Potassium chlorate

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Potassium chlorate

The structure of the ions in potassium chlorate

The crystal structure of potassium chlorate

Potassium chlorate crystals

Names
Other names

Potassium chlorate(V), Potcrate
Identifiers

CAS Number

  • 3811-04-9 checkY
3D model (

JSmol

)

  • Interactive image

ChemSpider

  • 18512

     checkY

ECHA InfoCard

100.021.173

Edit this at Wikidata

EC Number

  • 223-289-7

PubChem

CID

  • 6426889

RTECS number

  • FO0350000

UNII

  • H35KS68EE7

     checkY

UN number

1485

CompTox Dashboard

(EPA)

  • DTXSID6047448

    Edit this at Wikidata

InChI

  • InChI=1S/ClHO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 checkY
    Key: VKJKEPKFPUWCAS-UHFFFAOYSA-M checkY
  • InChI=1/ClHO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1
    Key: VKJKEPKFPUWCAS-REWHXWOFAC

SMILES

  • [K+].[O-]Cl(=O)=O
Properties

Chemical formula

KClO3

Molar mass

122.55 g mol−1
Appearance white crystals or powder

Density

2.32 g/cm3

Melting point

356 °C (673 °F; 629 K)

Boiling point

400 °C (752 °F; 673 K) decomposes

[1]

Solubility in water

3.13 g/100 mL (0 °C)
4.46 g/100 mL (10 °C)
8.15 g/100 mL (25 °C)
13.21 g/100 mL (40 °C)
53.51 g/100 mL (100 °C)
183 g/100 g (190 °C)
2930 g/100 g (330 °C)

[2]

Solubility

soluble in

glycerol

negligible in

acetone

and liquid

ammonia

[1]

Solubility

in

glycerol

1 g/100 g (20 °C)

[1]

Magnetic susceptibility

(χ)

−42.8·10−6 cm3/mol

Refractive index

(nD)

1.40835
Structure

Crystal structure

monoclinic
Thermochemistry

Heat capacity

(C)

100.25 J/mol·K

[1]

Std molar
entropy

(So298)

142.97 J/mol·K

[3]

[1]

Std enthalpy of
formation

fH298)

−391.2 kJ/mol

[3]

[1]

Gibbs free energy

fG˚)

-289.9 kJ/mol

[1]

Hazards

Safety data sheet

ICSC 0548

GHS pictograms

GHS03: Oxidizing

GHS07: Harmful

GHS09: Environmental hazard

[4]

GHS Signal word

Danger

GHS hazard statements

H271, H302, H332, H411

[4]

GHS precautionary statements

P220, P273

[4]

NFPA 704

(fire diamond)

2

0

3

OX

Lethal dose or concentration (LD, LC):
LD50 (

median dose

)

1870 mg/kg (oral, rat)

[5]

Related compounds
Other

anions

Potassium bromate

Potassium iodate

Potassium nitrate

Other

cations

Ammonium chlorate

Sodium chlorate

Barium chlorate

Related compounds

Potassium chloride

Potassium hypochlorite

Potassium chlorite

Potassium perchlorate

Except where otherwise noted, data are given for materials in their

standard state

(at 25 °C [77 °F], 100 kPa).

checkY 

verify

 (

what is

 checkY☒N ?)

Infobox references

Chemical compound

Potassium chlorate is a compound containing

potassium

,

chlorine

and

oxygen

, with the molecular formula KClO3. In its pure form, it is a white crystalline substance. It is the most common

chlorate

in industrial use. It is used,

  • as an

    oxidizing agent

    ,

  • to prepare

    oxygen

    ,

  • as a

    disinfectant

    ,

  • in safety

    matches

    ,

  • in

    explosives

    and

    fireworks

    ,

  • in

    cultivation

    , forcing the blossoming stage of the

    longan

    tree, causing it to produce fruit in warmer climates.

    [6]

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Production[

edit

]

On the industrial scale, potassium chlorate is produced by the Liebig process: passing chlorine through a hot suspension of

calcium hydroxide

in water, subsequently adding

potassium chloride

:

[7]

6 Ca(OH)2 + 6 Cl2 → Ca(ClO3)2 + 5 CaCl2 + 6 H2O
Ca(ClO3)2 + 2 KCl → 2 KClO3 + CaCl2

The

electrolysis

of

KCl

in aqueous solution is also used sometimes, in which elemental chlorine formed at the

anode

react with KOH

in situ

. The low

solubility

of KClO3 in water causes the salt to conveniently isolate itself from the

reaction mixture

by simply precipitating out of solution.

Potassium chlorate can be produced in small amounts by

disproportionation

in a

sodium hypochlorite

solution followed by

metathesis reaction

with potassium chloride:

[8]

3 NaOCl(aq) → 2 NaCl(s) + NaClO3(aq)
KCl(aq) + NaClO3(aq) → NaCl(aq) + KClO3(s)

It can also be produced by passing chlorine gas into a hot solution of caustic potash:

[9]

3 Cl2(g) + 6 KOH(aq) → KClO3(aq) + 5 KCl(aq) + 3 H2O(l)

Uses[

edit

]

Potassium chlorate burning sugar

Potassium chlorate was one key ingredient in early

firearms

percussion caps

(primers). It continues in that application, where not supplanted by

potassium perchlorate

.

Chlorate-based

propellants

are more efficient than traditional

gunpowder

and are less susceptible to damage by water. However, they can be extremely unstable in the presence of

sulfur

or

phosphorus

and are much more expensive. Chlorate propellants must be used only in equipment designed for them; failure to follow this precaution is a common source of accidents. Potassium chlorate, often in combination with

silver fulminate

, is used in trick

noise-makers

known as “crackers”, “snappers”, “pop-its”, or “bang-snaps”, a popular type of novelty

firework.

Another application of potassium chlorate is as the oxidizer in a

smoke composition

such as that used in

smoke grenades

. Since 2005, a cartridge with potassium chlorate mixed with

lactose

and

rosin

is used for generating the white smoke signaling the election of new pope by a

papal conclave

.

[10]

Potassium chlorate is often used in high school and college laboratories to generate oxygen gas.[

citation needed

] It is a far cheaper source than a pressurized or cryogenic oxygen tank. Potassium chlorate readily decomposes if heated while in contact with a

catalyst

, typically

manganese(IV) dioxide

(MnO2). Thus, it may be simply placed in a test tube and heated over a burner. If the test tube is equipped with a one-holed stopper and hose, warm oxygen can be drawn off. The reaction is as follows:

2 KClO3(s) → 3 O2(g) + 2 KCl(s)

Heating it in the absence of a catalyst converts it into

potassium perchlorate

:

[9]

4 KClO3 → 3 KClO4 + KCl

With further heating, potassium perchlorate decomposes to

potassium chloride

and oxygen:

KClO4 → KCl + 2 O2

The safe performance of this reaction requires very pure reagents and careful temperature control. Molten potassium chlorate is an extremely powerful oxidizer and spontaneously reacts with many common materials such as sugar. Explosions have resulted from liquid chlorates spattering into the latex or PVC tubes of oxygen generators, as well as from contact between chlorates and hydrocarbon sealing greases. Impurities in potassium chlorate itself can also cause problems. When working with a new batch of potassium chlorate, it is advisable to take a small sample (~1 gram) and heat it strongly on an open glass plate. Contamination may cause this small quantity to explode, indicating that the chlorate should be discarded.

Potassium chlorate is used in

chemical oxygen generators

(also called chlorate candles or oxygen candles), employed as oxygen-supply systems of e.g. aircraft, space stations, and submarines, and has been responsible for at least one

plane crash

. A fire on the space station

Mir

was also traced to this substance. The decomposition of potassium chlorate was also used to provide the oxygen supply for

limelights

.

Potassium chlorate is used also as a

pesticide

. In Finland it was sold under trade name Fegabit.

Potassium chlorate can react with sulfuric acid to form a highly reactive solution of chloric acid and potassium sulfate:

2 KClO3 + H2SO4 → 2 HClO3 + K2SO4

The solution so produced is sufficiently reactive that it spontaneously ignites if combustible material (sugar, paper, etc.) is present.

In schools, molten potassium chlorate is used in the dramatic

screaming jelly babies

,

Gummy bear

,

Haribo

, and

Trolli

candy demonstration where the candy is dropped into the molten salt.

In chemical labs it is used to oxidize HCl and release small amounts of gaseous chlorine.

Insurgents in

Afghanistan

also use potassium chlorate extensively as a key component in the production of

improvised explosive devices

. When significant effort was made to reduce the availability of

ammonium nitrate

fertilizer in Afghanistan, IED makers started using potassium chlorate as a cheap and effective alternative. In 2013, 60% of IEDs in Afghanistan used potassium chlorate, making it the most common ingredient used in IEDs.

[11]

Potassium chlorate was also the main ingredient in the car bomb used in

2002 Bali bombings

that killed 202 people.

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Safety[

edit

]

Potassium chlorate should be handled with care. It reacts vigorously, and in some cases spontaneously ignites or explodes, when mixed with many

combustible

materials. It burns vigorously in combination with virtually any combustible material, even those normally only slightly flammable (including ordinary dust and lint). Mixtures of potassium chlorate and a fuel can ignite by contact with sulfuric acid, so it should be kept away from this reagent.

Sulfur

should be avoided in pyrotechnic compositions containing potassium chlorate, as these mixtures are prone to spontaneous

deflagration

. Most sulfur contains trace quantities of sulfur-containing acids, and these can cause spontaneous ignition – “Flowers of sulfur” or “sublimed sulfur”, despite the overall high purity, contains significant amounts of sulfur acids. Also, mixtures of potassium chlorate with any compound with ignition promoting properties (ex.

antimony(III) sulfide

) are very dangerous to prepare, as they are extremely shock sensitive.

See also[

edit

]

  • Chloric acid

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References[

edit

]

  1. ^

    a

    b

    c

    d

    e

    f

    g

    “potassium chlorate”

    . Retrieved 9 July 2015.

  2. ^

    Seidell, Atherton; Linke, William F. (1952).

    Solubilities of Inorganic and Organic Compounds

    . Van Nostrand. Retrieved 2014-05-29.

  3. ^

    a

    b

    Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A22.

    ISBN

     

    0-618-94690-X

    .

  4. ^

    a

    b

    c

    “Potassium chlorate”

    . Retrieved 9 July 2015.

  5. ^

    Michael Chambers.

    “ChemIDplus – 3811-04-9 – VKJKEPKFPUWCAS-UHFFFAOYSA-M – Potassium chlorate – Similar structures search, synonyms, formulas, resource links, and other chemical information”

    . Retrieved 9 July 2015.

  6. ^

    Manochai, P.; Sruamsiri, P.; Wiriya-alongkorn, W.; Naphrom, D.; Hegele, M.; Bangerth, F. (February 12, 2005).

    “Year around off season flower induction in longan (Dimocarpus longan, Lour.) trees by KClO3 applications: potentials and problems”

    . Scientia Horticulturae. Department of Horticulture, Maejo University, Chiang Mai, Thailand; Department of Horticulture, Chiang Mai University, Chiang Mai, Thailand; Institute of Special Crops and Crop Physiology, University of Hohenheim, 70593 Stuttgart, Germany. 104 (4): 379–390.

    doi

    :

    10.1016/j.scienta.2005.01.004

    . Retrieved November 28, 2010.CS1 maint: location (

    link

    )

  7. ^

    Реми, Г. Курс неорганической химиию, т. 1/Перевод с немецкого под ред. А. В. Новосёловой. Москва:Мир, 1972.- с. 770//(translated from:) Heinrich Remy. Lehrbuch der anorganischen Chemie. XI Auflage. Band 1. Leipzig:Geest & Portig K.-G., 1960.

  8. ^

    Anne Marie Helmenstine, Ph.D.

    “Potassium Chlorate Synthesis (Substitute) Formula”

    . About.com Education. Retrieved 9 July 2015.

  9. ^

    a

    b

    Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002,

    ISBN

     

    0-07-049439-8

  10. ^

    Daniel J. Wakin and Alan Cowell (March 13, 2013).

    “New Round of Voting Fails to Name a Pope”

    .

    The New York Times

    . Retrieved March 13, 2013.

  11. ^

    “Afghan bomb makers shifting to new explosives for IEDs”

    . USAToday.com. June 25, 2013. Retrieved 2013-06-25.

  • “Chlorate de potassium. Chlorate de sodium”, Fiche toxicol. n° 217, Paris:Institut national de recherche et de sécurité, 2000. 4pp.
  • Continuous process for the manufacture of potassium chlorate by coupling with a sodium chlorate production plant

External links[

edit

]

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