Title: Sulfuric Acid
CAS Registry Number: 7664-93-9
Additional Names: Oil of vitriol
Molecular Formula: H2O4S
Molecular Weight: 98.08
Percent Composition: H 2.06%, O 65.25%, S 32.69%
Line Formula: H2SO4
Literature References: Prepd by the Contact Process according to the reactions 2SO2 + O2 ® 2SO3, and SO3 + H2O ® H2SO4; by the Chamber Process according to the reactions 2NO + O2 ® 2NO2, and NO2 + SO2 + H2O ® H2SO4 + NO. Sulfuric acid of commerce contains 93-98% H2SO4; the remainder is water. Monograph: W. W. Duecker, J. R. West, The Manufacture of Sulfuric Acid (Reinhold, New York, 1959) 515 pp. Review of manuf: Pearce, "Sulphuric Acid: Physico-Chemical Aspects of Manufacture" in Inorganic Sulphur Chemistry, G. Nickless, Ed. (Elsevier, New York, 1968) pp 535-561; Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 795-806. Toxicity data: H. F. Smyth et al., Am. Ind. Hyg. Assoc. J. 30, 470 (1969). Review of toxicology and human exposure: Toxicological Profile for Sulfur Trioxide and Sulfuric Acid (PB99-122038, 1998) 224 pp.
Properties: Clear, colorless, odorless, oily liquid. Very corrosive! Has a very great affinity for water, abstracting it from the air and also from many organic substances; hence it chars sugar, wood, etc. d ~1.84. bp ~290°; dec 340° into sulfur trioxide and water. mp 10° (anhydrous acid). 98% H2SO4 freezes at +3°; 93% at -32°; 78% at -38°; 74% at -44°; 65% at -64°. Misc with water and alcohol with the generation of much heat and with contraction in vol. When diluting, the acid should be added to the diluent. Keep tightly closed. Handle with caution. Avoid contact with skin. LD50 orally in rats: 2.14 g/kg (Smyth).
Melting point: mp 10° (anhydrous acid)
Boiling point: bp ~290°
Density: d ~1.84
Toxicity data: LD50 orally in rats: 2.14 g/kg (Smyth)
Derivative Type: Sulfuric acid, fuming
CAS Registry Number: 8014-95-7
Properties: H2SO4 with free SO3, designated in commerce as oleum. Available grades contain up to about 80% free SO3. Colorless or slightly colored, viscous liquid, emitting choking fumes of sulfur trioxide. Extremely corrosive. Handle with great care. Avoid contact with skin. Keep tightly closed in glass-stoppered bottles.
CAUTION: Potential symptoms of overexposure are eye, skin, nose and throat irritation; pulmonary edema, bronchitis; emphysema; conjunctivitis; stomatis; dental erosion; tracheobronchitis; skin and eye burns; dermatitis. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 290. See also Clinical Toxicology of Commercial Products, R. E. Gosselin et al., Eds. (Williams & Wilkins, Baltimore, 5th ed., 1984) section III, pp 8-12. Occupational exposure to strong inorganic acid mists containing sulfuric acid is listed as a known human carcinogen: Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-234.
Use: In manuf of fertilizers, explosives, dyestuffs, other acids, parchment paper, glue, purification of petroleum, pickling of metal.
Therap-Cat: Dil acid formerly in treatment of gastric hypoacidity. Concd acid formerly as a topical caustic. |