Potassium cyanide - wikipedia 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 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 65.12 g / mol Appearance White crystalline solid deliquescent Odor faint, almond - like Density 1.52 g / cm Melting point 634.5 ° C ( 1,174.1 ° F ; 907.6 K ) Boiling point 1,625 ° C ( 2,957 ° F ; 1,898 K ) Solubility in water 71.6 g / 100 ml ( 25 ° C ) 100 g / 100 mL ( 100 ° C ) Solubility in methanol 4.91 g / 100 mL ( 20 ° C ) Solubility in glycerol soluble Solubility in formamide 14.6 g / 100 mL Solubility in ethanol 0.57 g / 100mL Solubility in hydroxylamine 41 g / 100 mL Acidity ( pK ) 11.0 Magnetic susceptibility ( χ ) − 37.0 10 cm / mol Refractive index ( n ) 1.410 Thermochemistry Std molar entropy ( S ) 127.8 J K mol Std enthalpy of formation ( Δ H ) − 131.5 kJ / mol Hazards Safety data sheet ICSC 0671 GHS pictograms GHS signal word Danger GHS hazard statements H290, H300, H310, H330, H370, H372, H410 GHS precautionary statements P260, P264, P273, P280, P284, P301 + 310 NFPA 704 0 0 Flash point Non-flammable Lethal dose or concentration ( LD, LC ) : LD ( median dose ) 5 mg / kg ( oral, rabbit ) 10 mg / kg ( oral, rat ) 5 mg / kg ( oral, rat ) 8.5 mg / kg ( oral, mouse ) US health exposure limits ( NIOSH ) : PEL ( Permissible ) TWA 5 mg / m REL ( Recommended ) C 5 mg / m ( 4.7 ppm ) ( 10 - minute ) IDLH ( Immediate danger ) 25 mg / m Related compounds Other anions Potassium cyanate Potassium thiocyanate Other cations Sodium cyanide Related compounds Hydrogen cyanide Except where otherwise noted, data are given for materials in their standard state ( at 25 ° C ( 77 ° F ), 100 kPa ). N verify ( what is ? ) Infobox references Potassium cyanide is a compound with the formula K CN. 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. Contents 1 Production 1.1 Historical production 2 Structure 3 Applications 3.1 Potassium gold cyanide 4 Toxicity 5 References 6 External links Production 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 + H O or by treating formamide with potassium hydroxide : HCONH + KOH → KCN + 2H O About 50,000 tons of potassium cyanide are produced yearly. Historical production 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 : K ( Fe ( CN ) ) → 4 KCN + FeC + N 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. 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. Potassium gold cyanide Main article : Potassium gold cyanide In gold mining, KCN forms the water - soluble salt potassium gold cyanide ( or gold potassium cyanide ) and potassium hydroxide from gold metal in the presence of oxygen ( usually from the surrounding air ) and water : 4 Au + 8 KCN + O + 2 H O → 4 K ( Au ( CN ) ) + 4 KOH A similar process uses NaCN to produce sodium gold cyanide ( NaAu ( CN ) ). Toxicity Main article : Cyanide poisoning Potassium cyanide is a potent inhibitor of cellular respiration, acting on mitochondrial cytochrome c oxidase, hence blocking oxidative phosphorylation. This prevents the body from oxidizing food to produce useful energy. Lactic acidosis then occurs as a consequence of anaerobic metabolism. Initially, acute cyanide poisoning causes a red or ruddy complexion in the victim because the tissues are not able to use the oxygen in the blood. The effects of potassium and sodium cyanide are identical, and symptoms of poisoning typically occur within a few minutes of ingesting the substance : the person loses consciousness, and brain death eventually follows. During this period the victim may suffer convulsions. Death is caused by cerebral hypoxia. The lethal dose ( human ) for potassium cyanide is 20 mg. Its toxicity when ingested depends on the acidity of the stomach, because it must react with an acid to become hydrogen cyanide, the deadly form of cyanide. Grigori Rasputin may have survived a potassium cyanide poisoning because his stomach acidity was unusually low. A number of prominent persons were killed or committed suicide using potassium cyanide, including members of the Young Bosnia and famous personalities in the Third Reich, such as Erwin Rommel, Hitler 's longtime companion Eva Braun, Joseph Goebbels, Heinrich Himmler, and Hermann Göring. World War II era British agents ( using purpose - made suicide pills ), computer scientist Alan Turing, polymer chemist Wallace Carothers, 19th - Century German chemist Viktor Meyer,, and various religious cult suicides such as by the Peoples Temple, Danish writer Gustav Wied in 1914, and members of the LTTE involved in the assassination of Indian prime minister Rajiv Gandhi. Jason Altom, who was a promising graduate student in the lab of Nobel - Prizewinning chemist EJ Corey at Harvard. Slobodan Praljak, a Wartime general in Republic of Croatia, committed suicide by drinking from a vial containing potassium cyanide during the reading of his sentence in The Hague on International Criminal Tribunal for the former Yugoslavia ( ICTY ) on 29 November 2017. It is used by professional entomologists as a killing agent in collecting jars, as insects succumb within seconds to the HCN fumes it emits, thereby minimizing damage to even highly fragile specimens. KCN can be detoxified most efficiently with hydrogen peroxide or with a solution of sodium hypochlorite. Such solutions should be kept basic whenever possible so as to eliminate the possibility of generation of hydrogen cyanide : KCN + H O → K OCN + H O References ^ Jump up to : `` NIOSH Pocket Guide to Chemical Hazards # 0522 ''. National Institute for Occupational Safety and Health ( NIOSH ). Jump up ^ `` Cyanides ( as CN ) ''. Immediately Dangerous to Life and Health Concentrations ( IDLH ). National Institute for Occupational Safety and Health ( NIOSH ). Jump up ^ http://cameochemicals.noaa.gov/chemical/5150 ^ Jump up to : Andreas Rubo, Raf Kellens, Jay Reddy, Joshua Wooten, Wolfgang Hasenpusch `` Alkali Metal Cyanides '' in Ullmann 's Encyclopedia of Industrial Chemistry 2006 Wiley - VCH, Weinheim, Germany. doi : 10.1002 / 14356007. i01_i01 Jump up ^ http://www.smh.com.au/news/world/suicide-note-reveals-taste-of-cyanide/2006/07/08/1152240534587.html Jump up ^ Online Mendelian Inheritance in Man ( OMIM ) 304300 Jump up ^ `` The only taste : Cyanide is acrid ''. hindustantimes.com. Hindustan Times. Jump up ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw - Hill, 2002, ISBN 0 - 07 - 049439 - 8 Jump up ^ Von Wagner, Rudolf ( 1897 ). Manual of chemical technology. New York : D. Appleton & Co. p. 474 & 477. Jump up ^ Crystallography Open Database, Structure of KCN Jump up ^ H.T. Stokes ; D.L. Decker ; H.M. Nelson ; J.D. Jorgensen ( 1993 ). `` Structure of potassium cyanide at low temperature and high pressure determined by neutron diffraction ''. Physical Review B. 47 ( 17 ) : 11082 -- 11092. doi : 10.1103 / PhysRevB. 47.11082... Jump up ^ J. Towler, MD. `` The Silver Sunbeam ( Facsimile 1864 edition, 1969 ) '' pg 119 Jump up ^ John Harris Trestrail III. Criminal Poisoning - Investigational Guide for Law Enforcement, Toxicologists, Forensic Scientists, and Attorneys ( 2nd edition ). pg 119 Jump up ^ John Emsley. The Elements of Murder : A History of Poison. pg 73 Jump up ^ http://listverse.com/2007/10/07/top-10-scientists-who-committed-suicide/ Jump up ^ `` War criminal ' took cyanide ' in Hague court ''. BBC News. 2017 - 12 - 01. Retrieved 2017 - 12 - 01. External links International Chemical Safety Card 0671 Hydrogen cyanide and cyanides ( CICAD 61 ) National Pollutant Inventory - Cyanide compounds fact sheet NIOSH Pocket Guide to Chemical Hazards CSST ( Canada ) NIST Standard Reference Database Institut national de recherche et de sécurité ( 1997 ). `` Cyanure de sodium. Cyanure de potassium ''. Fiche toxicologique n ° 111, Paris : INRS, 6pp. ( in French ) Potassium compounds KAsO KBr KBrO KCN KCNO KCl KClO KClO KClO KF KH KHCO KHCO KHF KHS KHSO KHSO KH AsO KH PO KH PO KI KIO KIO KMnO KN KNH KNO KNO KOCN KOH KO KPF KSCN KCH COO K Al O K CO K CrO K Cr O K FeO K HPO K MnO K O K O K PtCl K PtCl K SeO K SO K SO KHSO K S O K S O K S O K Po K SiO K ( Fe ( CN ) ) K ( Fe ( C O ) ) K ( Fe ( CN ) ) K PO K Mo Cl Molecules detected in outer space Molecules Diatomic Aluminium monochloride Aluminium monofluoride Aluminium monoxide Argonium Carbon monophosphide Carbon monosulfide Carbon monoxide Carborundum Cyanogen radical Diatomic carbon Fluoromethylidynium Hydrogen chloride Hydrogen fluoride Hydrogen ( molecular ) Hydroxyl radical Iron ( II ) oxide Magnesium monohydride cation Methylidyne radical Nitric oxide Nitrogen ( molecular ) Nitrogen monohydride Nitrogen sulfide Oxygen ( molecular ) Phosphorus monoxide Phosphorus mononitride Potassium chloride Silicon carbide Silicon mononitride Silicon monoxide Silicon monosulfide Sodium chloride Sodium iodide Sulfur monohydride Sulfur monoxide Titanium oxide Triatomic Aluminium hydroxide Aluminium isocyanide Amino radical Carbon dioxide Carbonyl sulfide CCP radical Chloronium Diazenylium Dicarbon monoxide Disilicon carbide Ethynyl radical Formyl radical Hydrogen cyanide ( HCN ) Hydrogen isocyanide ( HNC ) Hydrogen sulfide Hydroperoxyl Iron cyanide Isoformyl Magnesium cyanide Magnesium isocyanide Methylene radical Nitrous oxide Nitroxyl Ozone Phosphaethyne Potassium cyanide Protonated molecular hydrogen Sodium cyanide Sodium hydroxide Silicon carbonitride c - Silicon dicarbide SiNC Sulfur dioxide Thioformyl Thioxoethenylidene Titanium dioxide Tricarbon Water Four atoms Acetylene Ammonia Cyanic acid Cyanoethynyl Cyclopropynylidyne Formaldehyde Fulminic acid HCCN Hydrogen peroxide Hydromagnesium isocyanide Isocyanic acid Isothiocyanic acid Ketenyl Methylene amidogen Methyl radical Propynylidyne Protonated carbon dioxide Protonated hydrogen cyanide Silicon tricarbide Thioformaldehyde Tricarbon monoxide Tricarbon sulfide Thiocyanic acid Five atoms Ammonium ion Butadiynyl Carbodiimide Cyanamide Cyanoacetylene Cyanoformaldehyde Cyanomethyl Cyclopropenylidene Formic acid Isocyanoacetylene Ketene Methane Methoxy radical Methylenimine Propadienylidene Protonated formaldehyde Protonated formaldehyde Silane Silicon - carbide cluster Six atoms Acetonitrile Cyanobutadiynyl radical E-Cyanomethanimine Cyclopropenone Diacetylene Ethylene Formamide HC N Ketenimine Methanethiol Methanol Methyl isocyanide Pentynylidyne Propynal Protonated cyanoacetylene Seven atoms Acetaldehyde Acrylonitrile Vinyl cyanide Cyanodiacetylene Ethylene oxide Hexatriynyl radical Methylacetylene Methylamine Methyl isocyanate Vinyl alcohol Eight atoms Acetic acid Aminoacetonitrile Cyanoallene Ethanimine Glycolaldehyde Heptatrienyl radical Hexapentaenylidene Methylcyanoacetylene Methyl formate Propenal Nine atoms Acetamide Cyanohexatriyne Cyanotriacetylene Dimethyl ether Ethanol Methyldiacetylene Octatetraynyl radical Propene Propionitrile Ten atoms or more Acetone Benzene Benzonitrile Buckminsterfullerene ( C fullerene, buckyball ) C fullerene Cyanodecapentayne Cyanopentaacetylene Cyanotetra - acetylene Ethylene glycol Ethyl formate Methyl acetate Methyl - cyano - diacetylene Methyltriacetylene Propanal n - Propyl cyanide Pyrimidine Deuterated molecules Ammonia Ammonium ion Formaldehyde Formyl radical Heavy water Hydrogen cyanide Hydrogen deuteride Hydrogen isocyanide Methylacetylene Trihydrogen cation Unconfirmed Anthracene Dihydroxyacetone Ethyl methyl ether Glycine Graphene H NCO Linear C Naphthalene cation Phosphine Pyrene Silylidine Related Abiogenesis Astrobiology Astrochemistry Atomic and molecular astrophysics Chemical formula Circumstellar envelope Cosmic dust Cosmic ray Cosmochemistry Diffuse interstellar band Earliest known life forms Extraterrestrial life Extraterrestrial liquid water Forbidden mechanism Helium hydride ion Homochirality Intergalactic dust Interplanetary medium Interstellar medium Photodissociation region Iron -- sulfur world theory Kerogen Molecules in stars Nexus for Exoplanet System Science Organic compound Outer space PAH world hypothesis Panspermia Polycyclic aromatic hydrocarbon ( PAH ) RNA world hypothesis Spectroscopy Tholin Category : Astrochemistry Portal : Astrobiology Salts and covalent derivatives of the cyanide ion 5 6 7 8 9 10 11 12 13 14 15 16 17 18 HCN He LiCN Be ( CN ) NH CN OCN, - NCO FCN Ne NaCN Mg ( CN ) Al ( CN ) Si ( CN ), Me SiCN P ( CN ) SCN, - NCS, ( SCN ), S ( CN ) ClCN Ar KCN Ca ( CN ) Sc ( CN ) Ti ( CN ) V Cr ( CN ) Cr ( CN ) Mn ( CN ) Fe ( CN ), Fe ( CN ), Fe ( CN ) Co ( CN ), Co ( CN ) Ni ( CN ) Ni ( CN ) CuCN Zn ( CN ) Ga ( CN ) Ge As ( CN ) SeCN ( SeCN ) Se ( CN ) BrCN Kr RbCN Sr ( CN ) Y ( CN ) Zr ( CN ) Nb Mo ( CN ) Tc Ru ( CN ) Rh ( CN ) Pd ( CN ) AgCN Cd ( CN ) In ( CN ) Sn Sb ( CN ) Te ICN Xe CsCN Ba ( CN ) Hf Ta W ( CN ) Re Os ( CN ) Ir ( CN ) Pt ( CN ), Pt ( CN ) AuCN, Au ( CN ) Hg ( CN ), Hg ( CN ) TlCN Pb ( CN ) Bi ( CN ) Po At Rn Fr Ra Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og ↓ La Ce ( CN ), Ce ( CN ) Pr Nd Pm Sm Eu Gd ( CN ) Tb Dy Ho Er Tm Yb Lu Ac Th Pa UO ( CN ) Np Pu Am Cm Bk Cf Es Fm Md No Lr GND : 4163067 - 1 LCCN : sh85105605 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Potassium_cyanide&oldid=855649455 '' Categories : Cyanides Photographic chemicals Potassium compounds Hidden categories : Use dmy dates from June 2018 Articles without KEGG source Articles with changed EBI identifier ECHA InfoCard ID from Wikidata Chembox having GHS data Articles containing unverified chemical infoboxes All articles with unsourced statements Articles with unsourced statements from March 2016 Articles with French - 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Question: how long does it take potassium cyanide to kill you
Answer: within a few minutes of ingesting the substance