Limiting Conductivities and Ion Association in Aqueous NaCF<sub>3</sub>SO<sub>3</sub> and Sr(CF<sub>3</sub>SO<sub>3</sub>)<sub>2</sub> from (298 to 623) K at 20 MPa. Is Triflate a Non-Complexing Anion in High-Temperature Water?
Bibliographic record
Abstract
Frequency-dependent electrical conductivities of solutions of aqueous sodium trifluoromethanesulfonate (“triflate”) and strontium triflate have been measured from T = 298 K to T = 623 K at p = 20 MPa, over a very wide range of ionic strength [(2·10 –5 to 0.35) mol·kg –1 ], using a unique high-precision flow-through AC electrical conductance instrument. Experimental values for the equivalent conductivity, Λ, of each electrolyte were used to calculate their equivalent conductivities at infinite dilution, Λ°, with the Turq–Blum–Bernard–Kunz (TBBK) ionic conductivity model. Values were derived for the limiting equivalent conductivity of the triflate ion, λ°(CF 3 SO 3 – ), and the strontium ion, λ°(Sr 2+ ). The TBBK fits to the concentration-dependent equivalent conductivity data for both NaCF 3 SO 3 and Sr(CF 3 SO 3 ) 2 required statistically significant ionic association constants for the species NaCF 3 SO 3 0 at temperatures T > 448 K, SrCF 3 SO 3 + at T > 448 K, and for Sr(CF 3 SO 3 ) 2 0 at T > 548 K. The stepwise association constants, K A, for the charged species SrCF 3 SO 3 +, were found to be greater or equal to than the ones for the neutral species Sr(CF 3 SO 3 ) 2 0 . The experimental value of K A for Sr(CF 3 SO 3 ) 2 0 was found to be similar to that for NaCF 3 SO 3 0 at 548 K but increased more steeply with temperature. At temperatures above 548 K, association constants derived from the concentration-dependent equivalent conductivities were increasingly sensitive to the assumptions used to calculate solution densities. Procedures for minimizing these effects are reported. The temperature dependence of the experimental association constants and limiting equivalent conductivities from (298 to 623) K could be represented accurately as functions of solvent density and viscosity, respectively.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.002 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.004 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".