An acid solution of pH equal to three is gradually diluted with water. As a result of this dilution, the pH of the solution will

The pH of a solution is a measure of its hydrogen ion concentration [H⁺], defined by the formula: pH = -log₁₀[H⁺]. An acidic solution has a pH less than 7, while a pH of 7 represents a neutral solution (like pure water).

When an acid solution (pH = 3) is diluted with water, the concentration of hydrogen ions in the solution decreases. According to the logarithmic scale, as the concentration of H⁺ ions decreases, the pH value increases. However, adding pure water (neutral pH) to an acid can never make the solution basic (pH > 7). Instead, as the solution becomes increasingly dilute, its pH will asymptotically approach 7, the pH of the diluent (water). Thus, the solution moves toward neutrality.