Small yellow crystals

Potassium ferrocyanide (K₄Fe(CN)₆·3H₂O), also known as yellow prussiate of potash or potassium hexacyanoferrate(II), is a coordination compound forming lemon-yellow monoclinic crystals at room temperature and decomposing at its boiling point. It is insoluble in alcohol but a litre of water can dissolve just under three hundred grams of the crystals, and the solution can react with acid to release hydrogen cyanide gas. The resulting hydrogen cyanide (HCN) boils at 26 °C and, being slightly lighter than air, quickly evaporates clear of the release point. Synthesis of copper(II)-tetraphenylporphine, a metal complex, from tetraphenylporphine and copper(II) acetate monohydrate. ... In crystallography, the monoclinic crystal system is one of the 7 lattice point groups. ... Quartz crystal In chemistry and mineralogy, a crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ... To meet Wikipedias quality standards, this article may require cleanup. ... Ethanol, also known as ethyl alcohol or grain alcohol, is a flammable, colorless, mildly toxic chemical compound with a distinctive perfume-like odor, and is the alcohol found in alcoholic beverages. ... BIC pen cap, about 1 gram. ... Hydrogen cyanide is a chemical compound with chemical formula HCN. A solution of hydrogen cyanide in water is called hydrocyanic acid or Prussic acid. ... Celsius is, or relates to, the Celsius temperature scale. ... The expression lighter than air refers to objects, usually aircraft, that are buoyant in air because they have an average density that is less than that of air (usually because they contain gases that have a density that is lower than that of air). ... This article or section is in need of attention from an expert on the subject. ...

On February 20, 2002 four Moroccans were arrested while in possession of detailed maps of the United States embassy in Rome, the Rome water supply network, and four kilograms of potassium ferrocyanide. This chemical is almost non-toxic itself and when combined with ferric salts it forms the Prussian blue, which is sometimes used as an antidote, but it will release the extremely toxic Hydrogen cyanide when combined with stronger acids. February 20 is the 51st day of the year in the Gregorian Calendar. ... For album titles with the same name, see 2002 (album). ... Nickname: The Eternal City Motto: SPQR: Senatus PopulusQue Romanus Location of the city of Rome (yellow) within the Province of Rome (red) and region of Lazio (grey) Coordinates: Region Lazio Province Province of Rome Founded 21 April 753 BC Mayor Walter Veltroni Area    - City 1,285 km²  (496. ... A sample of Prussian blue Prussian blue (Preußisch Blau, Berliner Blau) is a dark blue pigment used in paints and formerly in blueprints. ... Hydrogen cyanide is a chemical compound with chemical formula HCN. A solution of hydrogen cyanide in water is called hydrocyanic acid or Prussic acid. ...

See also

• ferrocyanide
• potassium ferricyanide
• Prussian blue

The ferrocyanide ion is Fe(CN)64-. Using IUPAC nomenclature, this would be called hexacyanoferrate(II) ion, but the old name is most common. ... Potassium ferricyanide (K3[Fe(CN)6]) also known as red prussiate, Prussian red or potassium hexacyanoferrate(III), is a coordination compound that is stable at room temperature and pressure and forms ruby red crystals and powder. ... A sample of Prussian blue Prussian blue (Preußisch Blau, Berliner Blau) is a dark blue pigment used in paints and formerly in blueprints. ...

External links

• National Pollutant Inventory - Cyanide compounds fact sheet

• Links to external chemical sources.