Thermodynamics of the interaction of HCl with tert-butyl alcohol in water at 278.15–318.15 K

Abstract

Electromotive forces of cells without junctions: Pt, H₂(g, p°)∣HCl(m_E)∣ AgCl/Ag and Pt, H₂(g, p)∣HCl(m_E), TBA(m_N)∣AgCl/Ag (TBA =tert-butyl alcohol) have been measured at 10 K intervals from 278.15 to 318.15 K, where molality m_E= 0. 005–0.1 mol kg^–1 and m_N= 0.3–1.0 mol kg^–1. The salting-out constant k_S of TBA by HCI and the thermodynamic parameters of interaction, ƒ_EN(g_EN, h_EN, s_EN, c_p, _EN), of TBA with HCI in water have been evaluated. It has been shown that k_s > 0, g_EN > 0, h_EN > 0, S_EN > 0 (ca. 0 at 318.15 K) and c_p, _EN < 0 at all five temperatures. The signs of these parameters and their temperature dependence are discussed in terms of structural interaction and electrostatic models. The pair-interaction parameters of HCl–TBA and alkalimetal chloride–TBA in water have been compared. The dependence of the pair-interaction parameters on the number of carbon atoms in the hydrocarbon chain of monohydric alcohols has been interpreted on the basis of the group additivity and structural interaction models.