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# c.trivelpiece

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1. ## LLNL log K's

Thanks, Brian, for the responses. Between your guidance here and the help of a colleague, I think I have this pinned down now. I'm calculating the enthalpies of the reactions and using the van't Hoff equation to find the log k's. For the purpose of what I'm trying to do, I'm assuming a constant delH0f over the temperature range I'm interested in. I was able to find access to the book you suggested, but found similar texts and they were very helpful. Thanks, again.
2. ## LLNL log K's

Ok...so after some more reading, I think I've realized where I've gone wrong. Are the log k's given for the aqueous species in the database calculated from the delG0's for the reactions (involving the basis species) and NOT DIRECTLY from the delG0f's? So, delG0-reaction = SUM (delG0f-products) - SUM (delG0f-reactants)?? If this is the case, then I understand where my large discrepancies were coming from and I believe that I can calculate the values at different temperatures by the simple method I described in the first post. Sorry for the confusion on my end....if what I wrote here is corr
3. ## LLNL log K's

Hello, I'm looking for some help reconciling (or understanding) log K values for aqueous species with values I'm calculating from various references (Solutions, Minerals, and Equilibria - Garrels and Christ; Chemistry of Glasses - A. Paul). (As a disclaimer - my formal training is in nuclear science and I have little academic training in geochemistry, environmental chemistry or physical chemistry - and I'm hoping I'm just missing something about how these values are calculated.) For instance, the value for Zr++++ is set to log K (25°C) = -0.2385 in the thermo database, and there are no ot
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