Which type of solution has equal concentrations of H⁺ and OH⁻ ions?

A neutral solution is characterized by having equal concentrations of hydrogen ions (H⁺) and hydroxide ions (OH⁻). This balance contributes to the solution's stability in terms of pH. Specifically, in pure water at 25°C, the concentration of H⁺ ions is 1 x 10⁻⁷ moles per liter, which is exactly equal to the concentration of OH⁻ ions, also at 1 x 10⁻⁷ moles per liter. The result is a pH of 7, which is defined as neutral.

In contrast, acidic solutions contain a higher concentration of H⁺ ions compared to OH⁻ ions, resulting in a pH lower than 7. Alkaline solutions have a higher concentration of OH⁻ ions relative to H⁺ ions, leading to a pH higher than 7. Concentrated solutions, on the other hand, refer to the amount of solute present in a given volume of solvent but do not specifically pertain to the balance of H⁺ and OH⁻ ions, making this choice less relevant to the question. Thus, the definition of a neutral solution being one with equal concentrations of H⁺ and OH