Question

What is the correct sequence of increasing reactivity of the following compounds towards nucleophilic addition reaction? (A) Ethanal
(B) Propanone
(C) Propanal
(D) Butanone

• A. (A), (B), (C), (D)
• B. (D), (B), (C), (A)
• C. (A), (C), (B), (D)
• D. (C), (B), (D), (A)

Hint:

Aldehydes are generally more reactive towards nucleophilic addition than ketones because they experience less steric hindrance and the carbonyl carbon is more electrophilic.

Answer 1

The Correct Option is A

Step 1: Nucleophilic Addition Reaction.
Nucleophilic addition reactions involve nucleophilic attack on the carbonyl group (C=O) of aldehydes and ketones. The reactivity depends on the steric and electronic factors around the carbonyl group.
Step 2: Analyze the Compounds.
- (A) Ethanal: Ethanal is an aldehyde, and aldehydes are typically more reactive than ketones due to less steric hindrance.
- (B) Propanone: Propanone is a ketone with two methyl groups attached to the carbonyl carbon, making it less reactive than aldehydes.
- (C) Propanal: Propanal is an aldehyde, similar to ethanal but with a propyl group attached, making it slightly less reactive than ethanal.
- (D) Butanone: Butanone is a ketone with larger alkyl groups, thus the least reactive in nucleophilic addition.
Step 3: Conclusion.
The correct sequence of increasing reactivity is:
(1) (A) Ethanal → (2) (B) Propanone → (3) (C) Propanal → (4) (D) Butanone.
Final Answer: \[ \boxed{\text{The correct sequence is (A), (B), (C), (D).}} \]