Pourbaix diagram of Cu

[kelvin]

Dear Tom:

 

I have problem about Eh-pH diagram for my case(Please see the attachments).

 

My questions is as follows:

 

Why CuCl3-- species boundary display discontinuously ?

 

Regards,

 

Kelvin

Pourbaix diagram of Cu.ppt

case1.ac2

[mschock]

I have not run into this specific problem in my own modeling of copper with Act2, but with other software and when trying to do Pourbaix diagrams manually, I have run into similar problems when the Gibbs free energies used for the different species are taken from various different articles and compilations, and they not internally-consistent. The phase stability polygons then do not properly close.

[kelvin]

Dear Tom:

 

Could you tell me what happen about my question?

 

Regard,

 

Kelvin

[Tom Meuzelaar]

Dear Tom:

 

Could you tell me what happen about my question?

 

Regard,

 

Kelvin

 

Hi Kelvin:

 

Equilibrium constants for CuCl3- and CuSO4(aq) are only defined at 25C, thus you should either define solubility data for the temperatures you are working at or turn the extrapolate variable off.

 

Hope that helps,

 

Tom Meuzelaar

RockWare, Inc.

[Roger]

I have another query regarding Pourbaix diagrams for copper.

I'm looking at Cu pipe in water, and my question is do I use Cu metal or rather Cu++ as the diagram species?

It makes a significant difference to the resulting Pourbaix diagram.

Many thanks

Roger

[Guest Melika Sharifi]

Dear Roger,

 

To make your diagram, I believe all you need is Cu++ or Cu+ (depending on which thermo dataset you are using) as the main species. However, you can check your simulated environment by going to the “plot” plane à “view results” to see all the reactions and the activity of species in your system.

 

Please let me know if I can help you with anything else.

 

Best Regards,

 

Melika Sharifi

Aqueous Solutions LLC

Maker of The Geochemist's Workbench