七水氯化镧与三氯醋酸配合物的热化学研究

A Thermochemical Study on the Coordination Complexe of Lanthanum Chloride Seven-Hydrate with Trichloroacetate Acid

为了深入研究三氯醋酸镧配合物性质 ,用溶解量热法 ,在自行研制的具有恒定温度环境的新型反应量热计中 ,测定了 L a Cl3.7H2 O(s) ,CCl3COOH(s)和 L a(TCA) 3.3H2 O(s)在 1mol/ L HCl中的溶解焓 .再根据盖斯定律设计了一个热化学循环 ,计算得到了七水合氯化镧与三氯醋酸反应的反应焓 Δr Hm (2 98.15 K) =2 0 5 .0 0 9k J/ mol,并求出了 L a(TCA) 3.3H2 O(s)的标准生成焓 Δf Hm [L a(TCA) 3.3H2 O,(s) ,2 98.15 K]=- 30 6 8.35 k J/ m

In order to make a deep research on lanthanum trichloroacetic acid, the standard molar reaction enthalpies of the reaction , LaCl 3·7H 2O(s) +3CCl 3COOH(s)( TCA) = La(TCA) 3·3H 2O(s) +3HCl(g) +4H 2O(l) was studied by the classical solution calorimetry . The molar dissolution enthalpies of the reactants and the products of the reactions in certain solvent in 1 mol/L HCl was measured by using an isoperibol calorimeter . From the results and other auxiliary quantities , the standard molar formation enthalpies of [La(TCA) 3·3H 2O,(s),298.15 K] was determined to be Δ f H m [La (TCA) 3·3H 2O,(s),298.15 K]= -3 068.35 kJ/mol.