SODIUM CHLORATE

CAS NO: 7775-09-9
EC NO: 231-887-4
Synonyms:
chlorate de sodium; SODIUM CHLORATE; Chloric acid, sodium salt; 7775-09-9; Asex; Polybor-chlorate; Chlorate de sodium; Chlorsaure; Tumbleleaf; Atlacide; Desolet; Kusatol; Rasikal; Sodakem; Tumbleaf; Chlorate salt of sodium; Dervan Oxycil; Travex; Defol; Fall; Soda chlorate; Drexel defol; Harvest-aid; Evau-super; Kusa-tohru; Weed Killer; B-Herbatox; Drop-Leaf; Granex O; Hibar C; Shed-A-leaf; Leafex 2; Leafex 3; Chlorsaure [German]; Ortho-C-1-Defoliant; Shed-A-Leaf "L"; Caswell No. 753; VAL-DROP; Natriumchloraat [Dutch]; Natriumchlorat [German]; Sodium chlorate [ISO]; Sodium chlorate solution; Chloric acid, sodium salt (1:1); Grain sorghum harvest-aid; Natrium chloraat [Dutch]; Natrium chlorat [German]; Sodium chlorate (NaClO3); UNII-T95DR77GMR; Sodium(chlorate de) [French]; CCRIS 9185; HSDB 732; Sodio (clorato di) [Italian]; Sodium (chlorate de) [French]; CHEBI:65242; United Chemical Defoliant No. 1; Chlorate de sodium [ISO-French]; Ortho C-1 defoliant & weed killer; EINECS 231-887-4; UN1495; UN2428; EPA Pesticide Chemical Code 073301; Sodium chlorate solution (50% or less); MFCD00003479; 11096-45-0; Natriumchloraat; Natriumchlorat; Natrium chlorat; Natrium chloraat; Sodium Chlorate Min; Sodium chlorate(V); Sodium(chlorate de), Sodio (clorato di); ACMC-20ajoo, Sodium (chlorate de); ClO3.Na; AC1LANJY; Sodium chlorate [UN1495] [Oxidizer]; AC1Q1VAS; DSSTox_CID_6025; DSSTox_RID_77987; T95DR77GMR; DSSTox_GSID_26025; NaClO3, high pressure, III; CHEMBL1559268; DTXSID7026025; 71368_FLUKA; CTK5E4859; Sodium chlorate, aqueous solution; Chloric acid, sodiumsalt (1:1); YZHUMGUJCQRKBT-UHFFFAOYSA-M; 71368_SIAL; Sodium chlorate [UN1495] [Oxidizer]; TRA-0175804; NCGC00091465-01; NCGC00259682-01; Sodium chlorate, aqueous solution [UN2428] [Oxidizer]; Sodium chlorate, aqueous solution [UN2428] [Oxidizer]; SODIUM CHLORATE (SEE ALSO WATER DISINFECTION BYPRODUCTS(SODIUM CHLORATE)); WATER DISINFECTION BYPRODUCTS(SODIUM CHLORATE) (SEE ALSO WATER DISINFECTION BYPRODUCTS(DIBROMOACETIC ACID)); sodyum klorat; sodyum klorate; sodıum klorat; sodıum klorate; sodium klorat; sodium klorate; sodium, chlorate; sodium chlorate; sodyum, klorat; sodyum klorat.; SODIUM CHLORATE; CHLORATE DE SODİUM; CHLORATE DE SODIUM; SODIUM CHLORATE; 7775-09-9; Chloric acid, sodium salt; Asex; Chlorate de sodium; Chlorsaure; Tumbleleaf; Atlacide; Desolet; Kusatol; Rasikal; Sodakem; Tumbleaf; Chlorate salt of sodium; Dervan; Oxycil; Travex; Defol; Fall; Soda chlorate,; Drexel defol; Harvest-ai; Evau-super; Kusa-tohru; Weed Killer; B-Herbatox; Drop-Leaf; Granex O; Hibar C ; Shed-A-leaf; Chlorate de sodium; SODIUM CHLORATE; SODİUM CHLORATE; Chlorate de sodium; Chlorate de Sodium

Sodium chlorate

Sodium chlorate
Skeletal formula of sodium chlorate
Sodium chlorate powder
Unit cell of sodium chlorate
Unit cell of sodium chlorate
Names
IUPAC name
Sodium chlorate
Other names
Sodium chlorate(V)
Identifiers
CAS Number    
7775-09-9 check
3D model (JSmol)    
Interactive image
ChEBI    
CHEBI:65242 ☒
ChemSpider    
22895 check
ECHA InfoCard    100.028.989 Edit this at Wikidata
EC Number    
231-887-4
KEGG    
C18765 check
MeSH    Sodium+chlorate
PubChem CID    
516902
RTECS number    
FO0525000
UNII    
T95DR77GMR check
UN number    1495, 2428
CompTox Dashboard (EPA)    
DTXSID7026025 Edit this at Wikidata
InChI[show]
SMILES[show]
Properties
Chemical formula    NaClO3
Molar mass    106.44 g mol−1
Appearance    Colorless or white solid, hygroscopic
Odor    Odorless
Density    2.49 g/cm3 (15 °C)[1]
2.54 g/cm3 (20.2 °C)[2]
Melting point    248–261 °C (478–502 °F; 521–534 K)
Boiling point    300–400 °C (572–752 °F; 573–673 K)
decomposes[1]
Solubility in water    79 g/100 mL (0 °C)
89 g/100 mL (10 °C)
105.7 g/100 mL (25 °C)
125 g/100 mL (40 °C)
220.4 g/100 mL (100 °C)[3]
Solubility    Soluble in glycerol, hydrazine, methanol
Slightly soluble in ethanol, ammonia[1]
Solubility in acetone    Sparingly soluble[1]
Solubility in glycerol    20 g/100 g (15.5 °C)[1]
Solubility in ethanol    14.7 g/100 g[1]
Vapor pressure    <0.35 mPa[2]
Magnetic susceptibility (χ)    −34.7·10−6 cm3/mol
Refractive index (nD)    1.515 (20 °C)[4]
Structure[5]
Crystal structure    cubic
Point group    P213
Lattice constant    
a = 6.57584 Å
Formula units (Z)    4
Thermochemistry
Heat capacity (C)    104.6 J/mol·K[1]
Std molar
entropy (So298)    129.7 J/mol·K[1]
Std enthalpy of
formation (ΔfH⦵298)    -365.4 kJ/mol[1]
Gibbs free energy (ΔfG˚)    -275 kJ/mol[1]
Hazards
Safety data sheet    ICSC 1117
GHS pictograms    GHS03: OxidizingGHS07: HarmfulGHS09: Environmental hazard[6]
GHS Signal word    Danger
GHS hazard statements    H271, H302, H411[6]
GHS precautionary statements    P220, P273[6]
NFPA 704 (fire diamond)    
NFPA 704 four-colored diamond
023OX
Flash point    Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (median dose)    6500 mg/kg (rats, oral)
700 mg/kg (dogs, oral)[1]
Related compounds
Other anions    Sodium chloride
Sodium hypochlorite
Sodium chlorite
Sodium perchlorate
Sodium bromate
Sodium iodate
Other cations    Ammonium chlorate
Potassium chlorate
Barium chlorate
Related compounds    Chloric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒ verify (what is check☒ ?)
Infobox references
Sodium chlorate is an inorganic compound with the chemical formula NaClO3. It is a white crystalline powder that is readily soluble in water. It is hygroscopic. It decomposes above 300 °C to release oxygen[4] and leaves sodium chloride. Several hundred million tons are produced annually, mainly for applications in bleaching pulp to produce high brightness paper.[7]

Synthesis
Industrially, sodium chlorate is produced by the electrolysis of a hot sodium chloride solution:[7]

NaCl + 3 H2O → NaClO3 + 3 H2
This reaction progresses in heat (at least 70 °C), and controlled pH. In lower temperature or with high pH another reaction progresses:[citation needed]

2 NaCl + H2O → NaClO + NaCl + H2
The sodium chlorate process is not to be confused with the Chloralkali process, which is an industrial process for the electrolytic production of sodium hydroxide and chlorine gas.

Uses
The main commercial use for sodium chlorate is for making chlorine dioxide (ClO2). The largest application of ClO2, which accounts for about 95% of the use of chlorate, is in bleaching of pulp. All perchlorate compounds are produced industrially by the oxidation of solutions of sodium chlorate by electrolysis.[7]

Herbicides
Sodium chlorate is used as a non-selective herbicide. It is considered phytotoxic to all green plant parts. It can also kill through root absorption.

Sodium chlorate may be used to control a variety of plants including morning glory, canada thistle, johnson grass, bamboo, Ragwort, and St John's wort. The herbicide is mainly used on non-crop land for spot treatment and for total vegetation control on areas including roadsides, fenceways, and ditches. Sodium chlorate is also used as a defoliant and desiccant for:

Cotton
Safflower
Corn
Flax
Peppers
Soybeans
Grain sorghum
Southern peas
Dry beans
Rice
Sunflowers
If used in combination with atrazine, it increases the persistence of the effect. If used in combination with 2,4-D, performance is improved. Sodium chlorate has a soil sterilant effect. Mixing with other herbicides in aqueous solution is possible to some extent, so long as they are not susceptible to oxidation.

The sale of sodium chlorate as a weedkiller was banned in the European Union in 2009 citing health dangers, with existing stocks to be used within the following year.[8]

Chemical oxygen generation
Chemical oxygen generators, such as those in commercial aircraft, provide emergency oxygen to passengers to protect them from drops in cabin pressure. Oxygen is generated by high-temperature decomposition of sodium chlorate:[9]

2 NaClO3 → 2 NaCl + 3 O2
Heat required to initiate this reaction is generated by oxidation of a small amount of iron powder mixed with the sodium chlorate, and the reaction consumes less oxygen than is produced. Barium peroxide (BaO2) is used to absorb the chlorine that is a minor product in the decomposition.[10] An ignitor charge is activated by pulling on the emergency mask. Similarly, the Solidox welding system used pellets of sodium chlorate mixed with combustible fibers to generate oxygen.

Oxygenless combustion
Sodium chlorate can be mixed with sucrose sugar to make a highly explosive fuel, similar to that of gunpowder, that burns in airtight spaces. This is the reaction:

8 NaClO3 + C12H22O11 → 8 NaCl + 12 CO2 + 11 H2O

However this sodium chlorate is mostly replaced by potassium chlorate.[citation needed]

Toxicity in humans
Sodium chlorate is toxic: "doses of a few grams of chlorate are lethal".[7] The oxidative effect on hemoglobin leads to methaemoglobin formation, which is followed by denaturation of the globin protein and a cross-linking of erythrocyte membrane proteins with resultant damage to the membrane enzymes. This leads to increased permeability of the membrane, and severe hemolysis. The denaturation of hemoglobin overwhelms the capacity of the G6PD metabolic pathway. In addition, this enzyme is directly denatured by chlorate.

Acute severe hemolysis results, with multi-organ failure, including DIC and kidney failure. In addition there is a direct toxicity to the proximal renal tubule.[11] The treatment will consist of exchange transfusion, peritoneal dialysis or hemodialysis.[12]

Formulations
Sodium chlorate comes in dust, spray and granule formulations. Mixtures of chlorates and organic compounds pose a severe risk of explosions[13]

Marketed formulations contain a fire retardant. Most commercially available chlorate weedkillers contain approximately 53% sodium chlorate with the balance being a fire depressant such as sodium metaborate or ammonium phosphates.

Trade names
Sodium chlorate is the active ingredient in a variety of commercial herbicides. Some trade names for products containing sodium chlorate include Atlacide, Defol, De-Fol-Ate, Drop-Leaf, Fall, Harvest-Aid, Kusatol, Leafex, and Tumbleaf. The compound may be used in combination with other herbicides such as atrazine, 2,4-D, bromacil, diuron, and sodium metaborate.

Sodium chlorate was an extensively used weed killer within the EU, until 2009 when it was withdrawn after a decision made under terms of EU Regulations. Its use as a herbicide outside the EU remains unaffected, as does its use in other non-herbicidal applications, such as in the production of chlorine dioxide biocides and for pulp and paper bleaching.

Cultural references
Historian James Watson of Massey University in New Zealand wrote a widely reported article, "The Significance of Mr. Richard Buckley's Exploding Trousers"[14][15] about accidents with sodium chlorate when used as a herbicide to control ragwort in the 1930s.[16] This later won him an Ig Nobel Prize in 2005,[17] and was the basis for the May 2006 "Exploding Pants" episode of MythBusters.

Sodium chlorate is an inorganic compound with the chemical formula NaClO3. It is a white crystalline powder that is readily soluble in water. It is hygroscopic. It decomposes above 300 °C to release oxygen and leave sodium chloride. Several hundred million tons are produced annually, mainly for applications in bleaching paper.

Uses
The main commercial use for sodium chlorate is for making chlorine dioxide (ClO2). The largest application of ClO2, which accounts for about 95% of the use of chlorate, is in bleaching of pulp. All perchlorate compounds are produced industrially by the oxidation of solutions of sodium chlorate by electrolysis.

Herbicides
Sodium chlorate is used as a non-selective herbicide. It is considered phytotoxic to all green plant parts. It can also kill through root absorption.

Sodium chlorate may be used to control a variety of plants including morning glory, canada thistle, johnson grass, bamboo, Ragwort, and St John's wort. The herbicide is mainly used on non-crop land for spot treatment and for total vegetation control on areas including roadsides, fenceways, and ditches. Sodium chlorate is also used as a defoliant and desiccant for:

CottonSafflower-Corn-Flax-Peppers-Soybeans-Grain sorghum-Southern peas-Dry beans-Rice-Sunflowers

If used in combination with atrazine, it increases the persistence of the effect. If used in combination with 2,4-D, performance is improved. Sodium chlorate has a soil sterilant effect. Mixing with other herbicides in aqueous solution is possible to some extent, so long as they are not susceptible to oxidation.

Trade names
Sodium chlorate is the active ingredient in a variety of commercial herbicides. Some trade names for products containing sodium chlorate include Atlacide, Defol, De-Fol-Ate, Drop-Leaf, Fall, Harvest-Aid, Kusatol, Leafex, and Tumbleaf. The compound may be used in combination with other herbicides such as atrazine, 2,4-D, bromacil, diuron, and sodium metaborate.

Sodium chlorate was an extensively used weedkiller within the EU, up until 2009 when it was withdrawn after a decision made under terms of EU Regulations. Its use as an herbicide outside the EU remains unaffected, as does its use in other non-herbicidal applications, such as in the production of chlorine dioxide biocides and for pulp and paper bleaching

Industry Uses
Bleaching agents
Fuels and fuel additives
Intermediates
Oxidizing/reducing agents
Processing aids, specific to petroleum production
Solvents (for cleaning or degreasing)

Sodium chlorate can be made by the electrolysis of a hot, acidified solution of sodium chloride. While lots of people are correctly suggesting carbon or graphite electrodes, when I did it some decades ago, I used steel cathodes and carbon anodes, stainless cathodes would be even better. Industrially, titanium coated with platinum group metal oxides are used as anodes. Forget that, they make gold look like a bargain, use carbon and change as needed. Electrodes should be as close as you can get them without actually touching. Current density of about 0.2A/cm2. pH of 6 (use HCl to acidify). About 3V is needed for industrial electrodes, I cannot for the life of me remeber what I used 35 years ago, but probably similar. Separating the sodium chlorate from the remaining sodium chloride and getting it pure is the tedious part. Easiest is to can dump a lot of salt in your cell, once the reaction progresses and sodium chlorate saturates, it will start to crystalise out. If you don't get the conditions correct, you can easily produce sodium hypochlorite. Industrially, chromate is added to suppress that reaction. Chromate is very toxic stuff that you should avoid if your chemistry schooling is from instructables.

Chemical formula: NaClO3
Molecular weight: 106.4 g/mole
Appearance: white to off-white crystalline material, odorless
Melting point: 248 - 250 °C
Boiling point: none, is decomposed at temperatures higher than 250 - 300°C into sodium chloride and oxygen gas

Reactivity Profile
SODIUM CHLORATE decomposes upon heating forming O2; reacts with strong acids forming toxic and explosive ClO2; reacts with many substances [Handling Chemicals Safely 1980 p. 833]; metal chlorates are oxidants in the presence of strong acid; liberates explosive chlorine dioxide gas; heating a moist metal chlorate and a dibasic organic acid liberates chlorine dioxide and carbon dioxide; mixtures of perchlorates with sulfur or phosphorus are explosives [Bretherick 1979 p. 100]; mixtures of the chlorate with ammonium salts (ammonium thiosulfate), powdered metals, silicon, sulfur, or sulfides are readily ignited and potentially explosive [Bretherick 1979 p. 806]. A combination of finely divided aluminum with finely divided bromates(also chlorates and iodates) of barium, calcium, magnesium, potassium, sodium or zinc can explode by heat, percussion, and friction [Mellor 2:310 1946-47]. Sodium chlorate and arsenic trioxide form a spontaneously flammable mixture [Ellern 1968 p.

A chlorate candle is a device that produces oxygen when breathable air is scarce. Traditional wax candles spread soft haloes of light as they burn, a process that consumes oxygen from the air. Chlorate candles also burn, but their function is to release oxygen for emergency breathing.

First-responders must be prepared for many dangerous situations. Lack of oxygen is an immediate risk that can lead swiftly to death. That's when a chlorate candle can be a life-saver. These candles can be counted among the equipment carried by firefighters and mine rescue crews. They can also be found on submarines and air- and spacecraft.

Sodium chlorate appears as an odorless pale yellow to white crystalline solid. It is appreciably soluble in water and heavier, so may be expected to sink and dissolve at a rapid rate. Although it is not itself flammable, the solid product and even 30% solutions in water are powerful oxidizing agents. Contact with wood, organic matter, ammonium salts, sulfur, sulfuric acid, various metals, and other chemicals may result in fires or explosions, particularly if any solid materials are finely divided. Excessive heat, as in fires, may cause evolution of oxygen gas that may increase the intensity of fires and may also result in explosions. Mixtures with combustible materials are very flammable and may be ignited by friction. It is used for making herbicides, explosives, dyes, matches, inks, cosmetics, pharmaceuticals, defoliants, paper, and leather.

CAMEO Chemicals
Sodium chlorate is an inorganic sodium salt that has chlorate as the counter-ion. An oxidising agent, it is used for bleaching paper and as a herbicide. It is also used in the manufacture of dyes, explosives and matches. It has a role as a herbicide. It is an inorganic sodium salt and a chlorate salt.

ChEBI
Sodium chlorate in a water solution is a clear colorless liquid. It is noncombustible but it can accelerate the burning of surrounding combustible materials. This can easily occur if the material should dry out. Contact with strong sulfuric acid may cause fires or explosions.

Help on calculated properties New window
Property name Property value Reference
Molecular weight of Sodium Chlorate: 106.44 g / mol calculated by PubChem 2.1 (PubChem release 2019.06.18)
Number of sodium chlorate hydrogen bond donors: 0 calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Number of hydrogen bond acceptors of Sodium Chlorate: 3 calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Number of Sodium Chlorate rotary bonds: 0 calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Exact mass of Sodium Chlorate: 105.943366 g / mol calculated by PubChem 2.1 (PubChem release 2019.06.18)
Monoisotopic mass of Sodium Chlorate: 105.943366 g / mol calculated by PubChem 2.1 (PubChem release 2019.06.18)
Topological polar surface of Sodium Chlorate: 57.2 Ų calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Number of heavy atoms of Sodium Chlorate: 5 calculated by PubChem
Formal charge of sodium chlorate: 0 calculated by PubChem
Complexity of Sodium Chlorate: 49.8 calculated by Cactvs 3.4.6.11 (PubChem release 2019.06.18)
Number of isotopic atoms of sodium chlorate: 0 calculated by PubChem
Defined number of atomic stereocenters of Sodium Chlorate: 0 calculated by PubChem
Number of undefined atomic stereocenter of Sodium Chlorate: 0 calculated by PubChem
Defined number of Sodium Chlorate bond stereocenters: 0 calculated by PubChem
Number of undefined binding stereocentre of sodium chlorate: 0 calculated by PubChem
Number of covalently bound units of Sodium Chlorate: 2 calculated by PubChem
The compound is canonized from Sodium Chlorate: Yes