Sodium hydroxide

Sodium hydroxide, kent as caustic soda an aw,^[1][2] or lye, is an inorganic compoond wi the chemical formula NaOH (written as NaHO an aw). It is a white solit, an is a heichly caustic metallic base an alkali saut. It is available in pellets, flakes, granules, an as prepared solutions at a nummer o different concentrations.^[4] Sodium hydroxide furms an approximately 50% (bi wecht) saturatit solution wi watter.^[5]

Sodium hydroxide

Names
Preferred IUPAC name Sodium hydroxide[3]
Seestematic IUPAC name Sodium oxidanide
Ither names Caustic soda Lye [1][2] Ascarite White caustic Sodium hydrate[3]
Identifiers
CAS Nummer	1310-73-2 Y
3D model (JSmol)	Interactive eemage
ChEBI	CHEBI:32145 Y
ChemSpider	14114 Y
EC Nummer	215-185-5
Gmelin Reference	68430
KEGG	D01169 Y
MeSH	Sodium+Hydroxide
PubChem CID	14798
RTECS nummer	WB4900000
UNII	55X04QC32I Y
UN nummer	1823
InChI InChI=1S/Na.H2O/h;1H2/q+1;/p-1 Y Key: HEMHJVSKTPXQMS-UHFFFAOYSA-M Y InChI=1/Na.H2O/h;1H2/q+1;/p-1 Key: HEMHJVSKTPXQMS-REWHXWOFAM
SMILES O[Na]
Properties
Chemical formula	NaOH
Molar mass	39.9971 g mol−1
Appearance	White, waxy, opaque crystals
Odour	odorless
Density	2.13 g/cm3
Meltin pynt	318 °C (604 °F; 591 K)
Bylin pynt	1,388 °C (2,530 °F; 1,661 K)
Solubility in watter	111 g/100 mL (at 20 °C)
Solubility in methanol	23.8 g/100 mL
Solubility in ethanol	<<13.9 g/100 mL
Vapour pressur	<2.4 kPa (at 20 °C)
Acidity (pKa)	13
Refractive index (nD)	1.3576
Hazards
GHS pictograms
NFPA 704	0 3 1 ALK
Relatit compoonds
Ither anions	Sodium hydrosulfide
Ither cations	Caesium hydroxide Lithium hydroxide Potassium hydroxide Rubidium hydroxide
Except whaur itherwise notit, data are gien for materials in thair staundart state (at 25 °C [77 °F], 100 kPa).
Y verify (whit is YN ?)
Infobox references

Sodium hydroxide is soluble in watter, ethanol an methanol. This alkali is deliquescent an readily absorbs moistur an carbon dioxide in air.

Sodium hydroxide is uised in mony industries, maistly as a strang chemical base in the manufacture o pulp an paper, textiles, drinkin watter, saips an detergents an as a drain cleaner. Warldwide production in 2004 wis approximately 60 million tonnes, while demand wis 51 million tonnes.^[6]