Which liquid is typically considered neutral with a pH of 7?

Pure water is typically considered neutral with a pH of 7 because it has equal concentrations of hydrogen ions (H⁺) and hydroxide ions (OH⁻), resulting in a balanced state. This neutrality is essential in various chemical and biological processes, making pure water a universal solvent.

In contrast, vinegar is acidic with a pH less than 7 due to acetic acid, while saltwater, depending on its composition, can also be slightly acidic or basic but is generally closer to 7 than vinegar. Soap solution usually has a pH greater than 7, making it alkaline due to the presence of fatty acids and bases during its production. Therefore, pure water is the only liquid in the options given that consistently maintains a neutral pH of 7.