H⁺ represents hydrogen ions in chemistry. In aqueous solutions, these are responsible for the acidity of the solution and determine its pH value.
Hydroxide ions are found in basic solutions and combine with H⁺ ions to form water molecules.
A solution that has an excess of H⁺ ions compared to OH⁻ ions.
A solution that has an excess of OH⁻ ions compared to H⁺ ions.