8675. Sodium Silicate

Properties

The compositions of the commonly available sodium silicates in dry form are: Na₂SiO₃, Na₆Si₂O₇, and Na₂Si₃O₇, with variable amounts of water, the first-named containing approx 5H₂O. They are in the form of colorless to white or grayish-white, crystal-like pieces or lumps. These silicates are very slightly sol or almost insol in cold water. They are best brought into soln by heating with water under pressure. They are less readily sol in large amounts of water than in small amounts of water, and the anhydr dissolve with more difficulty than the hydrated silicates; also, the silicates containing more sodium dissolve more readily. The aq solns are strongly alkaline. The dry sodium silicates are used relatively little. See also Sodium Metasilicate.

Caution

Irritating and caustic to skin, mucous membranes. If swallowed causes vomiting and diarrhea.