Potassium hydroxide

Potassium hydroxide
Names
	IUPAC name Potassium hydroxide
	Other names Caustic potash; Lye; Potash lye; Potassia; Potassium hydrate; KOH;
Identifiers
CAS Number	1310-58-3 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:32035 ;
ChemSpider	14113 ;
ECHA InfoCard	100.013.802
EC Number	215-181-3;
E number	E525 (acidity regulators, ...)
PubChem CID	14797;
RTECS number	TT2100000;
UNII	WZH3C48M4T ;
UN number	1813
CompTox Dashboard (EPA)	DTXSID5029633 ;
	InChI InChI=1S/K.H2O/h;1H2/q+1;/p-1 Key: KWYUFKZDYYNOTN-UHFFFAOYSA-M ; InChI=1/K.H2O/h;1H2/q+1;/p-1 Key: KWYUFKZDYYNOTN-REWHXWOFAT;
	SMILES [K+].[OH-];
Properties
Chemical formula	KOH
Molar mass	56.105 g·mol−1
Appearance	white solid, deliquescent
Odor	odorless
Density	2.044 g/cm3 (20 °C); 2.12 g/cm3 (25 °C)
Melting point	410 °C (770 °F; 683 K)
Boiling point	1,327 °C (2,421 °F; 1,600 K)
Solubility in water	85 g/100 mL (-23.2 °C); 97 g/100 mL (0 °C); 121 g/100 mL (25 °C); 138.3 g/100 mL (50 °C); 162.9 g/100 mL (100 °C)
Solubility	soluble in alcohol, glycerol ; insoluble in ether, liquid ammonia
Solubility in methanol	55 g/100 g (28 °C)
Solubility in isopropanol	~14 g / 100 g (28 °C)
Acidity (pKa)	14.7
Magnetic susceptibility (χ)	−22.0·10−6 cm3/mol
Refractive index (nD)	1.409 (20 °C)
Thermochemistry
Heat capacity (C)	65.87 J/mol·K
Std molar; entropy (S⦵298)	79.32 J/mol·K
Std enthalpy of; formation (ΔfH⦵298)	-425.8 kJ/mol
Gibbs free energy (ΔfG⦵)	-380.2 kJ/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H290, H302, H314
Precautionary statements	P280, P305+P351+P338, P310
NFPA 704 (fire diamond)	3 0 1 ALK
Flash point	nonflammable
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	273 mg/kg (oral, rat)
	NIOSH (US health exposure limits):
PEL (Permissible)	none
REL (Recommended)	C 2 mg/m3
IDLH (Immediate danger)	N.D.
Safety data sheet (SDS)	ICSC 0357
Related compounds
Other anions	Potassium hydrosulfide; Potassium amide
Other cations	Lithium hydroxide; Sodium hydroxide; Rubidium hydroxide; Caesium hydroxide
Related compounds	Potassium oxide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash.

Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utilize its caustic nature and its reactivity toward acids. An estimated 700,000 to 800,000 tonnes were produced in 2005. KOH is noteworthy as the precursor to most soft and liquid soaps, as well as numerous potassium-containing chemicals. It is a white solid that is dangerously corrosive.^[11]

^ ^a ^b Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. p. 4-80. ISBN 0-8493-0486-5.
^ ^a ^b ^c ^d ^e ^f "potassium hydroxide". chemister.ru. Archived from the original on 18 May 2014. Retrieved 8 May 2018.
^ Otto, H.W; Seward, R.P. (1964). "Phase equilibria in the potassium hydroxide-sodium hydroxide system". J. Chem. Eng. Data. 9: 507. doi:10.1021/je60023a009.
^ Seward, R.P; Martin, K.E. (1949). "The melting point of potassium hydroxide". J. Am. Chem. Soc. 71: 3564. doi:10.1021/ja01178a530.
^ Seidell, Atherton; Linke, William F. (1952). Solubilities of Inorganic and Organic Compounds. Van Nostrand. Retrieved 2014-05-29.
^ Popov, K.; et al. (2002). "⁷Li, ²³Na, ³⁹K and ¹³³Cs NMR comparative equilibrium study of alkali metal cation hydroxide complexes in aqueous solutions. First numerical value for CsOH formation". Inorganic Chemistry Communications. 3 (5): 223–225. doi:10.1016/S1387-7003(02)00335-0. ISSN 1387-7003. Retrieved October 20, 2018.
^ ^a ^b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A22. ISBN 978-0-618-94690-7.
^ ^a ^b ^c Sigma-Aldrich Co., Potassium hydroxide. Retrieved on 2014-05-18.
^ ^a ^b ^c NIOSH Pocket Guide to Chemical Hazards. "#0523". National Institute for Occupational Safety and Health (NIOSH).
^ Chambers, Michael. "ChemIDplus - 1310-58-3 - KWYUFKZDYYNOTN-UHFFFAOYSA-M - Potassium hydroxide [JAN:NF] - Similar structures search, synonyms, formulas, resource links, and other chemical information". chem.sis.nlm.nih.gov. Archived from the original on 12 August 2014. Retrieved 8 May 2018.
^ Schultz, Heinz; Bauer, Günter; Schachl, Erich; Hagedorn, Fritz; Schmittinger, Peter (2005). "Potassium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim, Germany: Wiley-VCH. doi:10.1002/14356007.a22_039. ISBN 978-3-527-30673-2.

[crc-1] Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. p. 4-80. ISBN 0-8493-0486-5.

[chemister-2] ^ ^a ^b ^c ^d ^e ^f "potassium hydroxide". chemister.ru. Archived from the original on 18 May 2014. Retrieved 8 May 2018.

[3] Otto, H.W; Seward, R.P. (1964). "Phase equilibria in the potassium hydroxide-sodium hydroxide system". J. Chem. Eng. Data. 9: 507. doi:10.1021/je60023a009.

[4] Seward, R.P; Martin, K.E. (1949). "The melting point of potassium hydroxide". J. Am. Chem. Soc. 71: 3564. doi:10.1021/ja01178a530.

[sioc-5] Seidell, Atherton; Linke, William F. (1952). Solubilities of Inorganic and Organic Compounds. Van Nostrand. Retrieved 2014-05-29.

[6] Popov, K.; et al. (2002). "⁷Li, ²³Na, ³⁹K and ¹³³Cs NMR comparative equilibrium study of alkali metal cation hydroxide complexes in aqueous solutions. First numerical value for CsOH formation". Inorganic Chemistry Communications. 3 (5): 223–225. doi:10.1016/S1387-7003(02)00335-0. ISSN 1387-7003. Retrieved October 20, 2018.

[b1-7] Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A22. ISBN 978-0-618-94690-7.

[sigma-8] Sigma-Aldrich Co., Potassium hydroxide. Retrieved on 2014-05-18.

[PGCH-9] NIOSH Pocket Guide to Chemical Hazards. "#0523". National Institute for Occupational Safety and Health (NIOSH).

[10] Chambers, Michael. "ChemIDplus - 1310-58-3 - KWYUFKZDYYNOTN-UHFFFAOYSA-M - Potassium hydroxide [JAN:NF] - Similar structures search, synonyms, formulas, resource links, and other chemical information". chem.sis.nlm.nih.gov. Archived from the original on 12 August 2014. Retrieved 8 May 2018.

[Ullmann-11] Schultz, Heinz; Bauer, Günter; Schachl, Erich; Hagedorn, Fritz; Schmittinger, Peter (2005). "Potassium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim, Germany: Wiley-VCH. doi:10.1002/14356007.a22_039. ISBN 978-3-527-30673-2.

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Names


IUPAC name Potassium hydroxide
Other names Caustic potash Lye Potash lye Potassia Potassium hydrate KOH
Identifiers
CAS Number	1310-58-3^Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:32035^Y
ChemSpider	14113^Y
ECHA InfoCard	100.013.802
EC Number	215-181-3
E number	E525 (acidity regulators, ...)
PubChem CID	14797
RTECS number	TT2100000
UNII	WZH3C48M4T^Y
UN number	1813
CompTox Dashboard (EPA)	DTXSID5029633
InChI InChI=1S/K.H2O/h;1H2/q+1;/p-1^Y Key: KWYUFKZDYYNOTN-UHFFFAOYSA-M^Y InChI=1/K.H2O/h;1H2/q+1;/p-1 Key: KWYUFKZDYYNOTN-REWHXWOFAT
SMILES [K+].[OH-]
Properties
Chemical formula	KOH
Molar mass	56.105 g·mol⁻¹
Appearance	white solid, deliquescent
Odor	odorless
Density	2.044 g/cm³ (20 °C)^[1] 2.12 g/cm³ (25 °C)^[2]
Melting point	410^[3]^[4] °C (770 °F; 683 K)
Boiling point	1,327 °C (2,421 °F; 1,600 K)
Solubility in water	85 g/100 mL (-23.2 °C) 97 g/100 mL (0 °C) 121 g/100 mL (25 °C) 138.3 g/100 mL (50 °C) 162.9 g/100 mL (100 °C)^[1]^[5]
Solubility	soluble in alcohol, glycerol insoluble in ether, liquid ammonia
Solubility in methanol	55 g/100 g (28 °C)^[2]
Solubility in isopropanol	~14 g / 100 g (28 °C)
Acidity (pK_a)	14.7^[6]
Magnetic susceptibility (χ)	−22.0·10⁻⁶ cm³/mol
Refractive index (n_D)	1.409 (20 °C)
Thermochemistry
Heat capacity (C)	65.87 J/mol·K^[2]
Std molar entropy (S^⦵₂₉₈)	79.32 J/mol·K^[2]^[7]
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	-425.8 kJ/mol^[2]^[7]
Gibbs free energy (Δ_fG^⦵)	-380.2 kJ/mol^[2]
Hazards
GHS labelling:
Pictograms	^[8]
Signal word	Danger
Hazard statements	H290, H302, H314^[8]
Precautionary statements	P280, P305+P351+P338, P310^[8]
NFPA 704 (fire diamond)	3 0 1 ALK
Flash point	nonflammable
Lethal dose or concentration (LD, LC):
LD₅₀ (median dose)	273 mg/kg (oral, rat)^[10]
NIOSH (US health exposure limits):
PEL (Permissible)	none^[9]
REL (Recommended)	C 2 mg/m³^[9]
IDLH (Immediate danger)	N.D.^[9]
Safety data sheet (SDS)	ICSC 0357
Related compounds
Other anions	Potassium hydrosulfide Potassium amide
Other cations	Lithium hydroxide Sodium hydroxide Rubidium hydroxide Caesium hydroxide
Related compounds	Potassium oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references