Which statement correctly describes Arrhenius acids and bases?

Which statement correctly describes Arrhenius acids and bases?

• A. An acid increases H+ in solution.
• B. A base increases H+ in solution.
• C. Acids cause solutions to be alkaline.
• D. Bases donate protons.

Answer: (A)

Arrhenius acids are defined by increasing the concentration of hydrogen ions in aqueous solution. In water, those H+ ions almost immediately form hydronium (H3O+), which makes the solution acidic. The statement that an acid increases H+ in solution captures this idea directly. Bases, by contrast, increase the concentration of hydroxide ions (OH-), which makes solutions alkaline. The other options miss this simple pairing: acids don’t make solutions alkaline, bases don’t increase H+, and “donate protons” is a idea from a different concept (Brønsted–Lowry) rather than Arrhenius.

Arrhenius acids are defined by increasing the concentration of hydrogen ions in aqueous solution. In water, those H+ ions almost immediately form hydronium (H3O+), which makes the solution acidic. The statement that an acid increases H+ in solution captures this idea directly. Bases, by contrast, increase the concentration of hydroxide ions (OH-), which makes solutions alkaline. The other options miss this simple pairing: acids don’t make solutions alkaline, bases don’t increase H+, and “donate protons” is a idea from a different concept (Brønsted–Lowry) rather than Arrhenius.