Hydrogen cyanide boiling point

If hydrogen cyanide (HCN), the reactive compound in Zyklon B, were only bound to the walls by adsorption (adhesion),313 there would not be any detectable residues today anymore, due to the volatility of hydrogen cyanide (boiling point 25.7°C) all the hydrogen cyanide involved would long since have evaporated. 

Hydrogen cyanide (melting point -14°C, boiling point 26°C) is manufactured by the reaction of natural gas (methane), ammonia, and air over a platinum or platinum-rhodium catalyst at elevated temperature (the Andrussow process). 

In a typical process adiponitrile is formed by the interaction of adipic acid and gaseous ammonia in the presence of a boron phosphate catalyst at 305-350°C. The adiponitrile is purified and then subjected to continuous hydrogenation at 130°C and 4000 Ibf/in (28 MPa) pressure in the presence of excess ammonia and a cobalt catalyst. By-products such as hexamethyleneimine are formed but the quantity produced is minimized by the use of excess ammonia. Pure hexamethylenediamine (boiling point 90-92°C at 14mmHg pressure, melting point 39°C) is obtained by distillation, Hexamethylenediamine is also prepared commercially from butadience. The butadiene feedstock is of relatively low cost but it does use substantial quantities of hydrogen cyanide. The process developed by Du Pont may be given schematically as ... 

Hydrogen cyanide (prussic acid) is a liquid with a boiling point of 26°C. Its vapour is flammable and extremely toxic. The effects of acute exposure are given in Table 5.34. This material is a basic building block for the manufacture of a range of chemical products such as sodium, iron or potassium cyanide, methyl methacrylate, adiponitrile, triazines, chelates. 

On reaction with chlorine, hydrogen cyanide gives cyanogen chlorides, forming a trimer—cyanuric chloride (XII). The latter is a liquid with a melting point of 146°C and a boiling point of 196°C. Next, cyanuric triazide (XI) is obtained by the action of sodium azide in an aqueous solution, at room temperature on compound (XII). 

Acrylonitrile (2-propenonitrile, propene nitrile, vinyl cyanide, CH2=CHCN freezing point -83.5°C, boiling point 77.3°C, density 0.806) used to be manufactured completely from acetylene by reaction with hydrogen cyanide. 

Methyl methacrylate (melting point -48°C, boiling point 100°C, density 0.9394, flash point 9°C) is produced by the acetone cyanohydrin process in which the acetone cyanohydrin (from the reaction of acetone with hydrogen cyanide, q.v.) is reacted with sulfuric acid to yield methacrylamide sulfate, which is further hydrolyzed and esterified. The process is continuous. 

Hydrogen cyanide is a colorless, poisonous liquid with a boiling point of 25.1° C (ATSDR 1997). Thus, at room temperature, hydrogen cyanide exists primarily as a gas. It has a faint odor of bitter almonds (ATSDR 1997), although not everyone is able to smell it (Hall and Rumack 1986). The chemical and physical properties of hydrogen cyanide are summarized in Table 6-1. 

Hydrogen cyanide (HCN) is also chemically identified by the synonyms formonitrile, prussic acid and hydrocyanic acid. The physicochemical properties most related to the biological activity and uses of HCN are summarized in Table 1. Notable with HCN is that it is a low boiling point liquid (26.5°C). Related to its low MW (27.04) it has a high vapor pressure (600 mm Hg at 20°C) and low vapor density (0.947 at 31°C), Thus,... 

Hydrogen cyanide (HCN) is a colorless liquid with a boiling point of 25.6°C. It is miscible with water, producing a weakly acidic solution. It is a highly toxic compound, but a very useful chemical intermediate with high reactivity. It is used in the synthesis of acrylonitrile and adiponitrile, which are important monomers for plastic and synthetic fiber production. 

Reacts with acids, acid salts, chlorates, nitrates, aliphatic amines, isocyanates, oleum. Decomposes above boiling point 442°F/227°C, forming lethal hydrogen cyanide gas. Avoid hot water and steam. Attacks mild (low carbon) steel, copper, and copper alloys. Thermal decomposition releases hydrogen cyanide gas. On small fires, use dry chemical powder (such as Purple-K-Powder), alcohol-resistant foam, or CO2 extinguishers. Water may cause foaming. 

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