A new magnesium borate MgO·B 2O 3·4H 2O was synthesized by the method of phase transformation of double salt and characterized by XRD, IR spectra and TG. The structural formula of this compound was Mg[B ...A new magnesium borate MgO·B 2O 3·4H 2O was synthesized by the method of phase transformation of double salt and characterized by XRD, IR spectra and TG. The structural formula of this compound was Mg[B 2O(OH) 6]·H 2O. The enthalpy of solution of MgO·B 2O 3·4H 2O in HCl (1.0492 mol·L -1) was determined. With the incorporation of the standard molar enthalpies of formation of MgO (s), H 3BO 3 (s), and H 2O (l), the standard molar enthalpy of formation of -(3135.31±1.68) kJ·mol -1 of MgO·B 2O 3·4H 2O was obtained. Thermodynamic properties of this compound were also calculated by group contribution method.展开更多
文摘A new magnesium borate MgO·B 2O 3·4H 2O was synthesized by the method of phase transformation of double salt and characterized by XRD, IR spectra and TG. The structural formula of this compound was Mg[B 2O(OH) 6]·H 2O. The enthalpy of solution of MgO·B 2O 3·4H 2O in HCl (1.0492 mol·L -1) was determined. With the incorporation of the standard molar enthalpies of formation of MgO (s), H 3BO 3 (s), and H 2O (l), the standard molar enthalpy of formation of -(3135.31±1.68) kJ·mol -1 of MgO·B 2O 3·4H 2O was obtained. Thermodynamic properties of this compound were also calculated by group contribution method.
