The data are entered in a series of fields, and options are set using radio buttons or check boxes.
The model will check that the values that are input do not exceed internally set upper limits of molality (if they are, an explanatory messge will be written to the screen.)
The presence of aqueous phase ammonia (NH3) as a species in the model allows calculations for systems in which the total ammonia present (NH4+ + NH3) is only partially neutralised by H+, thus leaving an excess of NH3. Parameters for interactions between ions and NH3 ("salting in" and "salting out" effects) are included in the model, and provide an improved treament of the effects of solution composition and concentration on ammonia dissociation in the aqueous phase, and on its calculated equilibrium vapour pressure.
Pressing the "Show Options" button displays additional controls that affect the calculation, but which may be of interest to only small numbers of users. Option (1) allows water dissociation (H2O = H+ + OH−) to be switched off. The reaction only affects speciation and phase partitioning over a limited range of pH (i.e., close to neutral), and therefore may not have a significant effect in many calculations.
There are no gas input options.
There are no solids input options.