Hello all,
I am using React to model the dissolution of NdPO4 (input as reactant) under atmospheric conditions (fixed fugacities, fixed pH). The pH is adjusted with HNO3, therefore the NO3- concentration.
With the input shown in the attached file "Dissolution pH 5" the program runs without any problems.
In the next step, I would like to model the similar process at pH 10, again in atmospheric conditions. Here, of course, the pH would be adjusted via e.g. NaOH. I tried a few things, e.g. swapping H+ <-> OH- but somehow it will not work (see attachment Dissolution pH 10). Here, I set the OH- activity to 0.01 and this gives a pH of 10, although a a pH of 12 should be expected; especially if one looks at the OH- concentrations, e.g. after step 100 (= 0.016 mol/kg).
Has anyone experience how I can input correctly the fixed pH of 10 while having normal atmospheric conditions?
Thanks in advance for the help.
Kind regards,
Flipper78