Acidic solutions are those that contain an excess of which species?

Acidic solutions are those that contain an excess of which species?

• A. H2 molecules
• B. H2O molecules
• C. H+ ions
• D. OH- ions

Answer: (C)

Acidic solutions are defined by having more hydrogen ions than other species in the solution. In water, those hydrogen ions are present as hydronium (H3O+) ions. Acids donate protons to the solution, increasing the concentration of H+ (or H3O+). The higher the H+ concentration, the more acidic the solution and the lower its pH. The other possibilities don’t explain acidity: H2 is just diatomic hydrogen and doesn’t define acidity in solution; H2O is the solvent, not a measure of acidity; OH− ions are characteristic of basic solutions, not acidic ones.

Acidic solutions are defined by having more hydrogen ions than other species in the solution. In water, those hydrogen ions are present as hydronium (H3O+) ions. Acids donate protons to the solution, increasing the concentration of H+ (or H3O+). The higher the H+ concentration, the more acidic the solution and the lower its pH.

The other possibilities don’t explain acidity: H2 is just diatomic hydrogen and doesn’t define acidity in solution; H2O is the solvent, not a measure of acidity; OH− ions are characteristic of basic solutions, not acidic ones.