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Navigation: User Guide ➔ Stream Properties ➔ Solubility

Standard Species Model Stream Properties Special Cases
Species Model
Stream Properties
Density Heat of Formation Heat of Dilution Specific Heat
Solubility Boiling Point Elevation pH Charge Steam and Water Sulfuric Acid

Related Links: Potash Solubility, Entering Solubility Data in the Species Properties Database, Enabling and Disabling Solubility in a Project


The Solubility of a liquid or solid in a Solvent is the mass of that species dissolved in a fixed mass of Solvent which is in equilibrium with an excess of the species at a given temperature. The solution is said to be Saturated at these conditions.

When the user enters solubility data for a species in the Species Database, then SysCAD will calculate the saturated solubility in solution for that species throughout a project.

  • If there is sufficient excess of the solid form then SysCAD will dissolve sufficient mass to achieve a saturated solution.
  • If there is an excess of the dissolved species, then SysCAD will automatically convert the excess to the other phase (usually the solid form).

SysCAD will automatically calculate the Heat of Reaction (HOR) for the dissolution or precipitation reaction based on the thermodynamic data in the Species database for the two species of interest.

As an example, if the species involved is FeCl3:

  • If there is an excess of FeCl3(s) then SysCAD will dissolve the solid form to obtain a saturated solution of FeCl3(aq), with an associated drop in temperature (this is an endothermic reaction);
  • If there is an excess of the aqueous species, then SysCAD will precipitate it to the solid form, FeCl3(s), with an associated rise in temperature (this is an exothermic reaction).

Solubility is one of the Phase Change options available in SysCAD.

Implementation in SysCAD

Potash Solubility

The solubility of the KCl-NaCl-MgCl2-CaSO4 system encountered in the Potash industry is included as part of the Potash add-on and is handled differently to the solubility of other species in SysCAD.

Please see Potash Solubility for more information.