Density and refractive index for boric acid plus potassium chloride plus water and disodium tetraborate plus potassium chloride plus water systems at (20, 25, and 30) °C

Densities and refractive indices for two ternary systems, H3BO3 (1) + KCl (2) + H2O (3) and Na2B4O7 (1) + KCl (2) + H2O (3), have been measured at (20, 25, and 30) degreesC. Experimental study of the first ternary system was carried out for four values of total molality of the mixture approximate to (0.25, 0.50, 0.76, and 1.0) mol(.)kg(-1). Values for the dry base mole fraction of boric acid, y(1) = m(1)/(m(1) + m(2)) for each of the total molalities were approximately 0.25, 0.50, and 0.75. The total molalities of the second ternary system were approximately (0.10, 0.12, 0.14, and 0.17) mol(.)kg(-1). Variations of the dry base mole fraction of disodium tetraborate, Yi, were similar to those of the preceding ternary system. Data are also presented for the density and refractive index of binary systems including boric acid + water and disodium tetraborate + water at the three temperatures cited above. The range of concentrations in the measurements was 0.05-1.0 mol(.)kg(-1) for the H3BO3 (1) + H2O (2) system and 0.025-0.17 mol(.)kg(-1) for the Na2B4O7 (1) + H2O (2) system. For each ternary system, including the binary systems, the experimental results were fitted to an empirical equation with four non-temperature-dependent parameters.