Heats of solution/substitution and of fusion of Cs (1− x) K xCl compositions 0< x

Abstract

Measurements of the change in heat (enthalpy) of solid–solid transition Δ H t and of fusion Δ H fus in crystalline CsCl effected by the presence of guest ion K + up to 56.5 mol% using differential scanning calorimetry are reported. The range of K + solubility is found to be higher and at variance with the subsolidus region described in earlier reports. Novel features of Δ H t and Δ H fus dependence on solute composition are in contrast to parallel binary systems, viz. CsNO 3–RbNO 3, CsNO 3–TlNO 3 and RbNO 3–TlNO 3. Some fundamental solution quantities are calculated from heat of transition, viz. slope Δ H t/ x or Δ H ̄ solute and χ-apparent partial molar heat of solution and partial molar heat of solution at infinite dilution, respectively.