Synthesis and enthalpy of formation of SrB4O7·3H2O

Hydrated strontium borate, SrB4O7·3H2O, has been synthesized and characterized by XRD, FT-IR, DTA-TG and chemical analysis. The molar enthalpy of solution of SrB4O7·3H2O in 1 mol dm−3 HCl(aq) was measured to be (21.15 ± 0.29) kJ mol−1. With incorporation of the previously determined enthalpies of solution of Sr(OH)2·8H2O(s) in [HCl(aq) + H3BO3(aq)] and H3BO3 in HCl(aq), and the enthalpies of formation of H2O(l), Sr(OH)2·8H2O(s) and H3BO3(s), the enthalpy of formation of SrB4O7·3H2O was found to be −(4286.7 ± 3.3) kJ mol−1.