A new theoretical model for predicting the solubility of solid solutes in different solvents

• The new solubility model is based on intermolecular potential energy calculations.
• It provides detailed information to understand the solubility behavior of solutes.
• This new model is reliable for the prediction of solute solubility.

We present a new theoretical solubility model, which uses the statistical mechanical expression of activity coefficient and an estimation equation of molar intermolecular potential energy for species in fluid mixtures. The model equation of molar intermolecular potential energy consists of non-polar (van der Walls), electrostatic and hydrogen bonding interaction terms. The average accuracy of the model in correlating the molar intermolecular potential energy of pure species (30 solvents, 10 temperature points for each solvent) is 6.6%. We have examined this model for the solubility of 15 solutes in 36 different solvents (85 systems, 302 data points) over a temperature range of 268.15–402.4 K and a wide solubility range of 10−7−10−1 (mole fraction scale); the overall average relative error in predicted solubility (302 data points) is 17.384%; which shows that this method is reliable for the prediction of solute solubility in various solvents.