Definition

1. Noun:
   • A hydrated blue crystalline form of copper sulfate: "Blue copperas" is a specific term for the pentahydrate form of copper(II) sulfate, characterized by its bright blue color and crystalline structure. It is a chemical compound with the formula CuSO₄·5H₂O.

Usage

• The term "blue copperas" is used primarily in chemistry, mineralogy, and industrial contexts to refer to this specific hydrated salt. It is less common in everyday language, where "copper sulfate" or "blue vitriol" might be used.

Examples

• Noun:
  • The geologist identified the mineral as blue copperas.
  • We need to order more blue copperas for the laboratory experiment.
  • The bright blue color of the solution confirmed the presence of blue copperas.

Advanced Usage

• As a specific chemical reagent: Used to denote the pure, crystalline form in scientific procedures.
  • The protocol requires the use of finely ground blue copperas.

Variants and Related Words

• Copper sulfate (or sulphate): The general name for the compound CuSO₄, which can be anhydrous (white) or hydrated (blue).
• Blue vitriol: A common historical and industrial name for the same substance.
• Chalcanthite: The natural mineral form of blue copperas.

Synonyms

• Copper(II) sulfate pentahydrate: The systematic chemical name.
• Cupric sulfate pentahydrate: An alternative chemical name.

Notes

• "Blue copperas" is a compound noun where "blue" describes the color of this specific hydrated form. The word "copperas" historically referred to various sulfate salts (e.g., green copperas for iron sulfate). This entry explains the term "blue copperas" as a single, fixed lexical unit for the specific compound.

Noun

1. hydrated blue crystalline form of copper sulfate