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(mE)∣ AgCl/Ag and Pt, H2(g, p)∣HCl(mE), TBA(mN)∣AgCl/Ag (TBA =tert-butyl alcohol) have been measured at 10 K intervals from 278.15 to 318.15 K, where molality mE= 0. 005–0.1 mol kg–1 and mN= 0.3–1.0 mol kg–1. The salting-out constant kS of TBA by HCI and the thermodynamic parameters of interaction, ƒEN(gEN, hEN, sEN, cp, EN), of TBA with HCI in water have been evaluated. It has been shown that ks > 0, gEN > 0, hEN > 0, SEN > 0 (ca. 0 at 318.15 K) and cp, 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.