Reagents for oxidizing primary alcohols

Steps:

• Recognize CH3CH2OH as ethanol, a primary alcohol that can be oxidized to ethanal or ethanoic acid.
• Strong oxidizing agents under reflux conditions achieve complete oxidation to carboxylic acids.
• Acidified potassium dichromate(VI) reacts with primary alcohols, changing from orange to green as Cr(VI) reduces to Cr(III).
• Evaluate options: A and B are strong oxidants, but B is standard for alcohol oxidation; C targets aldehydes only.

Why B is correct:

• Acidified K2Cr2O7 oxidizes primary alcohols to carboxylic acids via Cr2O7^2- + 14H+ + 6e- → 2Cr^3+ + 7H2O, producing CH3COOH from CH3CH2OH under reflux.

Why the others are wrong:

• A. Acidified KMnO4 oxidizes alcohols but is less selective for controlled conditions, often used for alkenes or full decolorization.
• C. Tollens' reagent (AgNO3/NH3) oxidizes aldehydes to carboxylic acids but does not react with alcohols.
• D. Not enough information.

Final answer: B