Definition

Noun: 1. A weak, poisonous, liquid acid: A corrosive, aqueous solution of hydrogen fluoride (HF). It is characterized as a weak acid compared to strong mineral acids but is highly toxic and dangerously corrosive to human tissue and glass.

Usage

• As a chemical reagent: Hydrofluoric acid is used in industrial processes, such as glass etching, semiconductor manufacturing, and petroleum refining.
• Describing properties: It is specifically noted for its unique ability to dissolve silica and silicate materials like glass.
• Warning context: Due to its extreme hazard, it is almost always discussed with caution regarding its handling, storage, and health effects.

Examples

• General Use:
  • Workers must wear specialized protective equipment when handling hydrofluoric acid.
  • The laboratory uses hydrofluoric acid to etch patterns onto silicon wafers.
  • Unlike other acids, hydrofluoric acid requires specific medical treatment for exposure.
• Defining Property:
  • Hydrofluoric acid is stored in plastic containers because it attacks glass.

Advanced Usage

• Technical Context: In chemistry, its weakness as an acid (partial dissociation in water) is contrasted with its intense chemical reactivity and toxicity, which arise from the fluoride ion's ability to bind strongly to calcium and silicon.
  • Despite being a weak acid, hydrofluoric acid causes severe systemic toxicity by binding to calcium in the blood.

Variants and Related Words

• Hydrogen fluoride (HF) (n): The gaseous compound that, when dissolved in water, forms hydrofluoric acid. Often used interchangeably in industrial contexts but technically refers to the pure compound.
• Fluoride (n): The anion (F⁻) present in hydrofluoric acid and its salts.
• Etchant (n): A substance used to etch; hydrofluoric acid is a common etchant for glass and silicon.

Synonyms

• HF(aq): The standard chemical abbreviation for an aqueous solution of hydrogen fluoride (hydrofluoric acid).
• Fluoridic acid: A less common synonym.

Related Phrases / Collocations

• Hydrofluoric acid burn: A specific and severe type of chemical burn caused by exposure.
• Hydrofluoric acid exposure: The event or condition of coming into contact with the acid.
• Hydrofluoric acid solution: Emphasizes it is a mixture, typically specifying concentration (e.g., a 10% hydrofluoric acid solution).

Noun

1. a weak poisonous liquid acid; formed by solution of hydrogen fluoride in water