Sodium chlorate crystals
| IUPAC name
| Other names
|Molar mass||106.44 g/mol|
|Appearance||White crystalline solid|
|Density|| 2.49 g/cm3 (15 °C)|
2.54 g/cm3 (20.2 °C)
|Melting point||248 °C (478 °F; 521 K)|
| 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|
Std enthalpy of
|Safety data sheet||Sigma-Aldrich|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
| 6,500 mg/kg (rat, oral)|
700 mg/kg (dog, oral)
| Sodium hypochlorite|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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.
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
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.
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.
Its sale is banned in the EU.
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
- 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. 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.
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.
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.
Sodium chlorate can be neutralized with acidified sodium or potassium metabisulfite.