Solid–liquid equilibrium of 1-hydroxyethane-1,1-diphosphonic acid in different solvents

The solubilities of 1-hydroxyethane-1,1-diphosphonic acid in five different solvents including ethanol, isopropyl alcohol, n-propyl alcohol, acetone and acetic acid were determined at temperatures ranging from 288.45 to 327.95 K at atmospheric pressure using a gravimetric method. Van’t Hoff equation was used to correlate the experimental solubility data. The calculated values of van’t Hoff equation were found to be in good agreement with the experimental data. Further, the dissolution enthalpy and entropy of HEDP in the corresponding solvents were predicted.