Arrange the following in decreasing order of their reactivity towards nucleophilic addition reaction

A. \(CH_3CHO\)

B. \(CH_3CH_2CHO\)

C. \(CH_3COCH_3\)

D. \(CH_3COCH_2CH_3\)

E. \(C_6H_5COCH_3\)

Choose the correct answer from the options given below:

A, B, C, D, E

The correct answer is option 1. A, B, C, D, E.

The reactivity of carbonyl compounds towards nucleophilic addition reactions is influenced by various factors such as the nature of the carbonyl group, steric hindrance, and electron-donating or withdrawing effects of substituents. Generally, aldehydes and ketones undergo nucleophilic addition reactions at the carbonyl carbon. Let's analyze each compound:

A. \(CH_3CHO\) (Acetaldehyde) - This is a simple aldehyde. Aldehydes are generally more reactive than ketones in nucleophilic addition reactions due to the greater electrophilicity of the carbonyl carbon compared to ketones.

B. \(CH_3CH_2CHO\) (Propanal) - Similar to A, this is also an aldehyde, but it has an ethyl group attached to the carbonyl carbon. The presence of the ethyl group might slightly decrease the reactivity compared to acetaldehyde, but it should still be quite reactive.

C. \(CH_3COCH_3\) (Acetone) - This is a simple ketone. Ketones are generally less reactive than aldehydes in nucleophilic addition reactions due to the presence of two alkyl groups which provide steric hindrance.

D. \(CH_3COCH_2CH_3\) (2-Butanone) - Similar to acetone, this is a ketone with two alkyl groups attached to the carbonyl carbon, providing more steric hindrance. Therefore, it should be less reactive than acetone.

E. \(C_6H_5COCH_3\) (Acetophenone) - This compound has a phenyl group attached to the carbonyl carbon. The phenyl group can stabilize the carbonyl carbon through resonance, making the compound less reactive compared to simple ketones like acetone and 2-butanone.

Based on this analysis, the decreasing order of reactivity towards nucleophilic addition reaction should be option 1. A, B, C, D, E.