【摘要】 本文用热分析方法探讨了在不同水蒸气分压下LaCl₃·7H₂O的脱水过程,首次得到了基本分离的LaCl₃·2H₂O,并确定了它的存在条件,同时还发现并制备了尚未见报道的LaCl₃·5H₂O。更多还原

【Abstract】 By means of TG, DTG, and DTA technique, the dehydration process of LaCl₃·7H₂O has been investigated. It is found that the mechanisms of dehydration process are different under different H₂O-vapor pressures: when P_H2O=1～6mmHg, the mechanism of dehydration is lanthanum chloride heptahydrate→trihydrate→dihydrate→monohydrate→anhydrous; when P_H2O=10～100mmHg, heptahydrate→trihydrate→monohydrate→anhydrous and when P_H2O=150mmHg, heptahydrate→pentahydrate→monohydrate→anhydrous. From the thermal analysis curve, the apparently separated LaCl₃·5H₂O has been found for the first time, and conditions for its existing have been defined. The LaCl₃·5H₂O, which has not been reported yet in the literature, is discovered, too, and has been identified by preparation.更多还原