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Checking Oxygen in a Sulfite Conversion Model 4 questions
Checking Oxygen in a Sulfite Conversion Model
Base your answers on the information provided and your knowledge of chemistry. Use the 2025 Chemistry Reference Tables as needed.
A class models dissolved sulfite, SO32-, changing to sulfate, SO42-, when oxygen is present. It uses the balanced model equation and assigns oxygen an oxidation number of −2 in both ions. In O2 the oxidation number is 0.
2SO32-(aq) + O2(g) → 2SO42-(aq)
Question 1
Calculate sulfur’s oxidation number in each ion. Show how the ion charge enters the calculation.
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Question 2
Which description follows from the sulfur change?
- Sulfur is oxidized because its oxidation number increases.
- Sulfur is reduced because its oxidation number increases.
- Sulfur is oxidized because its oxidation number decreases.
- Sulfur has no change in oxidation number.
A student claims oxygen cannot be reduced in this reaction because the sulfate ion has the same overall charge as sulfite.
Question 3
Use the oxidation numbers of oxygen in O₂ and in sulfate to evaluate the claim.
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Question 4
How many electrons are accounted for by the oxidation of the two sulfur atoms in the equation? Explain why the two oxygen atoms from O₂ can account for the same total.
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