Understanding the Properties and Uses of Glacial Acetic Acid by CAS Number

Understanding Glacial Acetic Acid Properties, Uses, and Safety

Glacial acetic acid, often referred to by its Chemical Abstracts Service (CAS) number 64-19-7, is a colorless, viscous liquid with a distinct sour vinegar-like smell. It is an important chemical compound widely used in various applications, particularly in the production of chemical intermediates, food preservation, and as a solvent. This article explores the properties, uses, and safety considerations associated with glacial acetic acid.

Properties of Glacial Acetic Acid

Glacial acetic acid is simply the pure form of acetic acid, containing no water. It is characterized by its high boiling point of approximately 118 °C (244 °F) and a melting point of 16.6 °C (61.9 °F). At room temperature, it appears as a clear, colorless liquid that can solidify into a crystalline form when cooled below its melting point. Due to its high purity, glacial acetic acid has a high acidity level, making it a powerful acid that can easily dissociate in water to release hydrogen ions.

In addition to its chemical properties, glacial acetic acid is hygroscopic, meaning it can absorb moisture from the air. It is miscible with water, ethanol, and ether, allowing it to mix easily with other solvents and compounds. These properties make it an essential substance in various chemical reactions and processes.

Glacial acetic acid has a wide range of industrial applications. The most significant use is in the production of acetic anhydride, which is then employed in the manufacture of cellulose acetate, an important material used in fibers, plastics, and photographic films. Additionally, glacial acetic acid serves as a precursor for the synthesis of various chemicals, including acetate esters, which are critical in the production of solvents and inks.

In the food industry, acetic acid is used as a food preservative and flavoring agent. It can be found in vinegar products, which naturally contain about 4-8% acetic acid. Due to its antimicrobial properties, acetic acid helps inhibit the growth of harmful bacteria and extends the shelf life of food products. Its distinctive taste also enhances the flavor of various dishes, making it a staple in culinary applications worldwide.

In the healthcare sector, glacial acetic acid is employed in the synthesis of pharmaceuticals and as a reagent in biochemical assays. It is involved in the production of aspirin and other medicinal compounds. Moreover, it is sometimes used for diagnostic purposes, such as in the Pap test, where it helps identify abnormal cells in cervical screenings.

Safety Considerations

While glacial acetic acid is widely used and beneficial, it is important to handle it with care due to its corrosive nature. Direct contact with skin or eyes can cause severe burns, and inhalation of its vapors may irritate the respiratory tract. Therefore, appropriate safety measures should be taken, including wearing gloves, goggles, and using it in well-ventilated areas.

In case of spills, it is crucial to neutralize the acid using a suitable alkaline material, such as sodium bicarbonate, and to contain the spill to prevent environmental contamination. In the event of accidental exposure, it is recommended to wash the affected area with copious amounts of water and seek medical attention if necessary.

When storing glacial acetic acid, it should be kept in a cool, dry place and away from incompatible materials such as strong bases, oxidizing agents, and reactive metals. Proper labeling and adherence to safety data sheets (SDS) are vital for ensuring safe handling and storage.

Conclusion

Glacial acetic acid, with its CAS number 64-19-7, is a critical compound across various industries, from chemical manufacturing to food preservation and healthcare. Its unique properties allow it to serve diverse functions, yet it must be managed safely to minimize risks associated with its corrosive nature. As its applications continue to expand, understanding glacial acetic acid's significance and safety measures will remain essential for its effective use in modern society.