Which statement best describes the solution produced when an Arrhenius acid is dissolved in water?

Which statement best describes the solution produced when an Arrhenius acid is dissolved in water?

• A. The only positive ion in solution is H+.
• B. The only negative ion in solution is OH-.
• C. The only positive ion in solution is NH4+.
• D. The only negative ion in solution is HCO3-.

Answer: (A)

Dissolving an Arrhenius acid in water releases protons that appear in solution as hydronium ions (H3O+). In aqueous solution, the positive charge carried by the acid-derived species is the hydronium ion, so it’s common to describe the positive ion simply as H+ to reflect that proton transfer has occurred. The counterion left behind is the acid’s conjugate base, not hydroxide, so hydroxide ions (OH−) are not the defining negative species in these acidic solutions. Hydroxide would be present only from water’s own autoionization or if the solution were basic, not as a characteristic product of a typical Arrhenius acid. Other ions listed would require specific acids (for example, NH4+ would come from an ammonium-containing system, and HCO3− from carbonic acid scenarios). They aren’t the general outcome of dissolving a typical Arrhenius acid in water.

Dissolving an Arrhenius acid in water releases protons that appear in solution as hydronium ions (H3O+). In aqueous solution, the positive charge carried by the acid-derived species is the hydronium ion, so it’s common to describe the positive ion simply as H+ to reflect that proton transfer has occurred. The counterion left behind is the acid’s conjugate base, not hydroxide, so hydroxide ions (OH−) are not the defining negative species in these acidic solutions. Hydroxide would be present only from water’s own autoionization or if the solution were basic, not as a characteristic product of a typical Arrhenius acid.

Other ions listed would require specific acids (for example, NH4+ would come from an ammonium-containing system, and HCO3− from carbonic acid scenarios). They aren’t the general outcome of dissolving a typical Arrhenius acid in water.