Hydrocyanic acid

Hydrogen cyanide (HCN) hydrocyanic acid; colorless liquid, temperature boiling 25,7°, water solutions smell of bitter almonds. Is released during the hydrolysis of amygdalin contained in seeds, almonds, cherries, etc.
Hydrocyanic acid and its soluble salts (cyanide) is fast, strong poisons (lethal dose to humans by ingestion of 0.05 g). To open hydrocyanic acid solution alkalinized and add 1-2 drops of solution FeSO4. After acidification with hydrochloric acid in the presence of hydrocyanic acid occurs blue colouring (Prussian blue). Assistance "in case of poisoning cyanide, and its salts - see Cyanide compounds.