Why does not formaldehyde take part in aldol condensation?

Explanation

### Step-by-Step Solution:

1. **Understanding Aldol Condensation**:
Aldol condensation is a reaction that involves the formation of a β-hydroxy aldehyde or ketone (aldol) from two molecules of aldehyde or ketone, followed by dehydration to form an α,β-unsaturated carbonyl compound. The reaction requires the presence of an alpha hydrogen in the starting aldehyde or ketone.

2. **Identifying the Role of Alpha Hydrogen**:
In the mechanism of aldol condensation, a base abstracts an alpha hydrogen from the aldehyde or ketone. This leads to the formation of an enolate ion, which is a key intermediate in the reaction.

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