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Acids and bases

Sodium hydroxide vs potassium hydroxide

Sodium hydroxide (HNaO, CAS 1310-73-2) and potassium hydroxide (HKO, CAS 1310-58-3) are both listed under hydroxides and bases.

Sodium hydroxide has a molar mass of 40.00 g/mol, potassium hydroxide 56.11 g/mol.

Measured boiling points are 1,388 °C for sodium hydroxide and 1,327 °C for potassium hydroxide.

Both carry the GHS signal word Danger.

On CompoundList, 1,399 suppliers list sodium hydroxide and 706 suppliers list potassium hydroxide.

Data last updated 7 October 2026

Sodium hydroxide and potassium hydroxide compared side by side
Sodium hydroxide chemical structure, HNaO, CAS 1310-73-2
Sodium hydroxide
Potassium hydroxide chemical structure, HKO, CAS 1310-58-3
Potassium hydroxide
Identity
Name in our databaseSodium hydroxidePotassium hydroxide
CAS number1310-73-21310-58-3
Molecular formulaHNaOHKO
Molar mass40.00 g/mol56.11 g/mol
IUPAC namesodium hydroxidepotassium hydroxide
EC number215-185-5215-181-3
Physical properties
AppearanceWhite, orthogonal crystalsWhite or colorless, orthorhombic, deliquescent pieces, lumps, or sticks having crystalline fracture
Melting point323 °CCa. 360
Boiling point1,388 °C1,327 °C
Density2.13 g/cm³ 25 °C2.044 g/cm³
Solubility1 g dissolves in 0.9 mL water, 0.3 mL boiling waterSolubility in water, 121 g/100 g water at 25 °C
LogP (octanol/water)Computed from the structure-3.17-3.17
Safety (GHS)
Signal wordDangerDanger
Pictograms
GHS05: Corrosive
GHS05: Corrosive
GHS07: Harmful or irritant
Hazard statements
  • H314 Causes severe skin burns and eye damage.
  • H302 Harmful if swallowed.
  • H314 Causes severe skin burns and eye damage.
UN numberUN 1823UN 1813
Uses and classification
Uses and functions
  • PH adjusters
  • Acids and alkalis
  • Buffering
  • Denaturant
  • Binder
  • Biocide
  • Acidulants and acidity regulators
  • PH adjusters
  • High-purity wet chemicals
  • Acids and alkalis
  • Buffering
  • Anti-caking agent
CategoryInorganic chemicals › Hydroxides and basesInorganic chemicals › Hydroxides and bases
HS code281511Sodium hydroxide (caustic soda), solid281520Potassium hydroxide (caustic potash)
Market on CompoundList
Suppliers1,399 suppliers706 suppliers
Supplier countries88 countries, most in India, United States, China62 countries, most in India, United States, China
Price rangeOnly prices set by suppliers who manage their own profilePrice on requestPrice on request

Measured and computed values as shown on each chemical page, plus live listings on CompoundList. Details may have changed, please confirm them with the supplier. Safety data is a summary, not an SDS.

Sodium hydroxide
Potassium hydroxide

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