Question

What effect does the concentration of H⁺ (aq) ions have on the nature of a solution?

Answer 1

Acids furnish hydrogen ions (H⁺ ions) when dissolved in water. The more will be the concentration of H⁺ions in  a solution, the lower will be its pH. Thus, an increase in the concentration of H⁺ ions in a solution leads to increase in the acidity of the solution.