Nomenclature
CAS number: 497-19-8
Carbonic acid sodium salt (1:2).
CNa
2O
3; mol wt 105.99.
C 11.33%, Na 43.38%, O 45.29%.
Na
2CO
3.
Description and references
Occurs in nature as the hydrate, thermonatrite, and the decahydrate, natron or natrite. Produced by the ammonia-soda or Solvay process, or from
lake brines or sea water by electrolytic processes: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York,
4th ed., 1975) pp 706-715. Toxicity: C. Norde et al., Compt. Rend. 257, 791 (1963). Reviews: Bailey in Mellor's vol II, suppl II, The Alkali
Metals (part 1), 1058-1205 (1961).
Derivative
Anhydrous.
Properties
The technical grade (about 99% pure) is known
as soda ash. Odorless, hygroscopic powder; alkaline taste; d 2.53. mp 851° but begins to lose CO2 even at 400°. On exposure to air it will gradually absorb
one mol water, about 15%. Sol in glycerol; in 3.5 parts water at
room temp, 2.2 parts water at 35°. Insol in alcohol. Dec by acids
with effervescence. Combines with water with evolution of heat.
Its aq soln is strongly alkaline. pH 11.6. Keep well closed. LD50 (30
day) i.p. in mice: 116.6 mg/kg (Norde).Derivative
Monohydrate.
Nomenclature
CAS number: 5968-11-6
CNa
2O
3.H
2O; mol wt 124.00.
C 9.69%, Na 37.08%, O 51.61%, H 1.63%.
Properties
Odorless, small crystals or cryst powder; alkaline
taste. Stable at ordinary temps and atmospheric conditions; dries
out somewhat in warm, dry air or above 50°; becomes anhydr at 100°.
d 2.25; also reported as 1.55. Sol in 3 parts water, 1.8 parts boiling
water, 7 parts glycerol. Insol in alcohol.Derivative
Decahydrate.
Nomenclature
CAS number: 6132-02-1
Nevite; Soda.
CNa
2O
3.10H
2O; mol wt 286.14.
C 4.20%, Na 16.07%, O 72.69%, H 7.05%.
Properties
The technical product is known as sal soda or washing soda. Transparent crystals; readily effloresces on exposure
to air. d 1.46. mp 30°. Sol in 2 parts
cold, 0.25 part boiling water, in glycerol. Insol in alcohol. The
aq soln is strongly alkaline to litmus. Keep
well closed and in a cool place.Caution
Potential symptoms of overexposure
to dusts or vapors of sodium carbonate are irritation of mucous membranes
with subsequent coughing and shortness of breath. Chronic overexposure
may lead to perforation of the nasal septum. Direct contact may cause
skin irritation and redness, with concentrated solutions causing erythema.
Chronic skin exposures may cause dermatitis and ulceration. See Patty's Industrial Hygiene and
Toxicology vol. 2A, G. D. Clayton, F. E. Clayton,
Eds. (Wiley-Interscience, New York, 4th ed., 1993) pp 769-771.Use
In manuf of Na salts, glass, soap; for washing wool;
textiles, etc.; in bleaching linen, cotton; general cleanser; in water-softening;
in photography; as reagent in analytical chemistry for pH adjustment;
buffer; standard for acid-base titrimetry. Pharmaceutic aid (alkalizer).
Therapeutic Category (Veterinary)
Has been used as an emetic. In solution
to cleanse skin, in eczema, to soften scabs of ringworm.