(Solid + Liquid) phase diagram for the ternary potassium oxalate + hydrogen peroxide + water system at 283.15 K and 293.15 K

The solubility and density of the equilibrium liquid phase for the ternary K 2 C 2 O 4 + H 2 O 2 + H 2 O system were determined experimentally at (283.15 and 293.15) K. The phase diagrams of the system were constructed based on the measured solubility. The compound K 2 C 2 O 4 ·H 2 O 2 was confirmed by Schreinemaker's wet residues method. At (283.15 and 293.15) K, two solid phases were formed in the ternary K 2 C 2 O 4 + H 2 O 2 + H 2 O system that correspond to K 2 C 2 O 4 ·H 2 O and K 2 C 2 O 4 ·H 2 O 2 . Results indicated that the phase diagrams of the ternary system are similar at different temperatures. The double salt K 2 C 2 O 4 ·H 2 O 2 has a bigger crystallization field than either K 2 C 2 O 4 ·H 2 O or the mixture. The solubilities of K 2 C 2 O 4 ·H 2 O and K 2 C 2 O 4 ·H 2 O 2 increase slightly with increasing temperature, while the crystalline region of the compound K 2 C 2 O 4 ·H 2 O 2 decreases as the temperature increases.