Thermal Dehydration of the Double Salts K₂Be(XO₄)₂×2H₂O (X: S, Se).

Abstract

Thermodynamic functions E 3000 Thermal Dehydration of the Double Salts K2Be(XO4)2·2H2O (X: S, Se). -Thermal dehydration of the title compounds is characterized by TG, DTA, DSC, powder XRD, IR, and Raman spectroscopy. The enthalpies of dehydration are calculated to be 87.6 kJ/mol and 167.5 kJ/mol for the sulfate and selenate compound, respectively. The enthalpies of formation are -4467.4 kJ/mol for K2Be(SeO4)2·2H2O and -3447.1 kJ/mol for K2Be(SO4)2·2H2O. The anhydrous double salt K2Be(SO4)2 forms tetragonal crystals, while K 2 Be(SeO 4 ) 2 , forms monoclinic crystals. -(GEORGIEV*, M. P.; STOILOVA, D. G.; MARINOVA, D. M.; KARADJOVA, V. A.; Cryst.