Sodium tetraborate

Borax
Names


IUPAC name Sodium tetraborate decahydrate
Identifiers
CAS Number	1303-96-4 (decahydrate)^Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:86222^N
ChEMBL	ChEMBL1076681^N
ChemSpider	17339255^Y
ECHA InfoCard	100.014.129
EC Number	215-540-4
E number	E285 (preservatives)
UNII	91MBZ8H3QO^Y
InChI InChI=1S/B4O7.2Na.10H2O/c5-1-7-3-9-2(6)10-4(8-1)11-3;;;;;;;;;;;;/h;;;101H2/q-2;2+1;;;;;;;;;;^Y Key: CDMADVZSLOHIFP-UHFFFAOYSA-N^Y InChI=1/B4O7.2Na.10H2O/c5-1-7-3-9-2(6)10-4(8-1)11-3;;;;;;;;;;;;/h;;;101H2/q-2;2+1;;;;;;;;;; Key: CDMADVZSLOHIFP-UHFFFAOYAP
SMILES [Na+].[Na+].[O-]B1OB2OB([O-])OB(O1)O2.O.O.O.O.O.O.O.O.O.O
Properties
Chemical formula	Na₂B₄O₇·10H₂O or Na₂[B₄O₅(OH)₄]·8H₂O
Molar mass	381.38 (decahydrate) 201.22 (anhydrate)
Appearance	white solid
Density	1.73 g/cm³ (solid)
Melting point	743 °C (1,369 °F; 1,016 K) anhydrate
Boiling point	1,575 °C (2,867 °F; 1,848 K)
Magnetic susceptibility (χ)	−85.0·10⁻⁶ cm³/mol
Structure
Crystal structure	Monoclinic Prismatic
Space group	C2/c
Point group	2/m
Pharmacology
ATC code	S01AX07 (WHO)
Hazards
NFPA 704	0 1 0
US health exposure limits (NIOSH):
PEL (Permissible)	none
REL (Recommended)	TWA 1 mg/m³ (anhydrate and pentahydrate) TWA 5 mg/m³ (decahydrate)
IDLH (Immediate danger)	N.D.
Related compounds
Other anions	Sodium aluminate; sodium gallate
Other cations	Potassium tetraborate
Related compounds	Boric acid, sodium perborate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N (what is ^YN ?)
Infobox references

Borax, also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important boron compound, a mineral, and a salt of boric acid. Powdered borax is white, consisting of soft colorless crystals that dissolve easily in water.

Borax has a wide variety of uses. It is a component of many detergents, cosmetics, and enamel glazes. It is also used to make buffer solutions in biochemistry, as a fire retardant, as an anti-fungal compound, in the manufacture of fiberglass, as a flux in metallurgy, neutron-capture shields for radioactive sources, a texturing agent in cooking, as a precursor for other boron compounds, and along with its inverse, boric acid, is useful as an insecticide.

In artisanal gold mining, the borax method is sometimes used as a substitute for toxic mercury in the gold extraction process. Borax was reportedly used by gold miners in parts of the Philippines in the 1900s.

The term borax is used for a number of closely related minerals or chemical compounds that differ in their crystal water content, but usually refers to the . Commercially sold borax is partially dehydrated.

Borax was first discovered in dry lake beds in Tibet and was imported via the Silk Road to the Arabian Peninsula in the 8th Century AD. Borax first came into common use in the late 19th century when Francis Marion Smith's Pacific Coast Borax Company began to market and popularize a large variety of applications under the 20 Mule Team Borax trademark, named for the method by which borax was originally hauled out of the California and Nevada deserts in large enough quantities to make it cheap and commonly available.

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Wikipedia