write the oxidation and reduction half-reactions for the S2O3 2- /H+ reaction.
The Correct Answer and Explanation is:
In the reaction involving thiosulfate (S2O3²⁻) and hydrogen ions (H⁺), we can write the oxidation and reduction half-reactions separately. The reaction typically occurs in an acidic solution and is often associated with redox processes such as the reduction of thiosulfate to elemental sulfur or sulfite. Below is a breakdown of the half-reactions.
Oxidation Half-Reaction:
In the oxidation half-reaction, thiosulfate (S2O3²⁻) loses electrons and undergoes oxidation to form sulfite (SO3²⁻) or elemental sulfur.
Oxidation of thiosulfate to sulfite:S2O32−→SO32−+e−\text{S}_2\text{O}_3^{2-} \rightarrow \text{SO}_3^{2-} + \text{e}^-S2O32−→SO32−+e−
In this half-reaction, one of the sulfur atoms in the thiosulfate ion is oxidized, resulting in the formation of sulfite.
Oxidation of thiosulfate to elemental sulfur:S2O32−→S+SO32−+2e−\text{S}_2\text{O}_3^{2-} \rightarrow \text{S} + \text{SO}_3^{2-} + 2e^-S2O32−→S+SO32−+2e−
In this case, thiosulfate is oxidized, leading to the formation of elemental sulfur and sulfite, while two electrons are lost.
Reduction Half-Reaction:
In the reduction half-reaction, hydrogen ions (H⁺) are reduced to form hydrogen gas (H2).2H++2e−→H22H^+ + 2e^- \rightarrow H_22H++2e−→H2
This half-reaction shows that two hydrogen ions gain two electrons to form hydrogen gas.
Overall Reaction:
When these half-reactions are combined, we get a balanced redox reaction that reflects both the oxidation of thiosulfate and the reduction of hydrogen ions:S2O32−+2H+→S+SO32−+H2\text{S}_2\text{O}_3^{2-} + 2H^+ \rightarrow \text{S} + \text{SO}_3^{2-} + H_2S2O32−+2H+→S+SO32−+H2
In this reaction, thiosulfate is oxidized to sulfur and sulfite, while hydrogen ions are reduced to hydrogen gas.
Summary:
- The oxidation half-reaction involves the loss of electrons by thiosulfate (S2O3²⁻).
- The reduction half-reaction involves the gain of electrons by hydrogen ions (H⁺) to form hydrogen gas (H2).
- The overall redox reaction involves both the oxidation of thiosulfate and the reduction of hydrogen ions.
