Difference between revisions of "Sodium chlorate"

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'''Sodium chlorate''' is an inorganic compound, comprised of equal numbers of sodium cations and [[chlorate]] anions, giving it the fomula NaClO<sub>3</sub>.
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{{distinguish|Sodium chlorite}}
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{{Chembox
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| Name = Sodium chlorate
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| Reference =
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| IUPACName = Sodium chlorate
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| PIN =
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| SystematicName =
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| OtherNames = Asex<br>Polybor-chlorate<br>Sodium chlorate(V)
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| ImageFile = Sodium chlorate crystals.jpg
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| ImageSize = 300
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| ImageCaption = Sodium chlorate crystals
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| Section1 = {{Chembox Identifiers
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| 3DMet =
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| Abbreviations =
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| SMILES =
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  }}
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| Section2 = {{Chembox Properties
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| AtmosphericOHRateConstant =
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| Appearance = White crystalline solid
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| BoilingPt =
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| BoilingPtC =
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| BoilingPt_ref =
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| BoilingPt_notes = Decomposes
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| Density = 2.49 g/cm<sup>3</sup> (15 °C)<br> 2.54 g/cm<sup>3</sup> (20.2 °C)
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| Formula = NaClO<sub>3</sub>
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| HenryConstant =
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| LogP =
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| MolarMass = 106.44 g/mol
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| MeltingPt =
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| MeltingPtC = 248
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| MeltingPt_ref =
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| MeltingPt_notes =
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| Odor = Odorless
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| pKa =
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| pKb =
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| Solubility = 79 g/100 ml (0 °C)<br>89 g/100 ml (10 °C)<br>105.7 g/100 ml (25 °C)<br>125 g/100 ml (40 °C)<br>220.4 g/100 ml (100 °C)
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| SolubleOther = Soluble in [[glycerol]], [[hydrazine]], [[methanol]]<br> Slightly soluble in liq. [[ammonia]], [[ethanol]]<br>Sparingly soluble in [[acetone]]<br>Insoluble in hydrocarbons
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| Solubility1 = 14.7 g/100 g
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| Solvent1 = ethanol
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| Solubility2 = 16 g/100 g (25 °C)
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| Solvent2 = ethylene glycol
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| Solubility3 = 20 g/100 g (15.5 °C)
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| Solvent3 = glycerol
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| Solubility4 = 66 g/100 g (25 °C)
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| Solvent4 = hydrazine
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| Solubility5 = 51.35 g/100 g (25 °C)
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| Solvent5 = methanol
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| VaporPressure = ~ 0 mmHg
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| Coordination =
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| CrystalStruct = Cubic
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| MolShape =
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| Section4 = {{Chembox Thermochemistry
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| DeltaGf = -275 kJ/mol
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| DeltaHc =
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| DeltaHf = -365.4 kJ/mol
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| Entropy = 129.7 J·mol<sup>-1</sup>·K<sup>-1</sup>
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| HeatCapacity = 104.6 J·mol<sup>-1</sup>·K<sup>-1</sup>
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  }}
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| Section5 = {{Chembox Explosive
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| ShockSens =
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| FrictionSens =
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| DetonationV =
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| REFactor =
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| Section6 = {{Chembox Hazards
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| AutoignitionPt = Non-flammable
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| ExploLimits =
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| ExternalMSDS = [https://www.docdroid.net/Z8VLpWn/sodium-chlorate-sa.pdf.html Sigma-Aldrich]
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| FlashPt = Non-flammable
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| LD50 = 6,500 mg/kg (rat, oral)<br>700 mg/kg (dog, oral)
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| LC50 =
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| MainHazards = Oxidizer<br>Harmful
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| Section7 = {{Chembox Related
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| OtherAnions =
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| OtherFunction =
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| OtherFunction_label =
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| OtherCompounds = [[Sodium hypochlorite]]<br>[[Sodium chlorite]]<br>[[Sodium perchlorate]]
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  }}
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}}
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'''Sodium chlorate''' is an inorganic compound, comprised of equal numbers of sodium cations and [[chlorate]] anions, giving it the fomula '''NaClO<sub>3</sub>'''. It is a very powerful oxidizer.
  
 
==Properties==
 
==Properties==
 
===Chemical===
 
===Chemical===
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It is a strong oxidizing agent, easily supplying oxygen to combustibles. It decomposes above 300 °C yeilding oxygen and [[sodium chloride]].
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It is a strong oxidizing agent, easily supplying oxygen to combustibles. It decomposes above 300 °C yielding oxygen and [[sodium chloride]].
  
 
:2 NaClO<sub>3</sub> → 2 NaCl + 3 O<sub>2</sub>
 
:2 NaClO<sub>3</sub> → 2 NaCl + 3 O<sub>2</sub>
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Sodium chlorate will react with potassium chloride to precipitate [[potassium chlorate]]:
 
Sodium chlorate will react with potassium chloride to precipitate [[potassium chlorate]]:
  
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:KCl + NaClO<sub>3</sub> → NaCl + KClO<sub>3</sub>
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: KCl + NaClO<sub>3</sub> → NaCl + KClO<sub>3</sub>
  
 
===Physical===
 
===Physical===
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Sodium chlorate is a colorless or white crystalline solid with a cubic crystal structure. It is soluble in water, methanol, glycerol, hydrazine and slightly soluble in ethanol and ammonia. Because sodium chlorate is [[Hygroscopy|hygroscopic]], potassium chlorate is often preferred for use as an oxidizer.
 
Sodium chlorate is a colorless or white crystalline solid with a cubic crystal structure. It is soluble in water, methanol, glycerol, hydrazine and slightly soluble in ethanol and ammonia. Because sodium chlorate is [[Hygroscopy|hygroscopic]], potassium chlorate is often preferred for use as an oxidizer.
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Sodium chlorate crystals are chiral, and both enantiomorphic (R/L) forms crystallize from solution in roughly equal proportions. Seeding with a selected enantiomorphic form leads to enrichment in that form. The presence of D-glucose or other chiral sugars skews the proportion of the two forms during crystallization. This is only a solid state effect due to the crystal structure, and in solution no enantiomers or optical activity can be observed. Big crystals can be sorted by hand using polarizing filters into their respective enantiomorphs.<ref>''Gmelins Handbuch der anorganischen Chemie, Natrium'', Verlag Chemie GmbH, Berlin, 8th edition '''1928''', p. 401</ref>
  
 
==Availability==
 
==Availability==
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It can be bought as "weed killer" at a hardware store, or it can be bought online. Many countries, however, have banned sodium chlorate weed killers.
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It can be bought as "weed killer" at a hardware store, or it can be bought online. Some brands may be adulterated with sodium chloride; in this case, the weed killer cannot be used as a reagent as is, but can be used as a raw material to prepare [[potassium chlorate]]. Many countries, however, have banned sodium chlorate weed killers.
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Its sale is banned in the EU.
  
 
==Preparation==
 
==Preparation==
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Sodium chlorate can be produced by boiling bleach, which causes it to disproportionate into sodium chlorate and sodium chloride.
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Sodium chlorate can be produced by boiling [[bleach]], which causes it to disproportionate into sodium chlorate and sodium chloride.
  
 
A more efficient way of producing sodium chlorate is via the electrolysis of a supersaturated sodium chloride solution with an appropriate anode at ~5 volts DC.
 
A more efficient way of producing sodium chlorate is via the electrolysis of a supersaturated sodium chloride solution with an appropriate anode at ~5 volts DC.
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Although the exact reactions are very complex, the basic overall equation is:
 
Although the exact reactions are very complex, the basic overall equation is:
  
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:NaCl + 3 H<sub>2</sub>O → NaClO<sub>3</sub> + 3 H<sub>2</sub>
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: NaCl + 3 H<sub>2</sub>O → NaClO<sub>3</sub> + 3 H<sub>2</sub>
  
 
==Projects==
 
==Projects==
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Due to its oxidative nature, sodium chlorate can be very toxic if ingested. The oxidative effect on [http://en.wikipedia.org/wiki/Hemoglobin hemoglobin] leads to [http://en.wikipedia.org/wiki/Methaemoglobin methaemoglobin] formation, which is followed by [http://en.wikipedia.org/wiki/Denaturation_(biochemistry) denaturation] of the [http://en.wikipedia.org/wiki/Globin globin] protein and a [http://en.wikipedia.org/wiki/Cross-link cross-linking] of [http://en.wikipedia.org/wiki/Erythrocyte erythrocyte]membrane proteins with resultant damage to the membrane enzymes. This leads to increased permeability of the membrane, and severe [http://en.wikipedia.org/wiki/Hemolysis hemolysis]. The denaturation of hemoglobin overwhelms the capacity of the [http://en.wikipedia.org/wiki/Glucose-6-phosphate_dehydrogenase G6PD] [http://en.wikipedia.org/wiki/Metabolic_pathway metabolic pathway]. In addition, this enzyme is directly denatured by chlorate reducing its activity.
 
Due to its oxidative nature, sodium chlorate can be very toxic if ingested. The oxidative effect on [http://en.wikipedia.org/wiki/Hemoglobin hemoglobin] leads to [http://en.wikipedia.org/wiki/Methaemoglobin methaemoglobin] formation, which is followed by [http://en.wikipedia.org/wiki/Denaturation_(biochemistry) denaturation] of the [http://en.wikipedia.org/wiki/Globin globin] protein and a [http://en.wikipedia.org/wiki/Cross-link cross-linking] of [http://en.wikipedia.org/wiki/Erythrocyte erythrocyte]membrane proteins with resultant damage to the membrane enzymes. This leads to increased permeability of the membrane, and severe [http://en.wikipedia.org/wiki/Hemolysis hemolysis]. The denaturation of hemoglobin overwhelms the capacity of the [http://en.wikipedia.org/wiki/Glucose-6-phosphate_dehydrogenase G6PD] [http://en.wikipedia.org/wiki/Metabolic_pathway metabolic pathway]. In addition, this enzyme is directly denatured by chlorate reducing its activity.
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 +
Avoid contact with concentrated acids like sulfuric acid due to formation of highly reactive [[chloric acid]].
  
 
===Storage===
 
===Storage===
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===Disposal===
 
===Disposal===
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Sodium chlorate can be neutralized with sodium or potassium metabisulfite.
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Sodium chlorate can be neutralized with acidified sodium or potassium metabisulfite.
 +
 
 +
==Gallery==
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<gallery widths="200" position="center" columns="4" orientation="none">
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Sodium chlorate polarized.jpg|Crystals of sodium chlorate between two polarizing filters
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</gallery>
  
 
==References==
 
==References==
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*[http://www.sciencemadness.org/talk/viewthread.php?tid=15903 Sodium chlorate production questions]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=15903 Sodium chlorate production questions]
  
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[[Category:Chlorates]]
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[[Category:Chemical compounds]]
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[[Category:Inorganic compounds]]
 
[[Category:Sodium compounds]]
 
[[Category:Sodium compounds]]
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[[Category:Chlorates]]
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[[Category:Oxidizing agents]]

Latest revision as of 18:18, 3 February 2024

Not to be confused with Sodium chlorite.
Sodium chlorate
Sodium chlorate crystals.jpg
Sodium chlorate crystals
Names
IUPAC name
Sodium chlorate
Other names
Asex
Polybor-chlorate
Sodium chlorate(V)
Properties
NaClO3
Molar mass 106.44 g/mol
Appearance White crystalline solid
Odor Odorless
Density 2.49 g/cm3 (15 °C)
2.54 g/cm3 (20.2 °C)
Melting point 248 °C (478 °F; 521 K)
Boiling point Decomposes
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)
Solubility Soluble in glycerol, hydrazine, methanol
Slightly soluble in liq. ammonia, ethanol
Sparingly soluble in acetone
Insoluble in hydrocarbons
Solubility in ethanol 14.7 g/100 g
Solubility in ethylene glycol 16 g/100 g (25 °C)
Solubility in glycerol 20 g/100 g (15.5 °C)
Solubility in hydrazine 66 g/100 g (25 °C)
Solubility in methanol 51.35 g/100 g (25 °C)
Vapor pressure ~ 0 mmHg
Thermochemistry
129.7 J·mol-1·K-1
-365.4 kJ/mol
Hazards
Safety data sheet Sigma-Aldrich
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
6,500 mg/kg (rat, oral)
700 mg/kg (dog, oral)
Related compounds
Related compounds
 Sodium hypochlorite
Sodium chlorite
Sodium perchlorate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Sodium chlorate is an inorganic compound, comprised of equal numbers of sodium cations and chlorate anions, giving it the fomula NaClO3. It is a very powerful oxidizer.

Properties

Chemical

It is a strong oxidizing agent, easily supplying oxygen to combustibles. It decomposes above 300 °C yielding oxygen and sodium chloride.

2 NaClO3 → 2 NaCl + 3 O2

Sodium chlorate will react with potassium chloride to precipitate potassium chlorate:

KCl + NaClO3 → NaCl + KClO3

Physical

Sodium chlorate is a colorless or white crystalline solid with a cubic crystal structure. It is soluble in water, methanol, glycerol, hydrazine and slightly soluble in ethanol and ammonia. Because sodium chlorate is hygroscopic, potassium chlorate is often preferred for use as an oxidizer.

Sodium chlorate crystals are chiral, and both enantiomorphic (R/L) forms crystallize from solution in roughly equal proportions. Seeding with a selected enantiomorphic form leads to enrichment in that form. The presence of D-glucose or other chiral sugars skews the proportion of the two forms during crystallization. This is only a solid state effect due to the crystal structure, and in solution no enantiomers or optical activity can be observed. Big crystals can be sorted by hand using polarizing filters into their respective enantiomorphs.[1]

Availability

It can be bought as "weed killer" at a hardware store, or it can be bought online. Some brands may be adulterated with sodium chloride; in this case, the weed killer cannot be used as a reagent as is, but can be used as a raw material to prepare potassium chlorate. Many countries, however, have banned sodium chlorate weed killers.

Its sale is banned in the EU.

Preparation

Sodium chlorate can be produced by boiling bleach, which causes it to disproportionate into sodium chlorate and sodium chloride.

A more efficient way of producing sodium chlorate is via the electrolysis of a supersaturated sodium chloride solution with an appropriate anode at ~5 volts DC.

Although the exact reactions are very complex, the basic overall equation is:

NaCl + 3 H2O → NaClO3 + 3 H2

Projects

  • Preparation of potassium chlorate
  • Make a dry chemical oxygen generator: Heat 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 is used to absorb the chlorine which is a minor product in the decomposition.[2] 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.

Handling

Safety

Powerful oxidizer! Fire hazard! Keep away from any flammables.

Due to its oxidative nature, sodium chlorate can be very toxic if ingested. The oxidative effect on hemoglobin leads to methaemoglobin formation, which is followed by denaturation of the globin protein and a cross-linking of erythrocytemembrane 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 reducing its activity.

Avoid contact with concentrated acids like sulfuric acid due to formation of highly reactive chloric acid.

Storage

Sodium chlorate should be stored in closed bottles, away from any flammable materials and strong acids. Since it's hygroscopic, it should be kept in a dry place.

Disposal

Sodium chlorate can be neutralized with acidified sodium or potassium metabisulfite.

Gallery

  • Crystals of sodium chlorate between two polarizing filters

References

  1. ↑ Gmelins Handbuch der anorganischen Chemie, Natrium, Verlag Chemie GmbH, Berlin, 8th edition 1928, p. 401
  2. ↑ http://en.wikipedia.org/wiki/Sodium_chlorate#cite_note-8

Relevant Sciencemadness threads

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