Example 11. Log O2-fugacity diagram
Data for the chemical system H+, e−,
Fe2+ and HS−
was extracted using DATABASE, as for
example 6 but setting the
temperature to 300°C.
In SPANA the chemical system was
modified in to
exchange components for reactions,
in this case e− was exchanged for O2(g),
and HS− for H2S (without
a phase indicator, it means that
H2S is aqueous, dissolved).
By making O2(g) one of the components,
it is possible to make a diagram with
log PO2(g) in the vertical axis.
This type of diagrams is common in geochemistry. Note that fugacity and partial pressure
have the same relationship as activity and concentration.
See also: example 12 (another high-temperature diagram).
Back to: example files
