Which of the following best describes a solution in which the pH equals 7?

A solution with a pH of 7 is classified as neutral because it indicates a balance between the concentrations of hydrogen ions (H⁺) and hydroxide ions (OH⁻) in the solution. In pure water at 25 degrees Celsius, the concentration of H⁺ ions is equal to that of OH⁻ ions, resulting in a neutral pH of 7. This neutrality is fundamental in understanding acid-base chemistry, as it signifies that the solution is neither acidic nor basic.

In contrast, an acidic solution has a pH lower than 7, reflecting a higher concentration of H⁺ ions compared to OH⁻ ions. A basic solution has a pH higher than 7, indicating a greater concentration of OH⁻ ions. The term "concentrated solution" refers to the amount of solute in a given volume of solvent and does not provide information about the acidity or basicity. Thus, a pH of 7 specifically designates a neutral solution, making it the correct choice.