Question

Chemical Compounds

A: CH₃CH₂CHO

B: CH₃COCH₃

 

D: 

• A. \(A>C>D>B\)
• B. \(A>C>B>D\)
• C. \(C>A>D>B\)
• D. \(C>A>B>D\)

Hint:

- Aldehydes are more reactive than ketones due to lesser steric hindrance.
- Aliphatic aldehydes are more reactive than aromatic aldehydes due to lack of resonance stabilization.
- Ketones have two alkyl groups, which decrease electrophilicity, making them less reactive.
- Acetophenone (D) is the least reactive due to benzene ring stabilization.

Answer 1

The Correct Option is B

Step 1: Understanding Nucleophilic Addition Reactivity
- Aldehydes are more reactive than ketones towards nucleophilic addition due to lesser steric hindrance and a stronger partial positive charge on the carbonyl carbon.
- Aromatic aldehydes (C: Benzaldehyde) are less reactive than aliphatic aldehydes (A: Propanal) because of resonance stabilization in benzaldehyde.
- Ketones (B and D) are less reactive due to the presence of two alkyl groups that reduce the partial positive charge on the carbonyl carbon. Step 2: Reactivity Order Analysis
- A (CH₃CH₂CHO - Propanal): Highest reactivity due to being an aliphatic aldehyde.
- C (Benzaldehyde): Less reactive than aliphatic aldehydes but more reactive than ketones.
- B (Acetone - CH₃COCH₃): A simple ketone, less reactive than aldehydes.
- D (Acetophenone - C₆H₅COCH₃): Least reactive due to resonance stabilization from the benzene ring. Step 3: Conclusion
- Since aldehydes (A, C) are more reactive than ketones (B, D), the order is: \(A>C>B>D\)