Phase equilibria and salting out of butyric acid in the ternary system potassium nitrate + water + 2-(2-butoxyethoxy)ethanol

Visual polythermal method in the bynary system of water-2-(2-butoxyethoxy) ethanol in the range of –25÷0° C the ice melting line is determined and the phase equilibria in the ternary system potassium nitrate–water–2-(2-butoxyethoxy) ethanol are studied in the range of 10.0–90.0° C. The ice melting line in the water–2-(2-butoxyethoxy) ethanol binary system is a flat, smooth line. This form of the melting line shows a hidden separation in liquid mixtures. It has been found that potassium nitrate salts out 2-(2-butoxyethoxy)ethanol from water-organic mixtures, and at 31.7° C in the ternary system of potassium nitrate–water–2-(2-butoxyethoxy)ethanol, separation begins. The compositions of the solutions corresponding to the critical solubility points at several temperatures have been determined. The isothermal phase diagrams of the ternary system at 10.0, 25.0, 30.0, 31.7, 35.0, 50.0, 90.0° С have been plotted. The distribution coefficients of 2-(2-butoxyethoxy) ethanol between the liquid phases of monotectic state have been calculated. It is shown that the effect of salting-out 2-(2-butoxyethoxy) ethanol from aqueous solutions with potassium nitrate increases with increasing temperature. The concentration of 2-(2-butoxyethoxy) ethanol in the organic phase of monotectics at 90.0° C is 90 wt.% with a distribution coefficient of 897.

Phase diagram of the β-alanine – water binary system

The phase diagram of the β-alanine–water binary system was studied using the visual polythermal method and the method of time–temperature curves in а temperature range of -20–90°С. There is a eutectic equilibrium at -18.3°С in the system; the solid phases of this equilibrium are ice and individual β-alanine. For the first time, the composition of the liquid phase of the eutectic state was determined.

EXTRACTION-SPECTROPHOTOMETRIC DETERMINATION OF NICKEL WITH 4-(2-PYRIDYLAZO) RESORCINOL IN THE NEONOL AF 9-10 – WATER SYSTEM

Phase equilibria in the neonol AF 9-10 – water system were studied using the visual-polythermal method. Value of lower critical dissolution temperature was determined (68°C). In order to assess the extraction capacity of system, the distribution of number of organic reagents was studied. It was found that increase in reagent hydrophilicity leads to decrease in its distribution coefficient. An extraction-spectrophotometric method for the determination of 1,2–2,4 mg/l nickel with 4-(2-pyridylazo) resorcinol (PAR) in the neonol AF 9-10 – water system has been proposed. It was found that ratio of nickel : PAR in the complex compound is 1: 2.