Integral enthalpies of mixing for water + lithium bromide + lithium iodide and water + lithium chloride + lithium nitrate at 298.15 K

Abstract

The analyses of absorption refrigerating machines, absorption heat pumps, and absorption heat transformers require thermal and physical properties for working medium + absorbent systems. The enthalpy of mixing data for working fluids are one of the most important basic properties for the research and the design of absorption refrigeration and heat pump systems. Differential enthalpies of dilution and differential enthalpies of solution for water + lithium bromide + lithium iodide (salt mole ratio 4:1) and water + lithium chloride + lithium nitrate (salt mole ratio 2.8:1) were measured with a twin isoperibol calorimeter at 298.15 K. Integral enthalpies of mixing for these two ternary systems at 298.15 K were measured as a function of mass fraction, and were exothermic in both ternary systems. The results were correlated by means of Redlich-Kister-type polynomials. The average absolute deviation between the experimental and the calculated values from these equations was 0.57 % for water + lithium bromide + lithium iodide and 0.52% for water + lithium chloride + lithium nitrate.