Classifying ethanol reactions by type

Steps:

• Reaction 1 converts ethanol (CH3CH2OH) to acetic acid (CH3COOH) using O2, a loss of hydrogen equivalent to oxidation.
• Reaction 2 combines acetic acid (CH3COOH) and ethanol to form ethyl acetate (CH3COOCH2CH3) and water, defining esterification.
• Reaction 3 breaks down ethanol to acetaldehyde (CH3CHO), CO2, and H2O, matching a fermentation decomposition process.
• Match to options: Only D assigns oxidation to 1, esterification to 2, and fermentation to 3.

Why D is correct:

• D accurately identifies reaction 1 as oxidation (alcohol oxidized to carboxylic acid via O2), 2 as esterification (acid-alcohol condensation to ester), and 3 as fermentation (ethanol breakdown yielding aldehyde, CO2, H2O).

Why the others are wrong:

• A: Labels 1 as combustion, but combustion fully oxidizes to CO2/H2O, not partial to CH3COOH.
• B: Labels 1 as combustion (incorrect, as above) and 3 as addition (no addition of groups occurs).
• C: Labels 3 as addition (incorrect; it's decomposition, not bond addition).

Final answer: D