How are the properties of acids and bases determined in Arrhenius theory?

In Arrhenius theory, the properties of acids and bases are primarily determined by the presence of specific ions in solution. According to this theory, an acid is defined as a substance that increases the concentration of hydrogen ions (H⁺) in aqueous solution, while a base is defined as a substance that increases the concentration of hydroxide ions (OH⁻) in solution.

This direct correlation between the dissociation of acids and bases in water and the resultant ions they release is fundamental to understanding their behavior in chemical reactions. The presence of H⁺ makes solutions acidic, while the presence of OH⁻ makes solutions basic. This is the cornerstone of the Arrhenius definition, which focuses on these ions being responsible for the characteristic properties of acidity and basicity.

While boiling and freezing points, conductivity, viscosity, and density can provide additional insights into the solutions, they do not align with the fundamental principles set out in Arrhenius theory for defining acids and bases. The behavior of substances in terms of H⁺ and OH⁻ ions is what fundamentally characterizes them within this theoretical framework.