Potassium cyanide KCN
$400.00 – $1,350.00
ComparePotassium cyanide (KCN) is a compound with the formula KCN. This colorless crystalline salt, similar in appearance to sugar, is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications include jewelry for chemical gilding and buffing.
Potassium cyanide is highly toxic. The moist solid emits small amounts of hydrogen cyanide due to hydrolysis, which smells like bitter almonds.Not everyone, however, can smell this; the ability to do so is a genetic trait.
The taste of potassium cyanide has been described as acrid with a burning sensation.
KCN is produced by treating hydrogen cyanide with aqueous solution of potassium hydroxide, followed by evaporation of the solution in a vacuum:
HCN + KOH → KCN + H2O
or by treating formamide with potassium hydroxide:
HCONH2 + KOH → KCN + 2H2O
About 50,000 tons of potassium cyanide are produced yearly.
Prior to 1900, before the invention of the Castner process, potassium cyanide was the most important source of alkali metal cyanides.In this historical process, potassium cyanide was produced by decomposing potassium ferrocyanide:
K4[Fe(CN)6] → 4 KCN + FeC2 + N2
Structure
In aqueous solution, KCN is dissociated into hydrated potassium (K+) ions and cyanide (CN−) ions. The common form of solid KCN, stable at ambient pressure and temperature, has the same cubic crystal structure as sodium chloride, with each potassium ion surrounded by six cyanide ions, and vice versa. Despite the cyanide ions being diatomic, and thus less symmetric than chloride, they rotate so rapidly, their time-averaged shape is spherical. At low temperature and high pressure, this free rotation is hindered, resulting in a less symmetric crystal structure with the cyanide ions arranged in sheets.
Price for grams | 50g, 100g, 150g, 250g, 500g |
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