量热法测定氯化铽甘氨酸配合物及其配离子的示准生成焓

采用具有恒温环境的反应量热计,在2 mol· L-1 HCl溶液中,分别测定TbCl3·6H2O (s)+ 3Gly(s)]和配合物Tb(Gly)3Cl3·3 H2O(s)在298.15 K时的溶解焓.根据盖斯定律设计一个热化学循环,得到六水氯化铽和甘氨酸配位反应的反应焓Δr Hmθ(298.15 K)=-6.247...

Determination of the standard molar formation enthalpies of complex of terbium chloride with glycine and coordination ion by calorimetry

The dissolution enthalpies of theTb（Gly）3.6H2O（s）＋3 Gly （s）] and Tb（Gly）3Cl3· 3H2O（s） in 2 mol·L-1 HCl solution have been measured at 298. 2 K by isoperibol calorimeter. The standard molar reaction enthalpy of the coordination reaction of terbium chloride with glycine has been determined by a thermoehemical cycle, △rHmθ（298. 15 K）=-6. 24710. 060 kJ.mol^-1. According to the results, the standard molar enthalpy of formation of Tb（Gly） 3 Cl3 · 3 H2O（s） has been calculated to be △rHmθ（298. 15 K）=-3 631.9±2.9 kJ.mol^- 1, and the molar dissolution enthalpy of Tb（Gly）3Cl3 · 3H2O（s） in water has been measured by isopribel calorimeter, the standard molar enthalpy of formation of Tb（Gly）33＋ （aq） has been calculated at 298. 15 K to be △rHmθ-Tb（Gly）3^3＋ ,aq,298. 15 K]=-2 260. 6±2.9 kJ·mol^-1.