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Sodium Hydroxide

Sodium hydroxide
Unit cell, spacefill model of sodium hydroxide
Sample of sodium hydroxide as pellets in a watchglass
Names
Preferred IUPAC name
Sodium hydroxide
Systematic IUPAC name
Sodium oxidanide
Other names
Caustic soda

Lye
Ascarite
White caustic

Sodium hydrate
Identifiers
1310-73-2 YesY
3D model (Jmol) Interactive image
ChEBI CHEBI:32145 YesY
ChemSpider 14114 YesY
ECHA InfoCard 100.013.805
EC Number 215-185-5
E number E524 (acidity regulators, ...)
68430
KEGG D01169 YesY
MeSH Sodium+Hydroxide
PubChem 14798
RTECS number WB4900000
UNII 55X04QC32I YesY
UN number 1823
Properties
NaOH
Molar mass 39.9971 g mol−1
Appearance White, waxy, opaque crystals
Odor odorless
Density 2.13 g/cm3
Melting point 318 °C (604 °F; 591 K)
Boiling point 1,388 °C (2,530 °F; 1,661 K)
418 g/L (0 °C)
1110 g/L (20 °C)
3370 g/L (100 °C)
Solubility soluble in glycerol
negligible in ammonia
insoluble in ether
Solubility in methanol 238 g/L
Solubility in ethanol <<139 g/L
Vapor pressure <2.4 kPa (at 20 °C)
Basicity (pKb) −0.93(NaOH(aq) = Na+ + OH)
−16.0·10−6 cm3/mol
1.3576
Thermochemistry
59.66 J/mol K
64 J·mol−1·K−1
−427 kJ·mol−1
-380.7 kJ/mol
Hazards
Safety data sheet External MSDS
GHS pictograms The corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H314
P280, P305+351+338, P310
Corrosive C
R-phrases R35
S-phrases (S1/2), S26, S37/39, S45
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazard ALK: Alkaline.NFPA 704 four-colored diamond
Lethal dose or concentration (LD, LC):
LD50 (median dose)
40 mg/kg (mouse, intraperitoneal)
500 mg/kg (rabbit, oral)
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 2 mg/m3
REL (Recommended)
C 2 mg/m3
IDLH (Immediate danger)
10 mg/m3
Related compounds
Other anions
Sodium hydrosulfide
Other cations
Caesium hydroxide

Lithium hydroxide
Potassium hydroxide
Rubidium hydroxide

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

Lye
Ascarite
White caustic

Lithium hydroxide
Potassium hydroxide
Rubidium hydroxide

Sodium hydroxide (NaOH), also known as lye and caustic soda, is an inorganic compound. It is a white solid and highly caustic metallic base and alkali of sodium which is available in pellets, flakes, granules, and as prepared solutions at different concentrations. Sodium hydroxide forms an approximately 50% (by mass) saturated solution with water.

Sodium hydroxide is soluble in water, ethanol, and methanol. This alkali is deliquescent and readily absorbs moisture and carbon dioxide in air.

Sodium hydroxide is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Worldwide production in 2004 was approximately 60 million tonnes, while demand was 51 million tonnes.

Pure sodium hydroxide is a whitish solid, sold in pellets, flakes, and granular form, as well as in solution. It is highly soluble in water, with a lower solubility in ethanol and methanol, but is insoluble in ether and other non-polar solvents.


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Wikipedia

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