Question

What type(s) of ion(s) is/are present in every aqueous solution?

1) H+
2) OH⁻
3) H+ and OH⁻
4) Na+ and Cl-

Answer 1

Every aqueous solution contains both hydronium (H3O+) and hydroxide (OH−) ions, which determine the solution's acidity or basicity.

Step-by-step explanation:

The types of ions present in every aqueous solution are hydronium ions (H+) or more accurately H3O+ and hydroxide ions (OH−). Pure water naturally dissociates to a very small extent into these ions, and thus, they are present in all aqueous solutions.

The relationship between hydronium and hydroxide ion concentrations is governed by the ion product of water (Kw), which at 25°C equals 1.0 x 10−7.

A solution with equal concentrations of H3O+ and OH− is neutral, whereas a solution with a higher concentration of H3O+ is acidic and one with a higher concentration of OH− is basic.