Solubility Simulator

Enter values for either Si (intrinsic solubility) or Saq (aqueous solubility), for Ka (compulsory), and for either Kw or the temperature in degrees Celsius. The applet will calculate the missing values. If you fill in both Si and Saq, it will ignore the Saq value; if you give both Kw and temperature, it will ignore the temperature.

The calculation of Si and Saq assumes that ionised species are infinitely soluble. The relationship between Kw and temperature is taken from the table in J. Phys. Chem. Ref. Data 1981, 10, 295. This gives values between 0 and 100 degrees Celsius in five degree increments. Linear interpolation is used between the points, which should be reasonable. Linear extrapolation is used below zero and above one hundred degrees Celsius. This is not closely related to reality.

The unit for Kw is molality (moles per kilogram of water). For dilute solutions, this is close to molarity (moles per litre of water).

For an example, see:

Diclofenac Solubility: Independent Determination of the Intrinsic Solubility of Three Crystal Forms

A. Llinàs, J. C. Burley, K. J. Box, R. C. Glen, and J. M. Goodman J. Med. Chem. 2007, 50, 979-983.

DOI: 10.1021/jm0612970