Concept:The oxidation of a primary alcohol can yield either an aldehyde or a carboxylic acid, depending heavily on the reaction conditions.
Formula:$$ CH_3CH_2OH \xrightarrow{[O]} CH_3CHO \xrightarrow{[O]} CH_3COOH $$
Solution:- Ethyl alcohol (ethanol) is a primary alcohol.
- When oxidized with sodium dichromate (\( Na_2Cr_2O_7 \)) and sulfuric acid, it first converts to acetaldehyde.
- Because aldehydes are highly susceptible to further oxidation into carboxylic acids, the student deliberately distilled the product immediately.
- Acetaldehyde has a much lower boiling point than both ethanol and acetic acid, allowing it to escape the oxidizing mixture rapidly before further oxidation can occur.
Why other options are incorrect:If refluxed instead of distilled, the product would be acetic acid (Option C). Acetone is formed from 2-propanol, not ethanol. Dimethyl ether requires dehydration conditions (conc. \( H_2SO_4 \) at 140°C), not oxidation.
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