Title: Sulfamic Acid
CAS Registry Number: 5329-14-6
Additional Names: Amidosulfonic acid
Molecular Formula: H3NO3S
Molecular Weight: 97.09
Percent Composition: H 3.11%, N 14.43%, O 49.44%, S 33.03%
Line Formula: H2NSO3H
Literature References: Obtained from chlorosulfonic acid and ammonia, or by heating urea with H2SO4. Purification: Sisler et al., Inorg. Synth. 2, 178 (1946). Toxicity data: Ambrose, J. Ind. Hyg. Toxicol. 25, 26 (1943). Reviews: Audrieth et al., Chem. Rev. 26, 49 (1940); Burton, Nickless, "Amido- and Imido-Sulfonic Acids" in Inorganic Sulphur Chemistry, G. Nickless, Ed. (Elsevier, New York, 1968) pp 607-627, 661-667; E. B. Bell in Kirk-Othmer Encyclopedia of Chemical Technology vol. 21 (Wiley-Interscience, New York, 3rd ed., 1983) pp 949-960. Brief review of synthetic applications: B. Wang, Synlett 2005, 1342-1343.
Properties: Orthorhombic crystals. d 2.15. mp ~205° (dec). Stable when dry but in soln slowly hydrolyzes forming ammonium bisulfate. Sol in 6.5 parts water at 0°, in about 2 parts water at 80°. Sulfuric acid decreases soly in water. Sparingly sol in alcohol, methanol; slightly sol in acetone. Insol in ether. Freely sol in nitrogenous bases, e.g., liq ammonia, also in nitrogen contg organic solvents, e.g., pyridine, formamide, dimethylformamide. Immiscible with toluene, THF. A strong acid; pH of a 1% soln at 25° 1.18. Can be titrated with bases by means of indicators showing color change between pH 4.5 to 9. MLD orally in rats: 1.6 g/kg (Ambrose).
Melting point: mp ~205° (dec)
Density: d 2.15
Toxicity data: MLD orally in rats: 1.6 g/kg (Ambrose)
CAUTION: Moderately irritating to skin, mucous membranes.
Use: As standard in alkalimetry; in acid cleaning; in nitrite removal; in chlorine stabilization for use in swimming pools, cooling towers, paper mills. Solid-acid catalyst in organic synthesis. The acid or its ammonium salt has been recommended for flameproofing fabrics and wood. Metal salts are used in electroplating. Ammonium sulfamate, q.v., is also widely used as a weed killer. |