sesquioxide

sesquioxide

A chemist carefully weighs a sample of sesquioxide powder.

Definition
  1. Noun (Chemistry):
    • A chemical compound in which the ratio of the element to oxygen is two to three, forming the general formula ( \text{M}2\text{O}3 ), where M represents a metal or other element. The prefix "sesqui-" means one and a half, indicating that three oxygen atoms are combined with two atoms of the other element.
Usage Examples
Advanced Usage
  • "Sesquioxide formation": the process by which a metal reacts with oxygen to produce a compound with a 2:3 metal-to-oxygen ratio.

    • The sesquioxide formation of chromium occurs when chromium metal is heated in the presence of excess oxygen.
  • "Rare earth sesquioxides": a class of sesquioxides formed by lanthanide elements, such as lanthanum sesquioxide (La₂O₃), used in optics and electronics.

    • Neodymium sesquioxide is employed in glassmaking to create laser rods.
Variants and Related Words
  • Sesqui-: a prefix meaning "one and a half" or "three to two," used in chemical nomenclature.

    • The prefix sesqui- appears in other terms like "sesquisulfide" (M₂S₃).
  • Dioxide (n): a compound with two oxygen atoms per molecule (e.g., carbon dioxide, CO₂).

    • Unlike a dioxide, a sesquioxide contains three oxygen atoms for every two atoms of another element.
  • Trioxide (n): a compound with three oxygen atoms per molecule (e.g., sulfur trioxide, SO₃).

    • A trioxide differs from a sesquioxide in that it often involves a single atom of the other element.
Synonyms
  • M₂O₃ compound: a formal chemical designation for any substance fitting the sesquioxide formula.
  • Hemioxide (rare): an older term for a compound with half the oxygen content of a dioxide, though this is not standard.
Phrasal Verbs
  • (No common phrasal verbs exist for "sesquioxide" as it is a technical noun.)
Related Idioms
  • (No idioms are associated with "sesquioxide" due to its specialized scientific nature.)