Study on Determination of Standard Molar Enthalpy of Formation for Complex of Europium Chloride with Glycine and Alanine by Calorimetry

The ternary complex of Eu(Gly) 2 (Ala) 3 Cl 3 •2H 2 O(Gly = Glycine and Ala = Alanine) was synthesized and characterized by comparison of elementary analysis, chemical analysis, thermogravimetric analysis, and data with corresponding.The dissolution enthalpies of the EuCl 3 •6H 2 O(s), 2Gly(s) + 3Ala(s) and Eu(Gly) 2 (Ala) 3 Cl 3 •2H 2 O(s) in 2 mol/L HCl solution have been measured at 298.15K by isoperibol calorimeter.Based on the results, by designing a thermochemical cycle in terms of Hess' Law and through calculation, The standard molar reaction enthalpy of Europium chloride six-hydrate with Glycine and Alanine has been determined:Δ H (298.15K) = -51.780kJ/mol, and the standard enthalpy of formation of Eu(Gly) 2 (Ala) 3 Cl 3 •2H 2 O(s) has been calculated to be θ m f Δ H [Eu(Gly) 2 (Ala) 3 Cl 3 •2H 2 O(s), 298.15K] = -4488.8kJ/mol.