Which statement correctly describes Arrhenius acid-base theory?

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

Answer: (A)

Arrhenius acid-base theory centers on the presence of specific ions in water: acids increase hydrogen ion (H+) concentration, while bases increase hydroxide ion (OH-) concentration. This framework explains why acids and bases neutralize each other and form water—the H+ from the acid combines with the OH- from the base. The statement referencing H+ and OH- captures this idea directly, making it the best match for Arrhenius chemistry. The other ideas describe different theories: proton transfer describes Bronsted-Lowry acids and bases (acids donate protons, bases accept them), while electron-pair donation refers to Lewis concepts. Hence, focusing on H+ and OH- in aqueous solution is the hallmark of Arrhenius.