BioMedical Admissions Test (BMAT) 2026 – 400 Free Practice Questions to Pass the Exam

When ethanoic acid (acetic acid) reacts with sodium carbonate, the reaction leads to the formation of carbon dioxide gas. Ethanoic acid is a weak acid that reacts with sodium carbonate, a carbonate compound, resulting in an acid-base reaction. During this process, the carbonate ion (CO₃²⁻) from sodium carbonate reacts with the hydrogen ions (H⁺) from the ethanoic acid.

The key part of this reaction is the decomposition of the carbonate ion. Upon reacting with the acid, sodium carbonate produces carbonic acid (H₂CO₃), which is unstable and decomposes rapidly into carbon dioxide (CO₂) and water (H₂O). The evolution of gas is often observed as bubbling or fizzing during the reaction. Therefore, the primary gaseous product of this interaction is carbon dioxide, making this answer the correct one.

To clarify the context of the other options: Hydrogen gas is not a product of this specific acid-carbonate reaction; oxygen gas doesn’t form in the context of this reaction either, and nitrogen gas is unrelated to the reactants involved. The focus on carbon dioxide is essential for understanding the gas production in acid-carbonate reactions.