CompoundsAll compoundsSodium hydroxide
NaOH
Compound · Base

Sodium hydroxide

氢氧化钠 (烧碱)

Sodium hydroxide (氢氧化钠 (烧碱)), formula NaOH, is a base with a molar mass of 40 g/mol (CAS 1310-73-2). White solid, strongly deliquescent; very soluble in water; dissolving is strongly exothermic.

Key facts

Molar mass40 g/mol
CategoryBase
State at 25°CSolid
CAS1310-73-2

Structure

Na⁺ [O–H]⁻

Ionic compound of Na⁺ and OH⁻

Physical properties

AppearanceWhite solid, strongly deliquescent
Melting point318 °C
Boiling point1388 °C
Density2.13 g/cm³
SolubilityVery soluble in water; dissolving is strongly exothermic

Key reactions

NaOH + HCl → NaCl + H₂O
Neutralisation with acid
2NaOH + CO₂ → Na₂CO₃ + H₂O
Absorbs CO₂ and other acidic gases
CuSO₄ + 2NaOH → Cu(OH)₂↓ + Na₂SO₄
Forms blue Cu(OH)₂ precipitate with copper salts

Main uses

Hazard

HighStrong caustic base; severely burns skin and eyes

Constituent elements

Data sources

CAS1310-73-2PubChemNIST WebBookCAS Common ChemistryWikipediaTextbook (general chemistry)

Molar mass is computed from IUPAC (CIAAW) standard atomic weights; formula, properties and reactions can be verified on PubChem, NIST and Wikipedia. The CAS number is the substance's unique registry identifier. Educational reference only.