The decarboxylation of ethanoic acid will produce carbon(IV) oxide and

Correct answer: Methane

Explanation: Decarboxylation removes the –COOH group as CO₂, and the remaining alkyl fragment becomes an alkane with one fewer carbon. Ethanoic acid (2 carbons) therefore yields the 1-carbon alkane, methane (CH₄).

Typical reaction (soda-lime decarboxylation, using the sodium salt):
CH₃COONa + NaOH → CH₄ + Na₂CO₃

• Methane — Correct.
• Ethane — Would come from propanoic (3-carbon) acid.
• Propane — Would come from butanoic (4-carbon) acid.
• Butane — Would come from pentanoic (5-carbon) acid.