Sodium chlorate . Sodium chlorate is a chemical compound whose formula is NaClO3. In pure form, it is a white crystalline powder that is easily soluble in water ; it is also hygroscopic. Decomposes above 250 ° C to release oxygen and leave a residue of sodium chloride.
Summary
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- 1 Physical and Chemical Properties
- 1 Physical Properties.
- 2 Chemical properties.
- 2 Obtaining Form.
- 3 Main Applications
- 4 Human Toxicity of Sodium Chlorate
- 5 Sources
Physical and chemical properties
Physical Properties.
- Aggregation Status: Solid
- Form of presentation: White, colorless crystalline powder
- Density: 2500 kg / m3; 2.5 g / cm3
- Molar mass: 106.44 g / mol
- Melting point: 521.15 K (248 ° C)
- Boiling point: It does not have. It begins to decompose at 300 ºC, releasing oxygen.
- Specific gravity (water = 1): 2.49015º
- Refractive index: 1.57
Chemical properties.
- Solubility in water:0 g / 100 ml (20 ° C)
Obtaining Form.
Sodium chlorate
Sodium chlorate is produced from two commonly found raw materials: salt (NaCl, sodium chloride) and water (H2O), along with the use of large amounts of electrical energy. The manufacturing process includes the electrolysis of an acidified sodium chloride solution in a specially designed electrochemical cell.
First, the raw brine is treated to remove impurities like calcium and magnesium. Then, hydrochloric acid (HCl) is added to control pH and improve efficacy. Sodium bichromate is used as a catalyst to inhibit secondary electrochemical reactions and as a buffer for pH.
- NaCl + 3H2O + Electricity> NaClO3 + 3H2
- Salt + Water + Energy> Sodium Chlorate + Hydrogen Gas
Chlorine gas (Cl2) is formed at the anode while hydrogen gas (H2) is formed at the cathode. The chlorine is then hydrolyzed in a cell to turn it into a kind of hypochlorite that then reacts to form sodium chlorate.
The solution that leaves the electrochemical cell is known as cell liquor. This solution contains a high concentration of chlorate ions and other intermediate reaction products. The solution is treated to remove by-products such as hypochlorite.
The sodium chlorate crystals are then removed and the remaining liquor containing salt, chloride ions, and dichromate is placed back into the electrochemical cells. The crystals are washed and dried to form the final product. For certain customers, the crystals are dissolved in water and shipped as a liquid solution.
It can also be synthesized by passing chlorine gas through a sodium hydroxide solution . Then it is purified by crystallization.
Main Applications
Sodium chlorate is widely used in the pulp and paper industry to produce chlorine dioxide, which is used to whiten wood pulp to make better quality, green, white paper products. Pasta factories convert sodium chlorate into chlorine dioxide – an ecological bleaching agent. The process of using chlorine dioxide to bleach the paste is known as “ECF”; and bleached means “without elemental chlorine”.
It is also used as a non-selective herbicide. Phytotoxic for all green parts of the plant. It can also kill through root absorption. Sodium Chlorate can be used to control a wide variety of plants including morning glory, Canada thistle, Johnson grass, bamboo, gray grass, and St. John’s wort.
The herbicide is used primarily on uncultivated land for on-site treatment and for full control of vegetation in areas including roads, fenceways, and ditches.
Sodium chlorate is also used as a defoliant and desiccant to:
- Cotton
- Safflower
- Corn
- Linen
- Peppers
- Soy
- Sorghum
- Southern Peas
- Dry beans
- Rice
- Sunflowers
Also in combination with atrazine, which increases the persistence of the effect. When used in combination with 2,4-D, performance is improved. Sodium chlorate has a sterilizing effect on the soil. Mixing with other herbicides in aqueous solution is possible, to some extent, as long as they are not susceptible to oxidation.
Human Toxicity of Sodium Chlorate
Considering its oxidative nature, sodium chlorate can be very toxic if ingested in relatively large amounts, which can be fatal. Symptoms of acute poisoning are: abdominal pain, nausea, vomiting, diarrhea, paleness, decline, shortness of breath, unconsciousness, and collapse.
After prolonged exposure in an atmosphere of sodium chlorate powder, skin irritation, irritation to mucous membranes, eyes, nose and throat may occur.
The effect on oxidative hemoglobin leads to the formation of methemoglobin, which is followed by denaturation of the globin protein and a crosslinking of red cell membrane proteins and the resulting damage to membrane enzymes. This leads to increased membrane permeability, and severe hemolysis. Hemoglobin denaturation exceeds the capacity of the G6PD metabolic pathway. Furthermore, this enzyme is directly denatured by the reduction of chlorate in its activity.
Ascorbic acid and methylene blue therapy is frequently used in the treatment of methemoglobinemia. However, since methylene blue requires the presence of NADPH which requires the normal operation of the G6PD system, which is less effective than in other conditions characterized by oxidation of hemoglobin.
Results of severe acute hemolysis, with multiple organ failure, including kidney failure and DIC. In addition there is direct toxicity to the proximal renal tubule. Treatment will consist of exchange transfusion, peritoneal dialysis, or hemodialysis.
