How Sodium Chlorate Is Made and Used in Chemistry
The compound Sodium chlorate is an inorganic material with the standard equation NaClO3. Its physical properties include being white in color and having a crystalline nature that promptly dissolves in water. It has been known to be hygroscopic (absorbing moisture from the air) in nature. It decays over 573 Kelvin to discharge O2 and leave behind NaCl. Quite a lot of Sodium chlorate is created every year, mostly for various uses in the oxidizing mash to deliver a high-quality paper.
Properties
Physical properties of Sodium Chlorate
The physical properties of sodium chlorate are quite similar to other inorganic salts. Some of them are listed below-
It is an odourless compound.
Its color differs from light yellow to white crystalline solid.
It is very soluble in water and heavier than water. Hence, it can sink and break up at a fast rate.
While it is not an explosive by itself, yet it can cause powerful combustion on coming in contact with water. It causes a highly exothermic reaction. Even if 30% of molecules are in the water, they can cause a powerful oxidizing reaction due to their inherent properties.
Its density is 2.49 g/cm.
Sodium chlorate’s boiling point is 300 degrees C and the melting point is 248 degrees C.
It is also soluble in some organic solvents like glycerol and methanol. It is also slightly soluble in acetone.
It has a cubic crystal structure.
Chemical Properties of Sodium Chlorate
The chemical properties of sodium chlorate are very unique. Some of them are stated below-
It is a powerful oxidizing agent. The hypochlorite ion helps to oxidize and bleach any chemical.
It has a heat capacity of 104.6 Jmol/K.
Its reaction with potassium bromide and hydrochloric acid gives products as potassium chloride, sodium chloride, bromine, and water.
NaClO3 + 6KBr + 6HCl → 6KCl + NaCl + 3H2O + 3Br2
Its chemical reaction with potassium iodide and hydrochloric acid produces products as sodium chloride, potassium chloride, iodine, and water.
NaClO3 + 6KI + 6HCl → NaCl + 3I2 + 3H2O + 6KCl
It can react with many different chemical compounds such as other bromides and acids. When it is brought in close contact with wood, or any other similar material like sulphuric acid, different metals, and different synthetics, then it may cause flames or explosion.
Due to its explosive property caused by high oxidizing nature, it is kept separately and used in a controlled environment.
Preparation of Sodium Chlorate
Sodium chlorate is produced by the electrolysis of simple salty water (sodium chloride and water)
Sodium chlorate formula: NaCl + 3H2O + 6 e-→ NaClO3 + 3H2.
This process is exothermic in nature. It occurs in a number of steps. Also, the procedure is subject to pH and temperature alterations.
The preparation of sodium chlorate is quite simple, Chlorine gas (Cl2) is stored at the anode while hydrogen gas (H2) is stored at the cathode. Chlorine is then hydrolyzed in the cell to a hypochlorite anion group which at that point produces sodium chlorate.
Sodium chlorate particles are formed in the shape of crystals. The solution obtained after hydrolysis is often called cell liquor. The solution is then removed from the apparatus. The crystals obtained are washed and dried up and then stored in a dry area. Depending upon the use, it may be sold in crystals or sold as a liquid.
Sodium chlorate structure is given as follows:-
Sodium Chlorate Uses
Sodium chlorate is used for many purposes. Some common uses are given below-
It is utilized for making herbicides, explosives, colors, matches, inks, beautifiers, pharmaceuticals, defoliants, paper, and calfskin.
It is used as a dying mash in the creation of the paper.
Used in the Solvay process which uses up the salt along with H2SO4, and the presence of CH3OH as the lessening specialist.
It is used as an oxidizing specialist in the large scale dye-making processes and an oxidizing and bleaching operator.
It is used in the medical field for preparing different drugs.
It is used in making fertilizers and explosives.
Solved Examples
What happens when solid sodium chlorate is heated? Write a balanced chemical equation for this reaction.
On heating, Sodium chlorate decomposes into sodium chloride (solid) and oxygen (gas). The chemical equation for this reaction is:
2NaClO3+heat → 2NaCl + 3O2
What harmful effects can Sodium Chlorate have on the human body?
Exposure to sodium chlorate for a long time may have harmful effects on the human body. It can cause redness of the eyes and skin, sore throat, and abdominal pain. It can also cause blue lips or skin and medical conditions such as diarrhea, nausea, vomiting, shortness of breath, and unconsciousness.
FAQs on Sodium Chlorate: Preparation, Properties, and Applications
1. What is Sodium Chlorate, and what is its chemical formula?
Sodium Chlorate is an inorganic chemical compound with the formula NaClO₃. It is the sodium salt of chloric acid. In its solid form, it appears as a white, crystalline, odourless powder that is readily soluble in water. It is a powerful oxidizing agent and is valued for this property in many industrial applications.
2. How is Sodium Chlorate commercially prepared?
The primary industrial method for preparing Sodium Chlorate is through the electrolysis of a hot, concentrated aqueous solution of sodium chloride (brine). In this process, chlorine gas and sodium hydroxide are produced in-situ and react with each other under controlled high-temperature conditions (around 70°C) to form sodium chlorate and sodium chloride. The overall reaction is: 3Cl₂ + 6NaOH → NaClO₃ + 5NaCl + 3H₂O.
3. What are the key properties of Sodium Chlorate?
Sodium Chlorate exhibits several distinct physical and chemical properties. Key examples include:
- Appearance: It is a white or pale yellow crystalline solid.
- Solubility: It is highly soluble in water and glycerol, and moderately soluble in ethanol.
- Oxidizing Nature: It is a strong oxidizing agent, especially in acidic conditions. This is its most significant chemical property.
- Thermal Decomposition: When heated above 300°C, it decomposes to form sodium chloride and oxygen gas (2NaClO₃ → 2NaCl + 3O₂).
- Hygroscopic: It tends to absorb moisture from the air.
4. What are the main industrial applications of Sodium Chlorate?
The primary application of Sodium Chlorate is in the pulp and paper industry. Its major uses include:
- Bleaching Agent: About 95% of all sodium chlorate is used to produce chlorine dioxide (ClO₂), which is a key environmentally-friendly bleaching agent for wood pulp.
- Herbicides: It is used as a non-selective contact herbicide to control weeds, grasses, and brush on non-cropland areas like roadsides and industrial sites.
- Chemical Synthesis: It serves as an oxidizing agent in the manufacturing of other chemicals, such as perchlorates and chlorites.
- Explosives: In some formulations, it is used as an oxidizer in explosives and pyrotechnics.
5. Why is Sodium Chlorate considered such a powerful oxidizing agent?
Sodium Chlorate's strength as an oxidizing agent stems from the high oxidation state of the chlorine atom within the chlorate ion (ClO₃⁻). In this ion, chlorine has an oxidation state of +5. This is a relatively unstable, high-energy state for chlorine, which naturally prefers the more stable -1 oxidation state (as seen in chloride, Cl⁻). To achieve this stability, the chlorine atom readily accepts electrons from other substances, causing them to be oxidized. This strong tendency to gain electrons makes Sodium Chlorate a powerful oxidizing agent.
6. Is an aqueous solution of Sodium Chlorate acidic, basic, or neutral? Explain the reason.
An aqueous solution of Sodium Chlorate is neutral. This is because NaClO₃ is a salt formed from the reaction of a strong acid (chloric acid, HClO₃) and a strong base (sodium hydroxide, NaOH). When this salt dissolves in water, it dissociates into Na⁺ and ClO₃⁻ ions. Neither of these ions reacts with water (hydrolyzes) to a significant extent to alter the concentration of H⁺ or OH⁻ ions in the solution. Therefore, the solution remains neutral with a pH of approximately 7.
7. What is the fundamental difference between Sodium Chlorate (NaClO₃) and Sodium Chloride (NaCl)?
While their names are similar, Sodium Chlorate and Sodium Chloride are fundamentally different compounds.
- Chemical Composition: The most obvious difference is the presence of oxygen. Sodium Chloride (NaCl) contains only sodium and chlorine, whereas Sodium Chlorate (NaClO₃) contains sodium, chlorine, and three oxygen atoms.
- Chemical Properties: NaCl is common table salt, which is chemically very stable and essential for life. In contrast, NaClO₃ is a strong oxidizer and is highly reactive, especially with combustible materials.
- Uses: NaCl is primarily used for seasoning food, as a preservative, and for de-icing roads. NaClO₃ is an industrial chemical used mainly as a powerful bleaching agent and herbicide.
8. Due to its properties, what safety precautions are important when handling Sodium Chlorate?
Handling Sodium Chlorate requires strict safety measures due to its strong oxidizing nature. Key precautions include:
- Storage: It must be stored in a cool, dry place, and kept completely separate from combustible materials like wood, cloth, organic chemicals, sulfur, and phosphorus to prevent the risk of fire or explosion.
- Handling: Wear appropriate personal protective equipment (PPE), including gloves and safety goggles, as it can be an irritant to the skin and eyes.
- Contamination: Avoid any contamination with organic materials or metals, as this can create sensitive and explosive mixtures.
- Ventilation: Always handle in a well-ventilated area to avoid inhaling any dust.
