The reaction , `M^(2+) (aq) +M(s) hArr 2M^+(aq)` is an example of :

Options

A. Reduction
B. Oxidation
C. Comproportionation
D. Disproportionation

Answer

To solve the question regarding the reaction \( M^{2+} (aq) + M(s) \rightleftharpoons 2M^{+} (aq) \), we need to analyze the changes in oxidation states of the elements involved in the reaction.

### Step-by-Step Solution:

1. **Identify the Oxidation States**:
- In the reactants, \( M^{2+} \) has an oxidation state of +2, and \( M(s) \) (the solid metal) has an oxidation state of 0.
- In the products, \( 2M^{+} \) means that each \( M \) has an oxidation state of +1.

2. **Determine Changes in Oxidation States**:
- The solid metal \( M(s) \) is oxidized to \( M^{+} \) (oxidation state changes from 0 to +1).
- The ion \( M^{2+} \) is reduced to \( M^{+} \) (oxidation state changes from +2 to +1).

3. **Classify the Reaction**:
- Since there is both oxidation (from 0 to +1) and reduction (from +2 to +1) occurring in the reaction, it is a redox reaction.
- However, we need to determine if it is a disproportionation or comproportionation reaction.
- In a **disproportionation reaction**, a single species is both oxidized and reduced, while in a **comproportionation reaction**, two different oxidation states of the same element react to form a single product.

4. **Analyze the Reaction Type**:
- In this case, \( M^{2+} \) is being reduced to \( M^{+} \), and \( M(s) \) is being oxidized to \( M^{+} \).
- Since both \( M^{2+} \) and \( M(s) \) are different oxidation states of the same element \( M \) reacting to form \( M^{+} \), this reaction is classified as a **comproportionation reaction**.

### Final Answer:
The reaction \( M^{2+} (aq) + M(s) \rightleftharpoons 2M^{+} (aq) \) is an example of a **comproportionation reaction**.

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