Heats of solution/substitution and of fusion of Cs(1−x)KxCl compositions 0

Measurements of the change in heat (enthalpy) of solid–solid transition ΔHt and of fusion ΔHfus 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 ΔHt and ΔHfus dependence on solute composition are in contrast to parallel binary systems, viz. CsNO3–RbNO3, CsNO3–TlNO3 and RbNO3–TlNO3. Some fundamental solution quantities are calculated from heat of transition, viz. slope ΔHt/x or and χ-apparent partial molar heat of solution and partial molar heat of solution at infinite dilution, respectively.