Concept:Alcohols react with aldehydes via a nucleophilic addition reaction to form unstable intermediates, which can further react to form stable ethers known as acetals.
Formula:$$ HCHO + 2C_2H_5OH \xrightarrow{dry \ HCl} H_2C(OC_2H_5)_2 + H_2O $$
Solution:- When one equivalent of ethyl alcohol reacts with formaldehyde, a hemiacetal is formed (containing one \( -OH \) and one \( -OR \) group).
- Hemiacetals are generally unstable. In the presence of excess alcohol and an acid catalyst, a second molecule of alcohol substitutes the hydroxyl group, releasing water.
- The final saturated product, characterized by a single carbon bonded to two alkoxy (\( -OR \)) groups, is called an Acetal.
Why other options are incorrect:The product cannot be an aldehyde, carboxylic acid, or acetone (a ketone) because those involve different oxidation states or carbon skeletons. Acetals are specialized di-ethers.
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