Title: Carbon Monoxide
CAS Registry Number: 630-08-0
Molecular Formula: CO
Molecular Weight: 28.01
Percent Composition: C 42.88%, O 57.12%
Literature References: Produced on an industrial scale by partial oxidation of hydrocarbon gases from natural gas or by the gasification of coal and coke. Conveniently prepd in the laboratory by heating calcium carbonate with Zn dust: Weinhouse, J. Am. Chem. Soc. 70, 442 (1948); by dehydration of formic acid with H2SO4: Gilliland, Blanchard, Inorg. Synth. 2, 81 (1946). Purification of carbon monoxide bought in steel cylinders: A. Klemenc, Die Behandlung und Reindarstellung von Gasen (Vienna, 1948) p 160; Glemser in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) p 646. Review: R. Pierantozzi in Kirk-Othmer Encyclopedia of Chemical Technology vol. 5 (Wiley-Interscience, New York, 4th ed., 1993) pp 97-122. Review of clinical toxicology: Stewart, Annu. Rev. Biochem. 15, 409-423 (1975); D. Gorman et al., Toxicology 187, 25-38 (2003); of industrial toxicology: Patty's Industrial Hygiene and Toxicology vol. 2F, G. D. Clayton, F. E. Clayton, Eds. (Wiley-Interscience, New York, 4th ed., 1994) pp 4523-4552.
Properties: Highly poisonous, odorless, colorless, tasteless gas. Very flammable, burns in air with a bright blue flame. Ignition pt in air: 700°. mp -205.0°. bp -191.5°. d4-195 (liq) 0.814. d (gas) 0.968 (air = 1.000). d40 at 760 mm: 1.250 g/liter. The top pressure is 1500 psi. Flammable limits in air: 12 to 75 vol %. Crit press 35 atm, crit temp -139°. Heat capacity at 20°: 6.95 cal/mole/°C. Heat value per m3: 3033 kcal. Heat of formation: -26.39 kcal/mol. Dec into carbon and carbon dioxide between 400 and 700°, at lower temp when in contact with catalytic surfaces. Above 800° the equilibrium reaction favors CO formation. Hopcalite, a mixture of the oxides of manganese and copper, catalyzes the decompn at room temp, as does Pd on silica gel. Sparingly sol in water: 3.3 ml/100 ml H2O at 0°; 2.3 ml/100 ml H2O at 20°; freely absorbed by a concd soln of cuprous chloride in HCl or in NH4OH. Appreciably sol in some organic solvents, such as ethyl acetate, CHCl3, acetic acid. The soly in methanol and ethanol is about 7 times as great as the soly in water.
Melting point: mp -205.0°
Boiling point: bp -191.5°
Density: d4-195 (liq) 0.814; d (gas) 0.968 (air = 1.000); d40 at 760 mm: 1.250 g/liter
CAUTION: Combines with the hemoglobin in the blood to form carboxyhemoglobin which disrupts oxygen transport and delivery throughout the body. Potential symptoms of overexposure by inhalation are headache, tachypnea, nausea, vomiting, lassitude, fatigue, dizziness, confusion, hallucinations; dimness of vision; irritability, impaired judgement; cyanosis; depression of S-T segment of electrocardiogram, angina, syncope; coma. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 2003) p 54; Clinical Toxicology of Commercial Products, R. E. Gosselin et al., Eds. (Williams & Wilkins, Baltimore, 5th ed., 1984) Section III, pp 94-101.
Use: As reducing agent in metallurgical operations especially in the Mond process for the recovery of nickel; in organic synthesis especially in the Fischer-Tropsch processes for petroleum-type products and in the oxo reaction; in the manuf of metal carbonyls. |