Potassium hexacyanoferrate(III)
From Crystal growing
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Potassium hexacyanoferrate(III) | |
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Names: | potassium hexacyanoferrate(III) potassium hexacyanoferriate potassium cyanoferrite potassium ferricyanide red prussiate of potash prussian red |
Formula: | K3[Fe(CN)6] |
SMILES: | [C-]#N.[C-]#N.[C-]#N.[C-]#N.[C-]#N.[C-]#N.[K+].[K+].[K+].[Fe+3] |
Molar mass: | 329.247 g/mol |
Density: | 1.845 g/cm3 |
Crystal system: | monoclinic (α) a=7.058 Å, b=10.426 Å, c=8.401 Åα=90°, β=107.311°, γ=90° monoclinic (β) a=14.021 Å, b=10.401 Å, c=8.339 Åα=90°, β=107.21°, γ=90° orthorhombic (γ) a=13.4226 Å, b=10.3964 Å, c=8.3814 Åα=90°, β=90°, γ=90° |
Shapes: |
|
Color: | dark-red |
Melting point: | 300 °C573.15 K <br />572 °F <br />1,031.67 °R <br /> |
Decomposition point: | -173.15 °C100 K <br />-279.67 °F <br />180 °R <br /> (α) |
Refractive index: | 1.573 |
Magnetic properties: | paramagnetic χ=2.29 · 10-4cm³/mol |
Hardness: | relatively strong |
Toxicity: | non-toxic LD50=2970mg/kg |
Description
Precursors
Reaction between potassium ferrocyanide, hydrogen peroxide and sulfuric or hydrochloric acid
Chemical equation:
For preparation of
Add to the flask with potassium ferrocyanide solution hydrogen peroxide and then add small parts of acid with stirring until a precipitation forming will stop. For purifying compound from potassium salts add large amount of cold ethanol, isopropanol or toluene to solution, salt will settle to the bottom in the form of fine crystals or powder. Filter precipitate and wash it with small amount of the same solvent, then filter the solution and use it for crystal growing.100.00
g of potassium hexacyanoferrate(III) а 128.29
g of potassium ferrocyanide trihydrate
, 172.18
g of 3%
peroxide and 40.25
g of 37%
sulfuric or 29.93
g of 37%
hydrochloric acid is required.Influence of temperature
While temperature increasing or decreasing rapidly, strokes could be formed at crystal faces.Growing at higher temperature gives mostly polycrystalline.
Influence of impurities
Opacity of crystals is increasing with compound impurity.Notes
At sunlight and air oxygen solution decomposes with forming green precipitate which impairs growth. So make as saturated solution as possible and do not use if for growth for a long time-every next crystallization layer will become more dirty and deformed.Reacts with acids with hydrocyanic acid emission.
Storage conditions
Store in its original form or under several layers of varnish at average humidity and room temperature. Do not store in matchboxes or cotton wool and do not heat.Solubility
Temperature | гр/100,00 гр water | гр/100,00 гр methanol | гр/100,00 гр hydrazine | гр/100,00 гр dimethylformamide | гр/100,00 гр formamide |
---|---|---|---|---|---|
0°C273.15 K <br />32 °F <br />491.67 °R <br /> | 29.9 | ||||
10°C283.15 K <br />50 °F <br />509.67 °R <br /> | 38.3 | ||||
15°C288.15 K <br />59 °F <br />518.67 °R <br /> | ~42.4 | ||||
20°C293.15 K <br />68 °F <br />527.67 °R <br /> | 46.4 | 2 | |||
25°C298.15 K <br />77 °F <br />536.67 °R <br /> | 48.8 | 0.05 | 2.7 | ||
30°C303.15 K <br />86 °F <br />545.67 °R <br /> | 52.7 | ||||
40°C313.15 K <br />104 °F <br />563.67 °R <br /> | 59.5 | ||||
50°C323.15 K <br />122 °F <br />581.67 °R <br /> | ~65.2 | ||||
60°C333.15 K <br />140 °F <br />599.67 °R <br /> | 70.9 | ||||
70°C343.15 K <br />158 °F <br />617.67 °R <br /> | 77.5 | 0.31 | |||
80°C353.15 K <br />176 °F <br />635.67 °R <br /> | 81.8 | ||||
90°C363.15 K <br />194 °F <br />653.67 °R <br /> | ~86.7 | ||||
100°C373.15 K <br />212 °F <br />671.67 °R <br /> | 91.6 |
Gallery
Video
Sources
- R.A.Kiper Properties of compounds. Handbook
- Piece of Science blog
- B.Figgis, Crystal structures of the simple monoclinic and orthorhombic polytypes of tripotassium hexacyanoferrate(III)
- B.Figgis, Crystal structures of the simple monoclinic and orthorhombic polytypes of tripotassium hexacyanoferrate(III)
- J.Morioka, Crystal structures of the room and low-temperature phases of monoclinic potassium ferricyanide
Cyanides | |
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Hexacyanoferroates |
Potassium hexacyanoferrate(II) (K4[Fe(CN)6]) • Sodium hexacyanoferrate(II) (Na4[Fe(CN)6]) • Tripotassium-sodium hexacyanoferrate(II) (K3Na[Fe(CN)6]) |
Hexacyanoferriates |
Potassium hexacyanoferrate(III) (K3[Fe(CN)6]) |
Hexacyanocobaltates |
Potassium hexacyanocobaltate(III) (K3[Co(CN)6]) |
Hexacyanochromates |
Potassium hexacyanochromate(III) (K3[Cr(CN)6]) |
Nitroprussides |
Sodium nitroprusside (Na2[Fe(CN)5NO]) |
Complexes |
Cyanocobalamin (C63H88CoN14O14P) |