Description

You might not recognize its name, but phosphoric acid is likely a part of your everyday life. Often found in its concentrated form as 85% phosphoric acid, this chemical plays a surprisingly diverse role, from food and beverages to industrial processes. While it’s not something you’d want to handle casually, understanding its properties and uses can shed light on its importance.

What is Phosphoric Acid?

Phosphoric acid (H₃PO₄) is an inorganic acid derived from phosphorus. The 85% designation refers to its concentration, meaning that 85% of the solution by weight is pure phosphoric acid, with the remaining 15% being water. At this concentration, it appears as a clear, colorless, and viscous liquid. It’s a moderately strong acid, meaning it can donate hydrogen ions (H⁺) in chemical reactions, but it’s not as corrosive as some other acids like hydrochloric acid.

Key Properties of 85% Phosphoric Acid:

Viscosity: The 85% concentration gives it a syrupy consistency, making it less volatile and easier to handle compared to more dilute solutions.
Acidity: While not a super-strong acid, it’s still capable of reacting with metals and bases.
Water Solubility: It’s readily soluble in water, which is crucial for its various applications.
Non-Volatile: It doesn’t easily evaporate at room temperature, reducing the risk of inhalation hazards.
Beyond Soda: The Diverse Uses of 85% Phosphoric Acid

You might first think of phosphoric acid as the characteristic tang in cola and other carbonated drinks. However, its applications reach far beyond beverages:

Food Industry:
Acidulant: As mentioned, it’s a common acidulant in soft drinks, providing that sharp, tart flavor.
Preservative: It helps to inhibit the growth of microorganisms, extending the shelf life of certain foods.
Buffering Agent: It helps to maintain the pH of food products, ensuring consistent texture and flavor.
Ingredient in Baking Powder: It’s used in some baking powders as a leavening agent.
Fertilizer Production: Phosphoric acid is a critical component in the production of phosphate fertilizers, which are essential for agriculture and plant growth.
Industrial Cleaning: It’s an effective cleaner and rust remover, often found in industrial strength cleaning products, descalers and metal treatments.
Metal Treatment: It’s used to convert rust into a protective phosphate coating, preventing further corrosion, also known as phosphatizing or phosphating.
Dental Care: Phosphoric acid is used in dental etching, a process that prepares teeth for bonding with fillings and other dental materials.
Laboratories: It’s a valuable reagent in scientific research and chemical analysis.
Water Treatment: It’s used in some water treatment processes to control pH and prevent scale formation.
Safety Considerations:

While it’s used in many applications, 85% phosphoric acid is a corrosive substance and should be handled with caution.

Skin and Eye Irritation: Contact with skin and eyes can cause burns. Proper personal protective equipment, including gloves and goggles, should always be used.
Inhalation: Although non-volatile, concentrated forms of phosphoric acid can cause respiratory irritation. Work in well-ventilated spaces to avoid breathing in fumes.
Ingestion: Ingestion can cause severe internal damage and should be avoided.
Storage: Store in a designated, cool, and dry place, away from incompatible materials and out of reach of children.
Conclusion

Phosphoric acid 85% is a powerful and versatile chemical with a wide range of applications, impacting everything from the food we consume to the tools we use. Its acidic properties and stability make it invaluable in numerous industrial and commercial processes. While it’s essential to handle it with care due to its corrosive nature, its contributions to modern life are undeniable. Understanding its properties and uses highlights the importance of chemistry in shaping our daily world.