Nomenclature
CAS number: 6834-92-0
Na
2O
3Si; mol wt 122.06.
Na 37.67%, O 39.32%, Si 23.01%.
Na
2SiO
3.
Description and references
Usually prepared from sand (SiO2) and soda ash (Na2CO3) by fusion: Schwarz, Z. Anorg. Allg. Chem. 126, 62
(1923); Faith, Keyes & Clark's Industrial
Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience,
New York, 4th ed., 1975) pp 755-761. Review: Gmelins, Sodium (8th ed. supplement) 21, pp 1474-1478 (1967).
Properties
Usually obtained as a glass; also orthorhombic
crystals. d 2.614.
mp 1089°. nD25 (glass) 1.520. Specific heat (20°): 0.217.
Heat of formation: 371.2 kcal/mol. Heat of soln (cryst) 7.45 kcal/mol.
Heat of fusion: 10.3 kcal/mol. Sol in cold water, hydrolyzed by
hot water. Insol in alcohol, acids, salt solns.Derivative
Nonahydrate.
Properties
Efflorescent, orthorhombic bipyramidal platelets, mp 48° in water of crystn.
Heat of hydration: 24.15 kcal/mol.