Cannizzaro reaction is an example of

Options

A. Disproportionation reaction
B. Decomposition reaction
C. Condensation reaction
D. Displacement reaction

Answer

**Step-by-Step Solution:**

1. **Understanding Cannizzaro Reaction**: The Cannizzaro reaction is a chemical reaction that involves the disproportionation of aldehydes that do not have alpha-hydrogen atoms. This means that aldehydes lacking hydrogen atoms on the carbon adjacent to the carbonyl group undergo this reaction.

2. **Reaction Conditions**: The Cannizzaro reaction requires a strong base, typically concentrated sodium hydroxide (NaOH). This base facilitates the reaction by providing hydroxide ions (OH-) that are essential for the reaction to proceed.

3. **Mechanism of the Reaction**:
- In the presence of a strong base, one molecule of the aldehyde is oxidized to a carboxylate ion (RCOO-) while another molecule is reduced to an alcohol (RCH2OH).
- This process can be represented as:
\[ 2 RCHO + OH^- \rightarrow RCH2OH + RCOO^- \]
- Here, one aldehyde molecule is oxidized (loses electrons) and another is reduced (gains electrons), which is characteristic of a redox reaction.

4. **Types of Cannizzaro Reaction**:
- **Self-Cannizzaro Reaction**: This occurs when the same aldehyde is used in the reaction, resulting in the disproportionation of that aldehyde into an alcohol and a carboxylate ion.
- **Cross-Cannizzaro Reaction**: This occurs when two different aldehydes are used, leading to one being oxidized and the other being reduced.

5. **Conclusion**: The Cannizzaro reaction is classified as a redox reaction because it involves both oxidation and reduction processes occurring simultaneously. Specifically, it is a disproportionation reaction because one species is oxidized while another is reduced.

**Final Answer**: The Cannizzaro reaction is an example of a disproportionation redox reaction.

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