Liquid-liquid equilibria, solubility and critical states in the system propionic acid – n-butanol – n-butyl propionate – water at 293.15 K and atmospheric pressure

Liquid–Liquid Equilibrium, Solubility, and Critical States in an Acetic Acid–n-Butyl Alcohol–n-Butyl Acetate–Water System at 328.15 K and 101.3 kPa: Topology of Phase Diagrams and NRTL Modeling

“…In contrast to the ″ordinary″ solubility, the compositions of the critical points were found by the specific luminescence of the solution in the critical region, namely, by blue opalescence. , Thus, the solution begins to opalesce during the titration, which means that the composition of the solution meets the critical one. We observed such an effect earlier, including for other systems of the acid–alcohol–ester–water type. ,,,, After fixing the critical composition, the results of the study were verified using the Coolledge method based on experimental LLE data. The average uncertainty of the cloud-point method was ± 0.005 mole fraction.…”

“…The shape of the heterogeneous region (binodal surface) resembles a segment of a torus. Some of the studies carried out with the systems consisting acid, alcohol, ester, and water have a similar shape: n -butanol–propionic acid– n -butyl propionate–water; , n -amyl alcohol–acetic acid– n -amyl acetate–water …”

“…Each of the secants had a certain ratio of the concentrations of the two components (alcohol and ester): 1:3, 1:1, and 3:1 (Figure ). This approach was applied in our previous studies. ,− …”

“…The titration until the solution becomes cloudy was carried out in a special thermostatically controlled vial (with the use of a thermostat LOIP LT-105 (± 0.05 K)) at 328.15 K and 101.3 kPa. A description of this approach is set out in our previously published studies. ,, Samples (binary and ternary) were prepared by the gravimetric method using an analytical balance Ohaus Pioneer PA214. Based on the amount of titrant used for titration of the solution, the composition of the mixture was determined.…”

“…A description of this approach is set out in our previously published studies. 6,15,16 Samples (binary and ternary) were prepared by the gravimetric method using an analytical balance Ohaus Pioneer PA214. Based on the amount of titrant used for titration of the solution, the composition of the mixture was determined.…”