Spana  SPANA / Making a diagram

Example of a diagram where reversed concentration ranges are used. The diagram shows the species distribution for Fe3+ when chloride is exchanged for sulphate. Note that both Cl and SO42− are varied along the X-axis. The composition changes from 0.4 M HCl at the left of the diagram to 0.2 M H2SO4 at the right. The ionic strength is evaluated iteratively at each point.

Reverse_Concs_Diagr

This diagram was obtained with the following input file:

 4  16  4  0
H+, Fe+3, Cl-, SO4 2-
Fe(OH)2+  ,-5.67  -2 1 0 0  Fe(OH)3   ,-12.56 -3 1 0 0
Fe(OH)4-  ,-21.6  -4 1 0 0  Fe(SO4)2- , 5.38   0 1 0 2
Fe2(OH)2+4,-2.95  -2 2 0 0  Fe3(OH)4+5,-6.3   -4 3 0 0
FeCl 2+   , 1.48   0 1 1 0  FeCl2+    , 2.13   0 1 2 0
FeCl3     , 1.13   0 1 3 0  FeCl4-    ,-0.92   0 1 4 0
FeHSO4 2+ , 4.468  1 1 0 1  FeOH 2+   ,-2.19  -1 1 0 0
FeSO4+    , 4.04   0 1 0 1  H2SO4     , 0.0    2 0 0 1
HSO4-     , 1.98   1 0 0 1  OH-       ,-14.0  -1 0 0 0
Fe(OH)2.7Cl0.3(c),  3.04 -2.7 1 0.3 0
H3OFe3(SO4)2(OH)6(c),5.39 -5 3 0 2
Fe2(SO4)3(c), -3.58  0 2 0 3
Fe2O3(cr)   , -0.408 -6 2 0 0
Fe+3, EH, SO4 2-,
T,0.4   T,1E-05
TV,  0.4  0
TV,  0  0.2