Potassium chloride

Potassium chloride ;
Names:	potassium chloride; muriate of potash; MOP; Е508 food additive PubChem: 4873; CAS: 7447-40-7; CAS: 14336-88-0; InChI Key: WCUXLLCKKVVCTQ-UHFFFAOYSA-M;
Formula:	KCl;
SMILES:	[Cl-].[K+];
Molar mass:	74.551 g/mol;
Density:	1.988 g/cm3;
Crystal system:	cubic; a=6.29294 Å, b=6.29294 Å, c=6.29294 Åα=90°, β=90°, γ=90°;
Shapes:	https://media.crystalls.info/w/uploads/media/Cube.json Cube https://media.crystalls.info/w/uploads/media/Tetragonal_prism.json Tetragonal prism https://media.crystalls.info/w/uploads/media/Tetragonal_flat_prism.json Tetragonal flat prism https://media.crystalls.info/w/uploads/media/Tetragonal_pedion.json Tetragonal pedion https://media.crystalls.info/w/uploads/media/Needle.json Needle ;
Color:	colorless;
Melting point:	776 °C1,049.15 K <br />1,428.8 °F <br />1,888.47 °R <br />;
Boiling point:	1420 °C1,693.15 K <br />2,588 °F <br />3,047.67 °R <br />;
Refractive index:	1.4902 ;
Magnetic properties:	diamagnetic; χ=-3.90 · 10-5cm³/mol;
Radiation properties:	slightly radioactive;
Stability:	stable;
Hardness:	strong; (2.5 on Moh's scale);
Toxicity:	non-toxic; LD50=2600mg/kg

<amp/>

Description

Inorganic compound, salt of alkaline metal potassium and inorganic hydrochloric acid. Doesn't form water hydrates.

Minerals

Occurs in nature as sylvite, sylvinite and carnallite minerals.

Where to buy

In fertilizers store (as "muriate of potash") and grocery store (as "salt with a reduced sodium content", mixture with sodium chloride in 1:1 ratio).

Precursors

Reaction between potassium hydroxide or carbonate and hydrochloric acid

Chemical equation:

HCl + KOH = KCl + H₂O

2HCl + K₂CO₃ = 2KCl + H₂O + CO₂↑

For preparation of 100.00g of potassium chloride а 75.26g of potassium hydroxide or 92.69g of carbonate and 128.70g of 38%38% hydrochloric acid is required.

Add acid to the flask, then add small parts of potassium compound with stirring until it will totally dissolve or, if you use carbonate, until carbon dioxide emission will stop. After reaction will stop, filter the solution and use it for crystal growing.

Recrystallization of "salt with a lower sodium content"

Add potassium and sodium chlorides mixture to the flask with boiling water until solution become saturated. Then filter out the solution and cool slowly. Excess of compound precipitates as a crystalline precipitate, most of impurities remain in the solution.

Separate this precipitate from the stock solution, and repeat this process for several times, use the same solution at each next step. Finally, the precipitated compound is used for crystal growing.

Influence of temperature

Temperature increase leads to changing crystals shape to long thin needles.

Temperature	гр/`100,00` гр water	гр/`100,00` гр ethanol	гр/`100,00` гр methanol	гр/`100,00` гр glycerol	гр/`100,00` гр furfural	гр/`100,00` гр ethylene glycol	гр/`100,00` гр formic acid 95%	гр/`100,00` гр acetic acid	гр/`100,00` гр propanol	гр/`100,00` гр hydrazine	гр/`100,00` гр acetamide	гр/`100,00` гр dimethylformamide	гр/`100,00` гр N-methylformamide	гр/`100,00` гр formamide
0°C273.15 K <br />32 °F <br />491.67 °R <br />	`27.78`
10°C283.15 K <br />50 °F <br />509.67 °R <br />	`30.91`
15°C288.15 K <br />59 °F <br />518.67 °R <br />	`~32.5`	`0.0265`
20°C293.15 K <br />68 °F <br />527.67 °R <br />	`34.03`	`~0.03`					`19.4`	`0.195`		`9`
25°C298.15 K <br />77 °F <br />536.67 °R <br />	`36.01`	`0.0288`	`0.54`	`6.7`	`0.073`	`5.18`		`~0.21`	`0.004`		`2.45`	`0.05`	`2.1`	`6.2`
30°C303.15 K <br />86 °F <br />545.67 °R <br />	`37.47`	`~0.03`	`0.56`					`~0.22`
40°C313.15 K <br />104 °F <br />563.67 °R <br />	`40.31`	`0.0325`	`0.60`					`~0.24`
50°C323.15 K <br />122 °F <br />581.67 °R <br />	`43.05`	`0.039`	`0.63`					`~0.26`
60°C333.15 K <br />140 °F <br />599.67 °R <br />	`45.64`	`~0.04`	`0.67`					`0.285`
70°C343.15 K <br />158 °F <br />617.67 °R <br />	`48.33`	`~0.04`						`~0.34`
80°C353.15 K <br />176 °F <br />635.67 °R <br />	`50.85`	`0.049`						`~0.40`
90°C363.15 K <br />194 °F <br />653.67 °R <br />	`53.82`							`0.457`
100°C373.15 K <br />212 °F <br />671.67 °R <br />	`56.37`

Slightly soluble in pyridine. Insoluble in acetone, acetonitrile and amyl alcohol.

Gallery

Video

Sources

Navigation

Chlorides
Salts	Ammonium chloride (NH₄Cl) • Barium chloride (BaCl₂) • Calcium chloride (CaCl₂) • Cadmium chloride (CdCl₂) • Cobalt(II) chloride (CoCl₂) • Copper(II) chloride (CuCl₂) • Iron(II) chloride (FeCl₂) • Iron(III) chloride (FeCl₃) • Lead(II) chloride (PbCl) • Manganese(II) chloride (MnCl₂) • Potassium chloride (KCl) • Sodium chloride (NaCl) • Strontium chloride (SrCl₂) • Tin(II) chloride (SnCl₂) • Zirconyl chloride (ZrOCl₂)
Double salts	Rubidium-gold(III)-palladium(II) chloride (2RbCl · AuCl₃ · PdCl₂)
Adducts	Diglycine hydrochloride (2NH₂CH₂COOH · HCl) • Glutamic acid hydrochloride (C₅H₉NO₄ · HCl) • Glucose and sodium chloride complex (2C₆H₁₂O₆ · NaCl) • Hydroxylammonium chloride (NH₂OH · HCl) • P-nitroaniline hydrochloride (C₆H₆N₂O₂ · HCl) • Urea and sodium chloride complex (CO(NH₄)₂ · NaCl)
Complexes	Ammonium pentachloroferrate(III) ((NH₄)₂[FeCl₅]) • Ammonium tetrachlorocuprate(II) ((NH₄)₂[CuCl₄]) • Lithium trioxalatoferrate(III)-chloride (Li₄[Fe(C₂O₄)₃]Cl) • Hexamminecobalt(III) chloride ([Co(NH₃)₆]Cl₂) • Hexaamminenickel chloride ([Ni(NH₃)₆]Cl₂) • Potassium hexachlororhodate(III) (K₃[RhCl₆])

Potassium compounds
Salts	Potassium bromate (KBrO₃) • Potassium bromide (KBr) • Potassium chlorate (KClO₃) • Potassium chloride (KCl) • Potassium chromate (K₂CrO₄) • Potassium dihydrophosphate (KH₂PO₄) • Potassium dichromate (K₂Cr₂O₇) • Potassium iodide (KI) • Potassium hydrofluoride (KHF₂) • Potassium hydrophosphate (K₂HPO₄) • Potassium hydrophthalate (KC₈H₆O₄) • Potassium metavanadate (KVO₃) • Potassium nitrate (KNO₃) • Potassium sulfate (K₂SO₄) • Potassium thiocyanate (KNCS)
Double salts	Aluminum-potassium sulfate (KAl(SO₄)₂) • Antimony(III)-potassium tartrate (K₂Sb₂(C₄H₂O₆)₂) • Chromium(III)-potassium sulfate (KCr(SO₄)₂) • Cobalt(II)-potassium sulfate (K₂Co(SO₄)₂) • Copper(II)-potassium sulfate (K₂Cu(SO₄)₂) • Indium(III)-potassium sulfate (KIn(SO₄)₂) • Iron(II)-potassium sulfate (K₂Fe(SO₄)₂) • Iron(III)-potassium sulfate (KFe(SO₄)₂) • Lithium-potassium sulfate (KLiSO₄) • Magnesium-potassium sulfate (K₂Mg(SO₄)₂) • Magnesium-potassium sulfate-chromate (K₂CrO₄ · MgSO₄) • Manganese(II)-potassium sulfate (K₂Mn(SO₄)₂) • Nickel-potassium sulfate (K₂Ni(SO₄)₂) • Potassium-sodium tartrate (KNaC₄H₄O₆) • Vanadium(III)-ammonium sulfate (NH₄V(SO₄)₂)
Complexes	Potassium dioxalatocuprate(II) (K₂[Cu(C₂O₄)₂]) • Potassium hexanitrocobaltate(III) (K₃[Co(NO₂)₆]) • Potassium hexachlororhodiate(III) (K₃[RhCl₆]) • Potassium hexacyanocobaltate(III) (K₃[Co(CN)₆]) • Potassium hexacyanoferrate(II) (K₄[Fe(CN)₆]) • Tripotassium-sodium hexacyanoferrate(II) (K₃Na[Fe(CN)₆]) • Potassium hexacyanoferrate(III) (K₃[Fe(CN)₆]) • Potassium hexacyanochromate(III) (K₃[Co(CN)₆]) • Potassium tetraiodobismuthate (К[BiI₄]) • Potassium tetraiodomercurate(II) (K₂[HgI₄]) • Potassium trioxalatoaluminate (K₃[Al(C₂O₄)₃]) • Potassium trioxalatocobaltate(III) (K₃[Co(C₂O₄)₃]) Potassium trioxalatoferrate(III) (K₃[Fe(C₂O₄)₃]) • Potassium-sodium trioxalatoferrate(III) (K₅Na[Fe(C₂O₄)₃]₂) • Dipotassium-sodium trioxalatoferrate(III) (K₂Na[Fe(C₂O₄)₃]) • Potassium trioxalatochromate(III) (K₃[Cr(C₂O₄)₃])

Potassium chloride
Names:	potassium chloride muriate of potash MOP Е508 food additive PubChem: 4873 CAS: 7447-40-7 CAS: 14336-88-0 InChI Key: WCUXLLCKKVVCTQ-UHFFFAOYSA-M
Formula:	KCl
SMILES:	[Cl-].[K+]
Molar mass:	74.551 g/mol
Density:	1.988 g/cm³
Crystal system:	cubic a=6.29294 Å, b=6.29294 Å, c=6.29294 Åα=90°, β=90°, γ=90°
Shapes:	Cube Tetragonal prism Tetragonal flat prism Tetragonal pedion Needle
Color:	colorless
Melting point:	776 °C1,049.15 K <br />1,428.8 °F <br />1,888.47 °R <br />
Boiling point:	1420 °C1,693.15 K <br />2,588 °F <br />3,047.67 °R <br />
Refractive index:	1.4902
Magnetic properties:	diamagnetic χ=-3.90 · 10^-5cm³/mol
Radiation properties:	slightly radioactive
Stability:	stable
Hardness:	strong (2.5 on Moh's scale)
Toxicity:	non-toxic LD₅₀=2600mg/kg