Structure and properties
Potassium cyanide (KCN, Mr = 65.1 g/mol) is the potassium salt of hydrocyanic acid (HCN) and exists as a white, crystalline solid that is readily soluble in water. Potassium cyanide has a pungent taste and smells like bitter almonds. Great care should be taken when handling the substance, as poisoning can occur rapidly. Structure: K+CN–
Effects
Potassium cyanide is a very potent poison that causes death rapidly – within minutes to hours – at a dose of 100 to 300 milligrams. Various antidotes such as hydroxocobalamin, amyl nitrite, sodium nitrite, and sodium thiosulfate are used to treat poisoning. The effects are based on the inhibition of the enzyme cytochrome c oxidase in the mitochondria. This blocks the respiratory chain and inhibits the formation of the energy carrier ATP. Potassium cyanide was formerly used as a drug, but is now obsolete and should not be used medicinally. Technical applications exist, for example, gold extraction.
Abuse
Cyanides have been used in the past for suicide, as weapons of war, and for murder.
