Temperature Effect on the Acid–Base Properties of β-Alanine in Aqueous Solution

The acid–base properties of β-alanine (β-Ala) in aqueous solution were studied by the pH-metric method in the temperature range 278.2–318.2 K and at I = 0.1 M KCl. The ionization constants (pK_i) of β‑Ala at different temperatures were calculated. The ionization constants were found to change depending on the temperature: an increase in the temperature leads to a decrease in pK_i for both carboxyl and amine groups, which indicates that the degree of ionization of β-alanine increased and its acidic properties were enhanced. The thermodynamic characteristics (ΔН⁰, ΔS⁰, and ΔG) of the corresponding ionization processes were determined by the temperature coefficient method.