Which statement correctly describes Bronsted-Lowry acid-base theory?

• A. Proton donor/acceptor
• B. H+ and OH- yield
• C. Salt formation
• D. Electron transfer

Answer: (A)

Bronsted-Lowry theory centers on transfer of protons between reacting species. An acid is a substance that donates a proton (H+), while a base is one that accepts that proton. When this transfer occurs, the acid and base form their conjugate partners: the acid becomes its conjugate base, and the base becomes its conjugate acid. For example, HCl donates a proton to water, producing Cl− and H3O+. In another familiar case, NH3 accepts a proton from H2O to form NH4+, while the water molecule becomes OH−. This framework works in many solvents, not just water, which is a strength over definitions tied to H+ and OH− in aqueous solution.

Salt formation and neutralization are consequences of proton transfer, but they’re not the defining idea. Electron transfer relates to redox or Lewis acid-base concepts, which focus on electrons rather than protons, so it doesn’t capture the Bronsted-Lowry idea.