Potassium chloride

Athanor · official

ClK · 74.55 g/mol

Also called sylvite, KCl, E508

Inorganic

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Drawn from its SMILES with RDKit

Names and identifiers

IUPAC name: potassium chloride
Synonyms: sylvite, KCl, E508
+ 38 more
Klotrix, Sylvite, Enseal, Slow-K, Muriate of potash, Neobakasal, Klor-Con, Acronitol, Chlorvescent, Potavescent, Kalitabs, Kaochlor, Pfiklor, Rekawan, Kloren, Chloropotassuril, Potassium monochloride, K-Contin, Kay Ciel, Steropotassium, K-Lease, Kalcorid, Kaleorid, Kaliduron, Kaliglutol, Kalilente, Kalinorm, Kaliolite, Kaon Cl, Kaon-Cl, Klorvess, Micro-K, Miopotasio, Potasion, Celeka, Durekal, Durules, Enpott
Molecular formula: ClK
Empirical formula: ClK
Molecular weight: 74.55 g/mol
Exact mass: 73.93256
CAS number: 7447-40-7
PubChem CID: 4873
Canonical SMILES: [Cl-].[K+]
Isomeric SMILES: [Cl-].[K+]
InChI: InChI=1S/ClH.K/h1H;/q;+1/p-1
InChIKey: WCUXLLCKKVVCTQ-UHFFFAOYSA-M
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity

Appearance: Colorless crystals[4]
5 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Potassium chloride appears as white colorless cubic crystals. Strong saline taste. (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
– Liquid; Other Solid; Liquid; CBI; Large Crystals; Wet Solid; Other Solid; Dry Powder [2] EPA Chemical Data Reporting (CDR)
– COLOURLESS HYGROSCOPIC CRYSTALS. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown Colorless crystals [4] Hazardous Substances Data Bank (HSDB)cites Schultz H et al; Potassium Compounds. Ullmann's Encyclopedia of Industrial Chemistry. 7th ed. (1999-2015). New York, NY: John Wiley & Sons. Online Posting Date: 15 Jun 2000
– Colorless, elongated, prismatic, or cubical crystals or as a white granular powder [4] Hazardous Substances Data Bank (HSDB)cites Osol, A. and J.E. Hoover, et al. (eds.). Remington's Pharmaceutical Sciences. 15th ed. Easton, Pennsylvania: Mack Publishing Co., 1975., p. 771
Odor: Odorless[4]
Melting point: 770 °C (1418 °F, NTP 1992)[1]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
770 °Cshown 1418 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
770 to 773 °C 770-773 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Boiling point: Reported, but no value passed the checks.
The 9 values and why
Sublimes at 2732 °F (NTP, 1992) (could not be read; source [1])
Sublimes 1500 °C (could not be read; source [4])
Specific heat = 693.7 J/kg-K (could not be read; source [4])
Heat of fusion = 337.7 kJ/mol (could not be read; source [4])
Enthalpy of formation = -436.7 kJ/mol (could not be read; source [4])
Entropy (S) = 82.55 J/mol-K (could not be read; source [4])
Dielectric constant (at 1X10+6 Hz) = 4.68 (could not be read; source [4])
Thermal coeff of expansion (15-25 °C) = 33.7X10-6/K (could not be read; source [4])
Boiling point of saturated solution at 1.013 bar = 108.6 °C (could not be read; source [4])
Density: 1.984 (NTP, 1992) - Denser than water[1]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
–shown 1.984 (NTP, 1992) - Denser than water [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
– 1.98 g/cm³ [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Solubility in water: Solubility in water at 20 °C: good[3]
3 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source
– greater than 100 mg/mL at 68 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
– For more Solubility (Complete) data for POTASSIUM CHLORIDE (6 total), please visit the HSDB record page. [4] Hazardous Substances Data Bank (HSDB)
–shown Solubility in water at 20 °C: good [3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	Potassium chloride appears as white colorless cubic crystals. Strong saline taste. (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–	Liquid; Other Solid; Liquid; CBI; Large Crystals; Wet Solid; Other Solid; Dry Powder	[2] EPA Chemical Data Reporting (CDR)
–	COLOURLESS HYGROSCOPIC CRYSTALS.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown	Colorless crystals	[4] Hazardous Substances Data Bank (HSDB)cites Schultz H et al; Potassium Compounds. Ullmann's Encyclopedia of Industrial Chemistry. 7th ed. (1999-2015). New York, NY: John Wiley & Sons. Online Posting Date: 15 Jun 2000
–	Colorless, elongated, prismatic, or cubical crystals or as a white granular powder	[4] Hazardous Substances Data Bank (HSDB)cites Osol, A. and J.E. Hoover, et al. (eds.). Remington's Pharmaceutical Sciences. 15th ed. Easton, Pennsylvania: Mack Publishing Co., 1975., p. 771

Value	As written	Source
770 °Cshown	1418 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
770 to 773 °C	770-773 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–shown	1.984 (NTP, 1992) - Denser than water	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–	1.98 g/cm³	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	greater than 100 mg/mL at 68 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–	For more Solubility (Complete) data for POTASSIUM CHLORIDE (6 total), please visit the HSDB record page.	[4] Hazardous Substances Data Bank (HSDB)
–shown	Solubility in water at 20 °C: good	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms: 2
Rings: 0
Aromatic rings: 0
Fraction sp³ carbons (Fsp3): 0
H-bond donors: 0
H-bond acceptors: 0 computed here · PubChem 1
Rotatable bonds: 0
TPSA (Å²): 0
Formal charge: 0
Complexity: 2 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: Kh of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

Cl47.56%
K52.44%

Isotope pattern

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P: -5.99 Crippen (Wildman and Crippen 1999)
log S (water solubility): 3.47 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 7.79 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 74.55
log P ≤ 5 (Crippen): -5.99
H-bond donors ≤ 5: 0
H-bond acceptors ≤ 10: 0

Passes all four rules.

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

This chemical does not meet GHS hazard criteria for 94.3% (825 of 875) of all reports.[5]

First aid

Eyes: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. Immediately transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. Skin: Immediately flood affected skin with water while removing and isolating all contaminated clothing.[1]
Fresh air, rest.[3]
Rinse skin with plenty of water or shower.[3]
First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.[3]

Storage

Dry.[3]
Keep container tightly closed in a dry and well-ventilated place. Hygroscopic, keep in a dry place. Storage class (TRGS 510): Non combustible solids.[4]

Incompatibilities

An attempt to prepare permanganyl chloride by cautiously adding concn sulfuric acid to an intimate mixture of the salts at 0 °C in clean glass apparatus caused a violent explosion.[4]

Safety data sheets on the supplier’s page: Thermo Fisher Scientific, abcr GmbH, Aladdin Scientific.

Always read the supplier’s safety data sheet before working with it.

Spectra

RamanRRUFF Project

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

[1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
[2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
[3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[4]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[5]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[6]RRUFF Project · Linked only · via PubChem · retrieved 2026-10-14
·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
·Literature on PubChem

Data last updated 2026-10-14.