Gold Potassium Cyanide

Description

Gold Potassium Cyanide

Potassium cyanide 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 also 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.

Structure of Potassium Cyanide

In an 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 also vice versa. Despite the cyanide ions being diatomic, and thus less symmetric than the 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

Applications

KCN and sodium cyanide (NaCN) are widely used in organic synthesis for the preparation of nitriles and carboxylic acids, particularly in the von Richter reaction. It also finds use for the synthesis of hydantoins, which can be useful synthetic intermediates, when reacted with a carbonyl compound such as an aldehyde or ketone in the presence of ammonium carbonate.

KCN is used as a photographic fixer in the wet plate collodion process. The KCN dissolves silver where it has not been made insoluble by the developer. This reveals and stabilizes the image, making it no longer sensitive to light. Modern wet plate photographers may prefer less toxic fixers, often opting for the less toxic Sodium thiosulphate, but KCN is still used.

Chemical Structure

Main article:
In gold mining, KCN forms the water-soluble salt potassium gold cyanide and potassium hydroxide from gold metal in the presence of oxygen (usually from the surrounding air) and also water:

4 Au + 8 KCN + O2 + 2 H2O → 4 K[Au(CN)2] + 4 KOH
A similar process uses NaCN to produce sodium gold cyanide (NaAu(CN2)).

A New Process for Making this Medicine from Gold Particles:
The practical feasibility of a process involving the reaction of oxygen with gold particles in a potassium cyanide solution to produce potassium gold cyanide has been explored. The influence of temperature, cyanide concentration, and particle size on the gold dissolution was studied. The experimental results suggest that the rate is limited by the diffusion of oxygen to the gold surface. Gold particles (size between 230 and 325 mesh) can be converted with oxygen to potassium gold cyanide in less than two hours in 2 M KCN solution at 60°C. The implementation of a closed cyanide loop process is also discussed.

Appearance

This is an odorless white powder.

Solubility

It is highly soluble in water with a value of 140 g/l.

Synonyms

Kaliumgoldcyanid, Kálium-arany-cianid, potassium bis(cyano-kappaC)aurate(1-), Potassium dicyanoauate, potassium dicyanoaurate, Potassium dicyanoaurate(I), potassium gold(1+) dicyanide, Potassiumdicyan

Uses

It is used in electroplating and in photography. This metal is widely used in organic synthesis for the preparation of nitriles and also carboxylic acids. It is also largely utilized in the extraction of gold and silver from ores and also as a fumigant and insecticide.

Buy Potassium Gold Cyanide Online at POWERALL EMPORIUM

Price:
5 Grams = $400 USD