electrons are transferred in the balanced reduction half reaction? How
many electrons are transferred in the overall reaction?
Solution
S2O3^2- (aq) + H^+ -------------> S + SO3 + H2O
Oxidation half
reaction                                    Â
                                       Â
  reduction half reaction
S2O3^2- (aq) ------------>
2SO3(g)Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
                       S2O3^2- ------------> 2S
S2O3^2- (aq)+3H2O ------------>
2SO3(g)Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
     S2O3^2- ------------> 2S+ 3H2O
S2O3^2- (aq)+3H2O ------------> 2SO3(g)+ 6H^+(aq)
                     S2O3^2- + 6H^+ (aq) ------------> 2S+ 3H2O
S2O3^2- (aq)+3H2O ------------> 2SO3(g)+ 6H^+(aq) + 8e^- Â Â Â Â Â Â Â Â S2O3^2- +
6H^+ (aq) +4e^- ------------> 2S+ 3H2O
S2O3^2- (aq)+3H2O ------------> 2SO3(g)+ 6H^+(aq) + 8e^- Â Â Â Â Â Â Â ( 8 electrons are
transferred)
2S2O3^2- + 12H^+ (aq) +8e^- ------------> 4S+
6H2OÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ( 8 electrons are transferred)
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2. 3S2O3^2- (aq) +6H^+ (aq) --------------> 2So3(g) + 4S +3H2O overall reaction