Question

Which of the following can not act as an oxidising agent?

• A. MnO₄^-
• B. SO₂^-
• C. N₃^-
• D. BrO₃^-

Answer 1

The Correct Option is C

To identify the compound that does not function as an oxidizing agent, one must first define an oxidizing agent. An oxidizing agent, also termed an oxidant, is a substance capable of oxidizing other substances. This occurs when the oxidizing agent accepts electrons from them. Consequently, an effective oxidizing agent readily gains electrons and undergoes reduction in the process.

Let's examine each option:

• MnO₄^- (Permanganate Ion): Permanganate is a potent oxidizing agent, particularly in acidic conditions. It can be reduced from Mn⁷⁺ to Mn²⁺ (or MnO₂), signifying a substantial electron gain. Therefore, MnO₄^- functions as an oxidizing agent.
• SO₂^- (Sulfur Dioxide Ion): This representation is ambiguous, as SO₂ is typically a gas and not commonly encountered as an ion in this specific form. While SO₂ can act as both a reducing and oxidizing agent under varying conditions, its ionized species, SO₂^2-, primarily acts as a reducing agent. However, within the context of this question's analysis, SO₂'s oxidizing capacity must be considered.
• N₃^- (Azide Ion): The azide ion generally does not act as an oxidizing agent. It is more frequently involved in nucleophilic reactions or found in explosive compounds due to its inherent instability. As such, it does not typically perform the role of an oxidizing agent.
• BrO₃^- (Bromate Ion): Analogous to MnO₄^-, BrO₃^- is recognized as a strong oxidizing agent. It can be reduced from Br⁵⁺ to Br^-, thereby accepting electrons.

Based on this evaluation, the azide ion (N₃^-) is identified as the substance that does not typically act as an oxidizing agent.

Conclusion: The substance that cannot act as an oxidizing agent is N₃^-.