Potassium cyanide

Potassium cyanide
Names
	IUPAC name Potassium cyanide
Identifiers
CAS Number	151-50-8 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:33191 ;
ChemSpider	8681 ;
ECHA InfoCard	100.005.267
EC Number	205-792-3;
PubChem CID	9032;
RTECS number	TS8750000;
UNII	MQD255M2ZO ;
UN number	1680
CompTox Dashboard (EPA)	DTXSID0024268 ;
	InChI InChI=1S/CN.K/c1-2;/q-1;+1 Key: NNFCIKHAZHQZJG-UHFFFAOYSA-N ; InChI=1/CN.K/c1-2;/q-1;+1 Key: NNFCIKHAZHQZJG-UHFFFAOYAH;
	SMILES [K+].[C-]#N;
Properties
Chemical formula	KCN
Molar mass	65.116 g·mol−1
Appearance	White crystalline solid ; deliquescent
Odor	faint, bitter almond-like
Density	1.52 g/cm3
Melting point	634.5 °C (1,174.1 °F; 907.6 K)
Boiling point	1,625 °C (2,957 °F; 1,898 K) at 101.3 kPa
Solubility in water	71.6 g/100 ml (25 °C (77 °F; 298 K)); 100 g/100 ml (100 °C (212 °F; 373 K));
Solubility in methanol	4.91 g/100 ml (20 °C (68 °F; 293 K))
Solubility in glycerol	soluble
Solubility in formamide	14.6 g/100 ml
Solubility in ethanol	0.57 g/100 ml
Acidity (pKa)	11.0
Magnetic susceptibility (χ)	37.0×10−6 cm3/mol
Refractive index (nD)	1.410
Thermochemistry
Std molar; entropy (S⦵298)	127.8 J⋅K−1·mol-1
Std enthalpy of; formation (ΔfH⦵298)	−131.5 kJ⋅mol−1
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H290, H300+H310+H330, H372, H410
Precautionary statements	P234, P260, P262, P264, P270, P271, P273, P280, P284, P301+P310+P330, P302+P350, P304+P340+P310, P307+P311, P314, P362, P390, P391, P403+P233, P405, P501 Preview warning: Omit Rules: keep P234, omit P406
NFPA 704 (fire diamond)	4 0 1
Flash point	Non-flammable
Threshold limit value (TLV)	5 mg/m3 (TWA), 5 mg/m3 (skin) (C)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	5 mg/kg (oral, rabbit); 10 mg/kg (oral, rat); 5 mg/kg (oral, rat); 8.5 mg/kg (oral, mouse);
	NIOSH (US health exposure limits):
PEL (Permissible)	5 mg/m3 (TWA, skin)
REL (Recommended)	5 mg/m3 (ceiling, 4.7 ppm, 10-minute)
IDLH (Immediate danger)	25 mg/m3
Safety data sheet (SDS)	ICSC 0671
Related compounds
Other anions	Potassium cyanate; Potassium thiocyanate;
Other cations	Hydrogen cyanide; Lithium cyanide; Sodium cyanide; Rubidium cyanide; Caesium cyanide;
Related compounds	Acetonitrile
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Potassium cyanide is a compound with the formula KCN. It is a colorless salt, similar in appearance to sugar, that is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications include chemical gilding and buffing of jewelry. Potassium cyanide is highly toxic, and a dose of 200 to 300 milligrams will kill nearly any human.

The moist solid emits small amounts of hydrogen cyanide due to hydrolysis (reaction with water). Hydrogen cyanide is often described as having an odor resembling that of bitter almonds.

The taste of potassium cyanide has been described as acrid and bitter, with a burning sensation similar to lye. However, potassium cyanide kills so rapidly its taste has not been reliably documented. In 2006, an Indian man killed himself using potassium cyanide. In the suicide note he left, the final words written were that potassium cyanide "burns the tongue and tastes acrid".