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Assertion : Etard reaction helps to stop...

Assertion : Etard reaction helps to stop the oxidation of toluene at the aldehyde stage.
Reason : Chromyl chloride oxidises methyl group to a chromium complex, which on hydrolysis gives corresponding benzaldehyde.

A

If both assertion and reason are true and reason is the correct explanation of assertion.

B

If both assertion and reason are true but reason is not the correct explanation of assertion.

C

If assertion is true but reason is false.

D

If both assertion and reason are false.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze the assertion and reason provided regarding the Etard reaction. ### Step-by-Step Solution: 1. **Understanding the Assertion**: - The assertion states that the Etard reaction helps to stop the oxidation of toluene at the aldehyde stage. This means that during the reaction, toluene is converted to benzaldehyde, and the reaction does not proceed further to form carboxylic acid. 2. **Understanding the Reason**: - The reason provided states that chromyl chloride (CrO2Cl2) oxidizes the methyl group of toluene to form a chromium complex, which upon hydrolysis yields benzaldehyde. 3. **The Etard Reaction**: - The Etard reaction involves the reaction of toluene with chromyl chloride. The reaction can be summarized as follows: - Toluene (C6H5CH3) reacts with CrO2Cl2 to form a chromium complex. - This complex is then hydrolyzed (usually with H3O+) to produce benzaldehyde (C6H5CHO). 4. **Mechanism of the Reaction**: - Initially, toluene reacts with chromyl chloride, where the methyl group is oxidized to form a chromium complex. - The reaction can be represented as: \[ \text{C}_6\text{H}_5\text{CH}_3 + \text{CrO}_2\text{Cl}_2 \rightarrow \text{C}_6\text{H}_5\text{C}(\text{Cr})\text{Cl}_2 + \text{H}_2\text{O} \] - Upon hydrolysis, the chromium complex breaks down to yield benzaldehyde: \[ \text{C}_6\text{H}_5\text{C}(\text{Cr})\text{Cl}_2 + \text{H}_2\text{O} \rightarrow \text{C}_6\text{H}_5\text{CHO} + \text{Cr(OH)}_2 + \text{HCl} \] 5. **Conclusion**: - The assertion is correct because the Etard reaction indeed stops the oxidation of toluene at the aldehyde stage, producing benzaldehyde. - The reason is also correct as chromyl chloride oxidizes the methyl group to form a chromium complex, which on hydrolysis gives benzaldehyde. - Therefore, both the assertion and reason are true, and the reason correctly explains the assertion. ### Final Answer: Both the assertion and reason are correct, and the reason is a correct explanation of the assertion. ---
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