Negative pH?

[emarcuci]

Hi,

 

I was recently using React to speciate a fluid from an experimental analysis. Basically, I ran an experiment at elevated temperature, but pH and cation/anion fluid analysis were measured at room temperature. I use React to rebalance the fluid at the higher temperature; however, several of my experiments have negative pH (~-0.15). React did not seem to like that. When I tried to run the model, it would say that H+ activity was negative and not give any output. I am working with 1 M H2SO4, so the pH should be that low. Can React (and the other modules) not handle negative pH?

 

thank you,

Emma

[Tom Meuzelaar]

Hi Emma:

 

React can work with waters that have negative pH (see attached script), but I don't think it will take a negative pH as input. Instead, use the equivalent proton activity to constrain your model.

 

I hope that helps.

 

Tom Meuzelaar

RockWare, Inc.

[emarcuci]

Morning,

 

Thanks Tom! Entering as a concentration/activity solved the problem.

 

Emma