四元体系RbCl-CeCl_3-HCl-H_2O(25℃)的相平衡及其新相化合物  

Phase Equilibrium of RbCl-CeCl_3-HCl-H_2O System at 25 ℃ and New Solid Phase Compound

作　　者：乔占平[1] 卓立宏[1] 郭应臣[1] 王惠[2] 

机构地区：[1]南阳师范学院化学与制药工程学院,河南南阳473061 [2]西北大学化学系,陕西西安710069

出　　处：《中国稀土学报》2007年第6期651-655,共5页Journal of the Chinese Society of Rare Earths

基　　金：河南省自然科学基金资助项目(0511044900)

摘　　要：测定了四元体系RbCl-CeCl3-HCl-H2O在25℃时的溶度数据,绘制了相应的溶度图。该四元体系是由3个固相区RbCl（原始盐）,RbCl.CeCl3.4H2O,CeCl3.7H2O（原始盐）组成的复杂体系,其中RbCl.CeCl3.4H2O是固液同成分溶解度的化合物。在相平衡结果指导下,制备了化合物RbCl.CeCl3.4H2O,并对其进行了X射线粉末衍射鉴定和热重分析,结果表明,该化合物在84-216℃通过两步失去其结晶水。用RD496-Ⅲ-2000微量热计测定了298.15 K下新相化合物在水中的溶解焓（-23.70±0.11）kJ·mol^-1,计算出其标准摩尔生成焓为（-2735.6±1.1）kJ·mol^-1。The solubility of saturated solutions of quaternary system RbCl-CeCl3-HCl-H2O at 25 ℃ was determined and the corresponding equilibrium diagramwas constructed. The quaternary system was complicated with three stable equilibrium solid phases RbCl, RbCl· CeCl3· 4H2O and CeC13 ·7H2O. The compound RbCl· CeCl3·4H2O was congruently in the aqueous system and did not reported in literatures. The 1：1 type compound obtained was identified and characterized by the method of X-ray diffraction and the thermal analysis methods of thermogravimetry-differential thermogravimetry （TG-DTG）. Results showed that the compound lost its crystal water by two steps from 84 to 216 ℃. The standard molar enthalpy of solution of RbCl· CeCl3 · 4H2O （s） in deionized water was deter- mined to be （ - 23.7 ± 0.11） kJ· mol^- 1 with the heat conduction microcalorimeter, its standard molar enthalpy of formation was calculated as （ - 2735.6 ± 1.1） kJ·mol^-1.

关 键 词：四元体系 相平衡 氯化铷 氯化亚铈 标准摩尔生成焓 稀土 

分 类 号：O642.4[理学—物理化学]