Acids ______ H+ ions.

• A. Acids accept H+ ions
• B. Acids donate H+ ions
• C. Acids produce OH-
• D. Acids gain electrons

Answer: (B)

Acids donate H+ ions in solution. In Bronsted–Lowry terms, an acid is a substance that transfers a proton to a base. When an acid dissolves, it releases protons, which in water become H3O+. The base accepts the proton and becomes its conjugate acid, while the acid becomes its conjugate base. For example, hydrochloric acid donates a proton to water, producing Cl− and H3O+. The other statements don’t describe acid behavior: gaining H+ would describe bases, producing OH− is a property of bases in the Arrhenius view, and gaining electrons relates to redox, not acid–base chemistry.