Sodium chlorate
 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 | |
| Std molar
entropy (S |
129.7 J·mol-1·K-1 |
| Std enthalpy of
formation (ΔfH |
-365.4 kJ/mol |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
| LD50 (Median dose)
|
6,500 mg/kg (rats, oral) 700 mg/kg (dogs, 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.
Contents
Properties
Chemical
It is a strong oxidizing agent, easily supplying oxygen to combustibles. It decomposes above 300 °C yeilding 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.
Availability
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.
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.[1] 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.
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 sodium or potassium metabisulfite.
