Thermochemical Properties of n-Undecylammonium Bromide Monohydrate C11H28BrNO(s)

Abstract

The crystal structure of n-undecylammonium bromide monohydrate was determined by X-ray crystallography. The crystal system of the compound is monoclinic, and the space group is P21/c. Molar enthalpies of dissolution of the compound at different concentrations m/(mol·kg−1) were measured with an isoperibol solution–reaction calorimeter at T = 298.15 K. According to the Pitzer’s electrolyte solution model, the molar enthalpy of dissolution of the compound at infinite dilution (\( \Updelta_{\text{sol}} H_{\text{m}}^{\infty } \)) and Pitzer parameters (\( \beta_{\text{MX}}^{(0)L} \) and \( \beta_{\text{MX}}^{(1)L} \)) were obtained. Values of the apparent relative molar enthalpies (\( {}^{\Upphi }L \)) of the title compound and relative partial molar enthalpies (\( \bar{L}_{2} \) and \( \bar{L}_{1} \)) of the solute and the solvent at different concentrations were derived from experimental values of the enthalpies of dissolution.