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Select the compounds you wish to investigate

   Oxides     Chlorides     Carbides     Sulphides     Nitrides

Click metallic elements on the periodic table you wish to investigate. (max 2)





After selecting the type of compound and element(s) you wish to investigate click on 'See Ellingham diagram' button.
In addition to 2 metallic elements you may also select C and / or H.

The Ellingham diagram on the next page will show the graphs for the elements chosen.

To view the data on the right hand side of the page click on a line, then move the scrollbar slider to view data.

In addition this will display 1 or 2 other activities
 (a) opportunity to view non-standard data - fill in activity of element in the blue box and press 'Enter'
 (b) if an oxide system was selected then a 'Construct' button will appear. Clicking this will construct a line from (0,0) through the crosshair and indicate the partial pressure of oxygen under these conditions.


Click on the 'Construct' button to see determination of partial pressure of oxygen

Standard Free Energy / kJ mol-1 0 -250 -500 -750 -1000 -1250 -1500 0 500 1000 1500 2000 Temperature / K


Click on a line and use the scrollbar to see this data

Temperature / K

Equilibrium constant, Kc

Line equation

Free energy, ΔG / kJ mol-1

Equilibrium partial
pressure reacting gas,
pO2 / log bar

pH2 / pH2O

pCO / pCO2

To calculate ΔG for
non-standard state.
Enter activity of metal.
Press 'Compute'