Nomenclature
CAS number: 7757-79-1
Nitric acid potassium salt (1:1).
KNO
3; mol wt 101.10.
K 38.67%, N 13.85%, O 47.48%.
Description and references
Occurs in nature as the mineral saltpeter or niter. Polymorphism: F. C. Kracek, J. Phys. Chem. 34, 225 (1930). Prepn from
potassium chloride: D. L. Reed, K. G. Clark, Ind. Eng. Chem. 29, 333 (1937); by molten
salt technique: R. W. Pfeiffer et al., J. Agric. Food Chem. 15, 949
(1967); by solvent separation of strong acids: A. Eyal et al., Ind. Eng. Chem. Process Des. Dev. 24, 387 (1985). Viscosity: R. E. Wellman et al., J. Chem. Eng. Data 11, 156 (1966). Heat capacity: E. W. Dewing, ibid. 20, 221 (1975). Clinical evaluations in tooth hypersensitivity:
M. Hodosh, J. Am. Dent. Assoc. 88, 831 (1974); T. Nagata et al., J. Clin. Periodontol. 21, 217
(1994); S. C. Frechoso et al., ibid. 30, (2003).
Properties
Colorless transparent prisms, white granular or
cryst powder; cooling, saline, pungent taste. d 2.11; mp 333°; dec at 400° with evolution of O2. Oxidizer. One gram dissolves in 2.8 ml water,
0.5 ml boiling water, 620 ml alc. Sol in glycerol; insol in abs alc.
Dissolves in water with a lowering of the temp. pH ≈7. LD50 orally in rabbits:
1.166 g anion/kg, Dollahite, Rowe, Southwest. Vet. 27, 246 (1974).Caution
Ingestion of large quantities may
cause violent gastroenteritis. Prolonged exposure to small amts may
produce anemia, methemoglobinemia, nephritis.Use
In fireworks, fluxes, pickling meats; production
of nitric acid; manuf glass, matches, gunpowder; freezing mixtures.
Agricultural fertilizer. Preservative in foods. In dentrifices
to reduce tooth hypersensitivity.