*** Welcome to piglix ***

Borax

Borax
Borax crystals
Ball-and-stick model of the unit cell of borax decahydrate
Names
IUPAC name
Sodium tetraborate decahydrate
Identifiers
1303-96-4 (decahydrate) YesY
3D model (Jmol) Interactive image
ChEBI CHEBI:86222 N
ChEMBL ChEMBL1076681 N
ChemSpider 17339255 YesY
ECHA InfoCard 100.014.129
EC Number 215-540-4
E number E285 (preservatives)
UNII 91MBZ8H3QO YesY
Properties
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)
−85.0·10−6 cm3/mol
Structure
Monoclinic Prismatic
C2/c
2/m
Pharmacology
S01AX07 (WHO)
Hazards
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
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 YesYN ?)
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.


...
Wikipedia

...