Barium Oxide

Barium Oxide (BaO) / CAS NO. 1304-28-5

Barium oxide, also known as baria, is an inorganic compound with the formula BaO. It is a white to yellowish, hygroscopic solid that reacts readily with water, forming barium hydroxide (Ba(OH)₂). The CAS Number 1304-28-5 uniquely identifies this chemical in the Chemical Abstracts Service database.

Physical and Chemical Properties

• Molecular Formula: BaO
• Molecular Weight: 153.33 g/mol
• Appearance: White to yellowish solid or powder
• Melting Point: Approximately 1,923°C
• Boiling Point: 2,000°C
• Density: 5.72 g/cm³
• Solubility: Reacts with water to form barium hydroxide; insoluble in organic solvents.

Production of Barium Oxide

Barium oxide is typically produced by:

1. Thermal Decomposition: Heating barium carbonate (BaCO₃) or barium nitrate (Ba(NO₃)₂) results in the release of carbon dioxide or nitrogen oxides, leaving behind BaO. BaCO3→ΔBaO+CO2\text{BaCO}_3 \xrightarrow{\Delta} \text{BaO} + \text{CO}_2 BaCO3​Δ​BaO+CO2​
2. Reduction of Barium Sulfate: By reducing barium sulfate (BaSO₄) in a furnace, barium oxide can also be formed.

Uses of Barium Oxide

1. Glass Manufacturing

Barium oxide is a critical component in the glass industry, especially in the production of specialized glass such as optical glass. Adding barium oxide improves the refractive index, hardness, and chemical durability of the glass, making it ideal for optical lenses and precision instruments.

2. Cathode Coatings

In the electronics industry, barium oxide is used as a coating material for cathodes in vacuum tubes, cathode ray tubes (CRTs), and some display devices. Its ability to emit electrons when heated makes it valuable in these applications.

3. Catalyst

Barium oxide is used as a catalyst in certain chemical reactions. For example:

• It catalyzes the dehydration of alcohols to produce ethers.
• It is used in the production of ethylene oxide.

4. Desiccant

Due to its ability to react with water, barium oxide is used as a drying agent or desiccant in specific industrial processes. It helps remove traces of moisture from organic solvents and gases.

5. Steel and Ceramics

Barium oxide is added to steel during manufacturing to improve its physical properties. It is also used in the ceramics industry to enhance the thermal and mechanical strength of ceramic products.

6. Gas Absorber

Barium oxide is an effective getter material in vacuum systems. It helps maintain the vacuum by absorbing oxygen and other gases.

7. Fuel Additives

Barium oxide is sometimes used as an additive in fuels to improve combustion efficiency and reduce emissions.

Safety and Handling

Although barium oxide has many industrial uses, it is highly reactive and potentially hazardous. Key safety considerations include:

• Reactivity with Water: When exposed to water or moisture, barium oxide forms barium hydroxide, a caustic substance.
• Toxicity: Barium compounds can be toxic if ingested or inhaled. Exposure may lead to symptoms like respiratory irritation, gastrointestinal distress, or muscle weakness.
• Handling Precautions: Proper personal protective equipment (PPE), such as gloves, goggles, and a mask, should be used when handling barium oxide.

Environmental Considerations

Due to its toxicity, barium oxide must be disposed of carefully to prevent contamination of soil and water sources. It is regulated in various regions to minimize its environmental impact.

Conclusion

Barium oxide (CAS NO. 1304-28-5) is an essential compound with a wide range of applications in industries such as glass manufacturing, electronics, and catalysis. Its chemical and physical properties make it a versatile material, but careful handling and proper safety measures are necessary due to its reactivity and potential health risks.