A new magnesium borate 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O has been synthesized by the method of phase transformation of double salt under hydrothermal condition and characterized by XRD,IR,Raman spectra and TG. Th...A new magnesium borate 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O has been synthesized by the method of phase transformation of double salt under hydrothermal condition and characterized by XRD,IR,Raman spectra and TG. The enthalpy of solution of 2MgO· B_ 2 O_ 3 ·1.5H_ 2 O in 2.9842 mol·L -1 HCl was determined. From a combination of this result with measured enthalpies of solution of H_ 3 BO_ 3 in 2.9842 mol·L -1 HCl(aq.) and of MgO in (HCl+H_ 3 BO_ 3 ) solution,together with the standard molar enthalpies of formation of MgO(s),H_ 3 BO_ 3 (s),and H_ 2 O(l),the standard molar enthalpy of formation of -(3019.76±1.79) kJ· mol -1 of 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O was obtained.展开更多
基金ProjectsupportedbytheNaturalScienceFoundationofShaanxiProvinceofChina (No .2 0 0 2B13 )
文摘A new magnesium borate 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O has been synthesized by the method of phase transformation of double salt under hydrothermal condition and characterized by XRD,IR,Raman spectra and TG. The enthalpy of solution of 2MgO· B_ 2 O_ 3 ·1.5H_ 2 O in 2.9842 mol·L -1 HCl was determined. From a combination of this result with measured enthalpies of solution of H_ 3 BO_ 3 in 2.9842 mol·L -1 HCl(aq.) and of MgO in (HCl+H_ 3 BO_ 3 ) solution,together with the standard molar enthalpies of formation of MgO(s),H_ 3 BO_ 3 (s),and H_ 2 O(l),the standard molar enthalpy of formation of -(3019.76±1.79) kJ· mol -1 of 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O was obtained.
