Calc.  SED & PREDOM / SED

A fraction diagram shows the species distribution for a given chemical component. Fraction values go from zero to one (0% to 100%) and are usually plotted against a free concentration. Example for the system H+, CO32−:

Fraction diagram

This diagram was obtained with the following input file:

2 4 0 0
H+, CO3-2
OH-,     -14.0 -1 0
CO2(g),   18.16 2 1
H2CO3(aq),16.68 2 1
HCO3-,    10.33 1 1
CO3-2,  H+,
LAV, -5.0 -11.0, T, 0.01