[How to calculate the pe to calculate the saturation index?]

Hi all,

I am trying to calculate the saturation index of galena in solution. In my project I mix 2mM Lead nitrate with 7.8 Na2S and adjust the pH to 5.5, I entered these numbers in geochemist's workbench and attached it to this message. But I do not know the pe number. Would you please check the file I attached to see if the what I have entered correct or not? So why galena is under saturation?

For example is it OK I swap s with SO4-2?

What about the pe?

 

Pb-S.sp8

[ACT2 Module - Stability Diagram]

Thanks a lot for your reply. I have some more questions so I am going to build another title. I hope to receive your guidance.

[ACT2 Module - Stability Diagram]

Hi, This topic was really helpful. I have a question I would appreciate if you could guide me. How could you calculate activity of Fe3+ and activity of SO42-?

[How to draw Pb-S porbaix diagram?]

Hi all,

I want to draw Pb-S pourbaix diagram. For example mixing 0.01mM Na2S and 1mM PbNO3 in water at 25C. I would appreciate if you could tell me the steps of drawing that diagram?