NEET
- Exam
- NEET
- Subject
- Chemistry
- Chapter
- Aldehydes and Ketones
NEET · Chemistry · Aldehydes and Ketones
Given below are two statements; one is labelled as Assertion (A)...
Given below are two statements; one is labelled as Assertion (A) and the other is labelled as Reason(R).
Assertion: Ketones react with ethylene glycol to form cyclic products known as ethylene glycol ketals in presence of dry HCl.
Reason: Dry hydrogen chloride protonates the oxygen of the carbonyl compounds and therefore, increases the electrophilicity of the carbonyl carbon facilitating the nucleophilic attack of glycol.
In the light of the above statements, choose the most appropriate answer from the options given below :
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A).
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A).
- C(A) is correct but (R) is not correct.
- D(A) is not correct but (R) is correct.
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A).
Step-by-step solution
Assertion (A):
"Ketones react with ethylene glycol to form cyclic products known as ethylene glycol ketals in the presence of dry HCl ."
- This statement is correct. Ketones do react with ethylene glycol under acidic conditions (such as dry HCl) to form cyclic ketals. The dry HCl acts as a catalyst in this reaction, facilitating the formation of the ketal.
Reason (R):
"Dry hydrogen chloride protonates the oxygen of the carbonyl compounds and therefore increases the electrophilicity of the carbonyl carbon, facilitating the nucleophilic attack of glycol."
- This statement is also correct. The reasoning provided here accurately explains how dry HCl increases the electrophilicity of the carbonyl carbon by protonating the carbonyl oxygen. This makes the carbonyl carbon more susceptible to nucleophilic attack by ethylene glycol, leading to ketal formation.
Conclusion:
- Both the Assertion (A) and the Reason (R) are correct.
- The Reason (R) correctly explains why the ketone reacts with ethylene glycol to form the cyclic ketal.
Thus, the correct answer is Option (1): "Both (A) and (R) are correct and (R) is the correct explanation of (A)."