pentahydrate

pentahydrate

A chemist carefully weighs a sample of copper sulfate pentahydrate.

Definition

Noun (Chemistry): A "pentahydrate" is a chemical compound that contains five molecules of water of crystallization per molecule of the substance. It is a type of hydrate where the water molecules are chemically bonded within the crystal structure.

Usage Examples
  • (A compound with five water molecules attached to copper sulfate.)
  • (The chemical notation indicating five water molecules per formula unit.)
Advanced Usage
  • "Anhydrous vs. pentahydrate": The pentahydrate form of a compound often differs in color, solubility, and stability from its anhydrous (water-free) form.

    • When heated, the blue copper sulfate pentahydrate loses its water and turns into a white anhydrous powder. (The removal of water molecules changes the appearance.)
  • "Pentahydrate in industrial applications": Many pentahydrates are used in agriculture or manufacturing due to their specific hydration properties.

    • Magnesium sulfate pentahydrate is used as a fertilizer to provide essential nutrients to crops. (The hydrated form aids in nutrient delivery.)
Variants and Related Words
  • Hydrate (n): a compound containing water molecules bonded within its crystal structure.

    • A hydrate can have one or more water molecules; a pentahydrate has exactly five.
  • Anhydrous (adj): describing a compound without water of crystallization.

    • The anhydrous form of the salt is more reactive than the pentahydrate.
  • Pentahydrated (adj): containing five water molecules (less common, synonymous with pentahydrate).

    • The pentahydrated crystal structure is stable at room temperature.
Synonyms
  • Five-water hydrate: a descriptive term for a compound with five water molecules.
    • Chemists often refer to pentahydrate as a five-water hydrate for clarity.
Related Idioms
  • "Water of crystallization": the water molecules that are part of the crystal structure of a hydrate.
    • In a pentahydrate, the water of crystallization accounts for a specific percentage of the total mass. (The water is chemically bound, not simply absorbed.)