Alfisol, Item 007:

IExFit, version 3.4 Fit adsorption data based on ion exchange reaction models. Display solid & liquid & gas phase speciation diagrams as a funciton of pH & redox conditions.

Why models? Main Welcome Program Information Select File Control Center (CC) CC: Database

CC-1: Enter Ions Present CC-2: Enter Initial Conditions CC: Add Solids CC: Add Gases CC: Add Ion Adsorption Data CC: Add Ion-Exchange Model CC-3: Run Aqueous Speciation CC-3: Run Model Fit Optimization

Tab: Model Optimization Tab: Options Tab: f(pH) Mass Balance Tab: Adsorption Data Analysis Tab: f(pH) Adsorbed Tab: f(pH) Aqueous Tab: f(pH) Solids Tab: f(pH) Gases Tab: pe-pH Tab: Titration

Step 3: Run Aqueous Speciation - Tab: Titration

Click on the "Titration" tab to view display a titration simulation and analysis.

In the example below, 20 mM NaH2PO4 was in 30 mL container and titrated with 100 mM HCl and NaOH (shown in black).

The initial pH is given as pH 4.74 (zpt = zero point of titration).
The 1^st derivative (1/β) is also shown in green.
Analysis end points are shown in orange.

Note that although IExFit was asked to perform the analysis from pH 0 to 14, the analysis stopped short because the container size (or titrant volume) limitation was set to 30 mL maximum.