Under Arrhenius theory, a base in water yields which ions?

Under Arrhenius theory, a base in water yields which ions?

• A. OH- ions
• B. H3O+ ions
• C. H+ ions
• D. NH4+ ions

Answer: (A)

Under Arrhenius theory, bases are substances that increase the concentration of hydroxide ions in an aqueous solution. When a base dissolves, it releases OH- into the water, as in NaOH → Na+ + OH-. Even bases like ammonia, which don’t contain OH- themselves, raise OH- levels by reacting with water: NH3 + H2O ⇌ NH4+ + OH-. This increase in hydroxide ions is what makes the solution basic. Hydronium ions (H3O+) are produced by acids, not bases, in water, and free H+ isn’t present as a separate species in solution. So the ion yielded by a base in water is hydroxide, OH-.

Under Arrhenius theory, bases are substances that increase the concentration of hydroxide ions in an aqueous solution. When a base dissolves, it releases OH- into the water, as in NaOH → Na+ + OH-. Even bases like ammonia, which don’t contain OH- themselves, raise OH- levels by reacting with water: NH3 + H2O ⇌ NH4+ + OH-. This increase in hydroxide ions is what makes the solution basic. Hydronium ions (H3O+) are produced by acids, not bases, in water, and free H+ isn’t present as a separate species in solution. So the ion yielded by a base in water is hydroxide, OH-.