New synthetic method and thermochemistry of szaibelyite

A new synthetic method of szaibelyite (2MgO·B2O3·H2O) has been reported. The enthalpy of solution of 2MgO·B2O3·H2O in 2.9842 mol dm−3 HCl (aq) was determined. From a combination of this result with measured enthalpies of solution of H3BO3 in 2.9842 mol dm−3 HCl (aq) and of MgO in (HCl+H3BO3) solution, together with the standard molar enthalpies of formation of MgO (s), H3BO3 (s), and H2O (l), the standard molar enthalpy of formation of −(2884.36±1.82) kJ mol−1 of 2MgO·B2O3·H2O was obtained.