Definition

1. Noun:
   • A strong, corrosive acid: Hydroiodic acid is a chemical compound, specifically a strong acid formed when hydrogen iodide gas dissolves in water.
   • Aqueous hydrogen iodide: It is the aqueous solution of the diatomic molecule hydrogen iodide (HI).

Usage Examples

• Noun:
  • Hydroiodic acid is commonly used as a reducing agent in organic chemistry.
  • The laboratory stored the hydroiodic acid in a dark glass bottle to prevent decomposition by light.

Advanced Usage

• In chemical synthesis: Hydroiodic acid is frequently employed to cleave ethers into alkyl iodides and alcohols, a reaction known as cleavage with HI.
  • The methyl ether was converted to iodomethane using hot, concentrated hydroiodic acid.
• As a catalyst: It can serve as a catalyst in certain organic reactions due to its strong acidic nature and ability to provide iodide ions.
  • The reaction proceeded efficiently with hydroiodic acid as the catalyst.

Variants and Related Words

• Hydrogen iodide (HI): The gaseous compound that, when dissolved in water, forms hydroiodic acid. These terms are often used interchangeably, though strictly, "hydrogen iodide" refers to the gas and "hydroiodic acid" to the aqueous solution.
• Hydriodic acid: An older, alternative spelling for hydroiodic acid.

Synonyms

• Aqueous HI: A descriptive synonym emphasizing its composition.
• Hydriodic acid: (Variant spelling)

Notes on Meaning

• Chemical Context: The term "hydroiodic acid" is almost exclusively used in scientific and industrial contexts, particularly in chemistry and chemical engineering. It is not used in everyday language.
• Concentration: The strength and properties of the acid depend on its concentration in water. Commercial solutions are typically around 55-57% HI by weight.

Noun

1. an acid formed by aqueous solution of hydrogen iodide