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Showing results for tags 'ph'.
Found 5 results
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Hello, I was trying to make a redox diagram for NO3 with 12 samples I have input into GSS. I have watched the video tutorial and was unsure what the activity should be and how they knew what values to put in. Clarification on what the activity value refers to would be appreciated. I am unsure if it is a standard value for each element (Ex: SeO3 is always 1.0e-6 and U++++ is always 10.0) or if it changes. Thanks, Ashley
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Hi, I am trying to model calcite dissolution in DI water open to the atmosphere. My model is nearly correct except that the initial pH is only reaching about 9.6 when I need it to be reaching about 10 initially. I believe that the problem may stem from my basis fugacity of CO2 in the system. Currently it is set to log fugacity of -3.5 but since the water I use for the experiment comes from a jug, is it possible that the initial fugacity of water is lower? Or, is it possible that the fugacity of CO2 in the kinetic reaction should be set to a different value other than log fugacity of -3.5? I have tried playing with these values but was unable to achieve a higher initial pH. I have attached my expiremental results as well as my model. Let me know if you have any suggestions of how to raise the initial pH of the solution. Thank you, Robin Calcite only.rea Calcite Expiremental.xlsx
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Hello Admin, if i am interested in a fO2-pH Predominance diagram of Fe of a speculated fluid with for example the following parameters: H2ASO4 as As = 50 mg/l SO4-- as S = 50 mg/l Fe++ as Fe = 10 mg/l Na++ = 39.34 g/kg Cl- = 60.66 g/kg T = 150 °C ive been using GSS to calculate the activities of specific species which i applied in Act2. For the GSS calculations i did not input any pH value since it will be my x-axis on my diagram. Now my question is if that is the correct procedure since of course using specific pH values in GSS gives me different activities of my species and thus greatly altering the predominance diagram in the end? For what pH or in general for what terms do the activities calculated in GSS apply if no pH is entered? Sincerely Manuel
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I'm attempting to evaluate sorption of several parameters over a range of pH. I attempted to use the "slide" feature in react to do this: the initial solution has a pH of 4, and I slide it to 10. Precipitation is disabled. In this case, at pH 7.3, U is sorbed 99.48%. Great. if I run this same model, instead over the range of 7-10, U is sorbed 12.8% at pH 7.3. I would expect to get similar sorbed fractions at each pH, regardless of the start and end point. I'm expecting that these models should have the same results at every pH. I'm afraid I'm missing something fundamental about how the "slide" function works - what am I missing? Thanks! Clark 20170616_U_Sorption_2005_pH4.rea 20170616_U_Sorption_2005_pH7.rea FeOH_minteq_plusU.sdat
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Hello, I am trying to plot a speciation diagram with Fe(II) in solution over a wide range of pH. The plot essentially needs to be a concentration (of various Fe(II) species) v pH. I watched a tutorial video on youtube which goes over doing such a plot with the React module. (link below) However, since I have the student edition, this module is not available. I would like to know if this sort of a diagram can be constructed with the modules that come with the student edition. I have already tried the specE8 module. However, this lets me specify only one pH at a time. Would it be okay to use this module to run the speciation multiple times at various pH and then use another graphing software to plot the numbers I get after every individual iteration? Any help is appreciated. Thanks in advance! Youtube link with speciation tutorial using React module:
