Density and Refractive Index for Boric Acid + Potassium Chloride + Water and Disodium Tetraborate + Potassium Chloride + Water Systems at (20, 25, and 30) °C

Densities and refractive indices for two ternary systems, H 3 BO 3 (1) + KCl (2) + H 2 O (3) and Na 2 B 4 O 7 (1) + KCl (2) + H 2 O (3), have been measured at (20, 25, and 30) °C. Experimental study of the first ternary system was carried out for four values of total molality of the mixture ≈(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, y 1, 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 H 3 BO 3 (1) + H 2 O (2) system and 0.025−0.17 mol·kg -1 for the Na 2 B 4 O 7 (1) + H 2 O (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.