Characteristic

 

Sodium metaborate is a colorless solid chemical compound of sodium, boron, and oxygen with formula NaBO₂. The formula can be written also as Na₂O·B₂O₃ to highlight the relation to the main oxides of sodium and boron.

Chemical formula:NaBO₂•4H₂O

Molar mass: 137.86 g/mol

Appearance: white crystals

Odor: odorless

Density: 2.464 g/mL (anhydrous)

Melting point: 966 °C (1,771 °F; 1,239 K)

Boiling point: 1,434 °C (2,613 °F; 1,707 K)

Solubility in water:16.4 g/100 mL (0 °C);28.2 g/100 mL (25 °C);125.2 g/100 mL (100 °C)

Solubility: insoluble in ether, ethanol

Crystal structure:trigonal

 

Application

 

Sodium metaborate is used in the manufacturing of borosilicate glasses. It is also a component of herbicides and antifreeze products.