Given below are two statements: Statement I: Acidity of α-hydrogens of aldehydes and ketones is responsible for Aldol reaction. Statement II: Reaction between benzaldehyde and ethanal will NOT give Cross-Aldol product. Choose the most appropriate answer from the options given below : 

We need to evaluate the truth of two statements about the Aldol reaction.

Statement I: "Acidity of alpha-hydrogens of aldehydes and ketones is responsible for the Aldol reaction."

The Aldol reaction proceeds through the following mechanism:

1. A base abstracts an $$\alpha$$-hydrogen from one carbonyl compound, forming a resonance-stabilised enolate ion.

2. This enolate ion (a nucleophile) attacks the electrophilic carbonyl carbon of another molecule.

3. The resulting alkoxide is protonated to give the $$\beta$$-hydroxy aldehyde (aldol product).

The entire reaction depends on the ability to form the enolate, which in turn requires that the $$\alpha$$-hydrogen be sufficiently acidic ($$pK_a \approx 17{-}20$$ for typical aldehydes and ketones). Without acidic $$\alpha$$-hydrogens, the enolate cannot form and the Aldol reaction cannot proceed. Therefore, Statement I is correct.

Statement II: "Reaction between benzaldehyde and ethanal will NOT give a Cross-Aldol product."

Let us analyse the two reactants:

- Benzaldehyde ($$C_6H_5CHO$$): This aldehyde has no $$\alpha$$-hydrogen (the carbon adjacent to $$C=O$$ is part of the benzene ring). Therefore, benzaldehyde cannot form an enolate and cannot act as the donor component.

- Ethanal ($$CH_3CHO$$): This aldehyde has three $$\alpha$$-hydrogens on the methyl group. It can readily form an enolate ion.

In a cross-Aldol reaction between these two, ethanal provides the enolate (nucleophile), which attacks the carbonyl carbon of benzaldehyde (electrophile). This produces 3-hydroxy-3-phenylpropanal, which upon dehydration gives cinnamaldehyde ($$C_6H_5CH=CHCHO$$). This is a well-known reaction called the Claisen-Schmidt reaction.

Since the cross-Aldol product is formed, Statement II is incorrect.

The correct answer is Option 1: Statement I is correct but Statement II is incorrect.