Sulfur dioxide ($\text{SO}_2$) is a chemical compound that can participate in various reactions, acting as both an oxidizing and a reducing agent depending on the reaction conditions. While the question asks for an "oxidation reaction" of sulfur dioxide (where $\text{SO}_2$ loses electrons and its sulfur oxidation state increases), the provided reference explicitly gives a reaction where $\text{SO}_2$ is reduced.
Reaction of Sulfur Dioxide from the Reference
The specific reaction involving sulfur dioxide mentioned in the provided reference is:
SO₂ + 2 H₂S → 3 S + 2 H₂OAnalysis of the Provided Reaction
In this reaction:
- Sulfur dioxide ($\text{SO}_2$): The oxidation state of sulfur here is +4.
- Hydrogen sulfide ($\text{H}_2\text{S}$): The oxidation state of sulfur here is -2.
- Sulfur ($\text{S}$): The oxidation state of sulfur in its elemental form is 0.
- Water ($\text{H}_2\text{O}$): The oxidation state of oxygen is -2 and hydrogen is +1.
Let's examine the changes in oxidation states:
- Sulfur in $\text{SO}_2$ goes from +4 to 0 (in the product $\text{S}$). This is a decrease in oxidation state, meaning $\text{SO}_2$ is reduced. In this reaction, $\text{SO}_2$ acts as an oxidizing agent.
- Sulfur in $\text{H}_2\text{S}$ goes from -2 to 0 (in the product $\text{S}$). This is an increase in oxidation state, meaning $\text{H}_2\text{S}$ is oxidized. In this reaction, $\text{H}_2\text{S}$ acts as a reducing agent.
Therefore, the reaction provided in the reference (SO₂ + 2 H₂S → 3 S + 2 H₂O) shows a reaction of sulfur dioxide, but it is a reduction reaction for $\text{SO}_2$, not an oxidation reaction.
Sulfur Dioxide Oxidation in Sulfuric Acid Production
The reference also notes that "The sequential oxidation of sulfur dioxide followed by its hydration is used in the production of sulfuric acid." This statement indicates that sulfur dioxide can undergo oxidation, specifically as a step in the industrial process for creating sulfuric acid ($\text{H}_2\text{SO}_4$).
While the exact chemical equation for this oxidation step (where $\text{SO}_2$ is converted to sulfur trioxide, $\text{SO}_3$) is not provided in the reference, this context confirms that sulfur dioxide is capable of being oxidized under different conditions than the reaction with hydrogen sulfide.
Summary Table
Based on the provided reference:
| Reaction/Process | Reactant(s) | Product(s) | Role of $\text{SO}_2$ | Notes |
|---|---|---|---|---|
| Reaction with Hydrogen Sulfide | $\text{SO}_2$, $\text{H}_2\text{S}$ | $\text{S}$, $\text{H}_2\text{O}$ | Reduced | $\text{SO}_2$ acts as an oxidizing agent |
| Sequential process for $\text{H}_2\text{SO}_4$ production | $\text{SO}_2$, (Oxidizing agent) | (Intermediate, then $\text{H}_2\text{SO}_4$) | Oxidized | Specific reaction equation not provided |
In conclusion, the provided reference includes a reaction of sulfur dioxide where it is reduced. It also mentions that sulfur dioxide undergoes oxidation as part of the process to produce sulfuric acid, although the specific reaction equation for this oxidation is not given.
