Hydrocyanic acid solution is water containing up to 5% dissolved hydrocyanic acid with the faint odor of almonds. HYDROGEN CYANIDE is toxic by inhalation and skin absorption. Prolonged exposure to low concentrations or short term exposure to high concentrations may result in adverse health effects. Its vapors are just barely lighter than air.
HCN is prepared from NaCN and H2SO4, and dried by passage through H2SO4 and over CaCl2, then distilled in a vacuum system and degassed at 77oK before use [Arnold & Smith J Chem Soc, Faraday Trans 2 77 861 1981]. Cylinder HCN may contain stabilisers against explosive polymerisation, together with small amounts of H3PO4, H2SO4, SO2, and water. It can be purified by distillaton over P2O5, then frozen in Pyrex bottles at Dry-ice temperature for storage. [Zeigler Org Synth Coll Vol I 314 1941, Glemser in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I pp 658-660 1963.] Liquid HCN, like liquid ammonia, evaporates very slowly since the latent heat of evaporation is high and keeps it in the liquid state because the temperature of the liquid is lowered to below its boiling point. EXTREMELY POISONOUS; all due precautions should be taken.
ChEBI: A one-carbon compound consisting of a methine group triple bonded to a nitrogen atom. Also known as formonitrile, hydrogencyanide and prussic acid,HCN is a highly toxic liquid that has the odor of bitter almonds and boils at 25.6 °C.
also known as hydrocyanic acid, prussic acid, and fonnonitrile, is a very poisonous colorless gas with a characteristic fragrance of bitter almonds. Small amounts of hydrogen cyanide derivatives in combination with glucose and benzaldehyde are found in nature in apricot,peach,cherry, and plum pits.It liquifies at 26°C (79 OF) and is soluble in water,alcohol,and ether. Hydrogen cyanide is usually sold commercially as an aqueous solution containing 2 to 10% hydrogen cyanide. HCN reacts with amines, oxidisers, acids, sodium hydroxide, calcium hydroxide, sodium carbonate, caustic substances, and ammonia. The aqueous solutions of hydrogen cyani dedecompose slowly to form anunonium formate. In some uses, it is preferable to generate hydrogen cyanide as needed, thus eliminating handling and storage problems.
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
HCN was first isolated from a blue dye, Prussian blue, in 1704. HCN is obtainable from fruits that have a pit, such as cherries, apricots, and bitter almonds, from which almond oil and flavouring are made. HCN is used in fumigating, electroplating, mining, and producing synthetic fibres, plastics, dyes, and pesticides. It also is used as an intermediate in chemical syntheses.
Besides, hydrogen cyanide is used in manufacturing cyanide salts, aerylonitrile,and dyes.It is also used as a horticultural fumigant.
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
This particular record contains hydrogen cyanide dissolved in water. Hydrogen cyanide is a very volatile liquid or colorless gas smelling of bitter almonds, b.p. 26° C. A deadly human poison by all routes. The gas (hydrogen cyanide) forms explosive mixtures with air, HYDROGEN CYANIDE reacts violently with acetaldehyde. HYDROGEN CYANIDE is a severe explosion hazard when heated or exposed to oxidizers. HYDROGEN CYANIDE may polymerize explosively at elevated temperature (50-60° C) or in the presence of traces of alkali [Wohler, L. et al., Chem. Ztg., 1926, 50, p. 761, 781]. In the absence of a stabilizer (e.g., phosphoric acid) HYDROGEN CYANIDE may undergo explosively rapid spontaneous (autocatalytic) polymerization leading to a fire. The reaction is autocatalytic because of ammonia formation. The anhydrous acid should be stabilized by the addition of acid. [Bond, J., Loss Prev. Bull., 1991, 101, p.3]. During the preparation of imidoester hydrochlorides, hydrogen chloride was rapidly passed over alcoholic hydrogen cyanide. An explosion ensued, even with cooling of the process, [J. Org. Chem., 1955, 20, 1573].