Simple La3+, LaOH2+, La(OH)2+, La(OH)3 speciation diagram

[Kaizen]

Hi, 

I am trying to generate a simple La3+, LaOH2+, La(OH)2+, La(OH)3 speciation diagram in React but so far I have been unsuccessful with my approach (attached).  Eventually, I want to be able to add in other species.  So guidance on this 101 problem will be very much appreciated.  

Many thanks!

 

La React file.rea

[Jia Wang]

Hello Kaizen,

I took a look in your input file and here are a couple of suggestions. To look at the speciation of La+++, you would need to add the species and the associated Log Ks for the reactions into the database. Without your thermo file, I am guessing that you might want to check whether or not the species you are interested in are all there and double check the Log K values. Please refer to section 9.2.3 in the GWB Essentials Guide for more information.

React defaults to using Cl- as the balancing species but in this case you might not need to have a charge balancing species since you are generating a speciation diagram. You can turn off balance species by clicking on the units of a species and select do not balance. You can then eliminate Cl- from your basis pane.

Lastly, note that La(OH)3 is a mineral in the thermo.V8.R6+.tdat database. If the mineral precipitates, you will be able to see its calculated quantity under the variable type: ‘Mineral’ and not under ‘Species concentration’.  

Hope this helps.

Best,

Jia Wang