Jamison Ward

Hi Jia, Thank you very much again for your assistance. I was able to add my citric acid species to the basis in React! As you pointed out, the problem was that I needed to make a copy of the original thermo.com.V8.R6+ dataset and then add my citric acid species. For some reason, the program was not recognizing my custom species when I simply added them to the original dataset. Best, Jamison

Hi Jia, Thanks for your detailed reply. The log K of 200 at 25C is just a placeholder until I can get my citric acid reagent to appear in the React Basis. I tried restarting my computer, but I am still unable to swap my citric acid reagent in for HCO3- in the React Basis; even when clicking on the "Aqueous..." option, it does not appear in the list of species. Do I need to add the citric acid as an aqueous species in the thermo database I am editing? I tried this earlier, but I received a "circular reaction" warning since I already had the 3 deprotonated species entered as aqueous species. I also do not see an option to decouple my citric acid reagent from HCO3- in the "Config" -> "Redox couples..." window. Sincerely, Jamison

Hello, I'm attempting to use GWB to model a solution of lead(II) citrate exposed to atmospheric conditions. I see that citrate is not contained within the thermo.com.V8.R6+ database, so I've attempted to add all 4 species of this triprotic organic acid (citric acid, citric acid monobasic, citric acid dibasic, and citrate) to the database; however, I can't get my species to appear when I try to run a simulation in React. I've added citric acid as a redox species by the reaction: Citric_acid(aq) + 2 H2O + 4.5 O2(aq) = 6 H+ + 6 HCO3-, but I do not know the reaction's logK. Additionally, I've added each of the 3 deprotonated forms of the acid as aqueous species defined by the appropriate deprotonation reactions whose logK values are known. This seems to be the same approach that was used to add other organic acids to this thermo database such as acetic acid. I'm not sure why I can't swap in my Citric_acid(aq) reagent for HCO3- in React as I can for other organic acids such as acetic acid. I've attached the version of the thermo.com.V8.R6+ database file I've modified with my citric acid additions. Thank you for any assistance you can provide. Best, Jamison thermo.com.V8.R6+.tdat

Hi Jia, Thanks so much for your assistance! Using a combination of data from React and Rxn as you described, I was able to create my desired plot in Excel. Best, Jamison

Hello, I would like to know if it is possible to plot reaction free energy as a function of a system parameter, such as oxygen fugacity. For example, I am using Rxn to calculate the free energy of the reaction: H2(aq) + .5 O2(g) = H2O at a specified temperature, pH, reactant activities, and ionic strength. Running the program, I obtain a reaction free energy once I have specified all the parameters. However, I would like to see how the reaction free energy changes as I slide the oxygen fugacity. I tried using React to plot reaction free energy versus sliding oxygen fugacity, but I could not find a parameter for reaction free energy. Is it possible to use GWB to generate a plot as I have described? Thanks in advance, Jamison Hydrogen Oxidation.rxn