Question

The species which does not undergo disproportionation reaction is:

• A. \( \text{ClO}_2^- \)
• B. \( \text{ClO}_4^- \)
• C. \( \text{ClO}_3^- \)
• D. \( \text{ClO}_2 \)

Hint:

Disproportionation reactions typically occur with species that are in intermediate oxidation states and have higher or lower oxidation states they can transition into.

Answer 1

The Correct Option is B

To determine which species does not undergo a disproportionation reaction, we need to understand the concept of disproportionation. A disproportionation reaction is a type of redox reaction in which a single species undergoes both oxidation and reduction, forming two different products.

Let's analyze each given option in the context of chlorine compounds:

• \(\text{ClO}_2^-\): In the disproportionation reaction, this ion can form \(\text{ClO}_3^-\) (oxidation) and \(\text{Cl}^-\) (reduction).
• \(\text{ClO}_2\): This can disproportionate to form higher oxidation state species such as \(\text{ClO}_3^-\) and lower states such as \(\text{Cl}^-\).
• \(\text{ClO}_3^-\): This ion can also undergo disproportionation, forming \(\text{ClO}_4^-\) (oxidation) and \(\text{Cl}^-\) (reduction).
• \(\text{ClO}_4^-\): In this case, the oxidation state of chlorine in \(\text{ClO}_4^-\) is +7, which is its highest possible oxidation state. Because it cannot be oxidized further, it cannot undergo disproportionation.

Conclusion: Thus, the species that does not undergo a disproportionation reaction is \(\text{ClO}_4^-\) because it is already in its highest oxidation state.

Answer 2

Disproportionation reactions involve a species being simultaneously oxidized and reduced to form two different products. Among the given species: - \( \text{ClO}_2^- \) and \( \text{ClO}_3^- \) can undergo disproportionation to form \( \text{ClO}_3^- \) and \( \text{ClO}_2 \), respectively. - \( \text{ClO}_4^- \) does not undergo disproportionation because it is already in its most oxidized state as a chlorine(V) species, and there is no higher oxidation state to form. Thus, the correct answer is \( \text{ClO}_4^- \), which does not undergo disproportionation.