Phase Equilibrium in the Aqueous Ternary System NaH₂PO₄ + CO(NH₂)₂ + H₂O at 298.15 K

Abstract

In this study, the solubilities and densities of a ternary system (NaH2PO4 + CO(NH2)2 + H2O) at 298.15 K was investigated using isothermal solution saturation and moist residues. According to the experimental results, the phase diagram and the diagram of densities versus composition were plotted. It turned out that there were one cosaturated point (CO(NH2)2 + NaH2PO4·2H2O), two univariant curves, and two crystallization regions corresponding to NaH2PO4·2H2O and CO(NH2)2 in this ternary system. The system belonged to a simple eutectic type, in which no double salt was formed. This research filled the blank of phase diagram in this ternary system and demonstrated the absence of double salt in the system.

Stable (solid+liquid) phase equilibrium for the ternary systems (K2SO4+KH2PO4+H2O), (K2SO4+KCl+H2O) at T=313.15K

“…It has aroused considerable interest with the advantage of wide frequency conversion, high efficiency, high damage threshold against high power laser [1]. In addition, it also can be used as a commercially valuable intermediate for producing the widest variety of derivatives, such as other potassium salts, penicillin and sodium glutamate [2,3]. Potassium Sulfate is widely used in agriculture.…”

Phase Equilibrium in the Aqueous Ternary System KH2PO4–NaH2PO4–H2O at 288.15 and 318.15 K

“…More details of the experimental method and the procedure of the transfer, collection, and preparation of samples are described in our previous papers. ,, …”

(Solid + Liquid) Phase Equilibrium in the Aqueous Ternary System NaH2PO4 + CO(NH2)2 + H2O at (308.15, 328.15, and 348.15) K

“…6,7 Analytical Method. The P 2 O 5 concentration was analyzed by the quinoline phosphomolybdate gravimetric method, 14 and the average relative deviation of the determination was less than 0.3 %.…”