Why a benzaldehyde less reactive than acetaldehyde towards nucleophilic addition reactions?

Explanation

To understand why benzaldehyde is less reactive than acetaldehyde towards nucleophilic addition reactions, we can analyze the structures and electronic effects of both compounds step by step.

### Step 1: Write the Structures
- **Benzaldehyde**: The structure of benzaldehyde is represented as a benzene ring with a formyl group (CHO) attached.
\[ \text{Benzaldehyde: } \text{C}_6\text{H}_5\text{CHO} \]
- **Acetaldehyde**: The structure of acetaldehyde is a simple aldehyde with a methyl group (CH3) attached to the carbonyl group (CHO).
...