Key Facts

Other Names:

Sodium metasilicate; soluble glass; water glass

Formula:

Varies; often represented as Na₂SiO₃; see Overview

Elements:

Sodium, silicon, oxygen

Compound Type:

Salt (inorganic)

State:

Ranges from solid to liquid

Molecular Weight:

Varies; sodium metasilicate: 122.06 g/mol

Melting Point:

Varies; sodium metasilicate: 1089°C (1992°F)

Boiling Point:

Not applicable

Solubility:

Soluble in cold water; reacts chemically with hot water

Overview

Sodium silicate (SO-dee-um SILL-uh-kate) is a generic term that refers to a series of compounds with varying proportions of sodium oxide (Na₂O) and silicon dioxide (SiO₂). The term is sometimes used synonymously with a specific form of the compound called sodium metasilicate, with the chemical formula Na₂SiO₃. Other forms typically range from Na₂O•_3.75SiO₂ to 2Na₂O•SiO₂ with one or more molecules of water of hydration. Sodium silicate is a white amorphous (without crystalline structure) solid with the physical properties...