Bibliographic record
Abstract
[13718-66-6] FeK2O4 (MW 198.05) InChI = 1S/Fe.2K.4O/q;2*+1;;;2*-1 InChIKey = ICBFRPYDFGVTEQ-UHFFFAOYSA-N (selective oxidant for alcohols and amines1) Solubility: sol water; insol typical organic solvents. Form Supplied in: violet solid; typical impurities present include potassium chloride and iron(III) oxide. Analysis of Reagent Purity: analysis of K2FeO4 by chromite ion has been reported.2 The ferrate concentration may be determined by measurement of the absorption band at 510 nm.3 Preparative Methods: NaOCl (20 g) is added to a solution of NaOH (30 g in 75 mL H2O) while keeping the solution temperature under 20 °C. Solid NaOH (70 g) is added with stirring, while maintaining the solution temperature at 25–30 °C, the solution cooled to 20 °C and filtered. Fe(NO3)3ċ9H2O (25 g) is added slowly, and the solution saturated with NaOH while being kept at 30 °C. After filtration, the filtrate of sodium ferrate is placed in a 20 °C bath and treated with saturated aqueous KOH (100 mL), stirred for 5 min, and filtered. The precipitate is washed several times with 10 mL portions of 3 M KOH into 50 mL of chilled saturated KOH solution, and a further 50 mL of chilled saturated KOH solution added to the washings. After stirring for 5 min, the solution is filtered, and the precipitate washed with benzene (10 mL) and several times with ethanol (20 mL). The precipitate is stirred with ethanol (1 L) for 20 min and the ethanol removed by filtration; this process is repeated three times. The precipitate is finally washed with Et2O under a drying tube, and drying continued in a vacuum desiccator.4 Handling, Storage, and Precautions: dry K2FeO4 is stable and should be stored in a desiccator. K2FeO4 is very unstable in acidic solutions, but decomposes only slowly in basic solutions.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.047 | 0.031 |
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; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".