Definition

1. Noun:
   • A specific inorganic acid: Orthophosphoric acid is a mineral (inorganic) acid with the chemical formula H₃PO₄. It is a clear, colorless, odorless, and non-volatile liquid or crystalline solid. It is the most common and important form of phosphoric acid.

Usage

• Orthophosphoric acid is primarily used as an industrial chemical.
• It is a key ingredient in the production of phosphate fertilizers, providing essential phosphorus for plant growth.
• It is used in the manufacturing of detergents and soaps as a pH adjuster and for its cleaning properties.
• It serves as a food additive (E338) for acidification and flavoring in beverages like colas.
• It is employed in laboratories and industries for rust removal, metal treatment, and as a chemical intermediate.

Examples

• Noun:
  • The purity of the orthophosphoric acid is critical for this pharmaceutical process.
  • Farmers rely on fertilizers produced from orthophosphoric acid to enrich the soil.
  • The lab technician handled the diluted orthophosphoric acid with care.

Advanced Usage

• Technical Context: In chemistry, "orthophosphoric acid" specifically denotes the parent compound H₃PO₄, distinguishing it from other phosphoric acids like metaphosphoric or pyrophosphoric acids. It is a triprotic acid, meaning it can donate three protons (H⁺ ions).
  • The titration curve shows the three distinct equivalence points characteristic of orthophosphoric acid.

Variants and Related Words

• Phosphoric Acid: Often used as a common name for orthophosphoric acid, though technically "phosphoric acid" can refer to a broader class of compounds.
• Phosphate (noun): A salt or ester of phosphoric acid, especially of orthophosphoric acid (e.g., calcium phosphate).
• Orthophosphate (noun): The anion (PO₄³⁻) or salt derived specifically from orthophosphoric acid.

Synonyms

• Phosphoric(V) acid: A systematic name used in chemical nomenclature.
• H₃PO₄: The chemical formula, used as a synonym in scientific contexts.

Related Phrases / Compounds

• Phosphate fertilizer: A major product derived from orthophosphoric acid.
• Food-grade phosphoric acid: Purified orthophosphoric acid suitable for use in food and beverages.

Noun

1. an acid used in fertilizers and soaps: H3PO4