The formula of copper(II) oxide is:

  1. CuO
  2. Cu2O
  3. CuO
  4. Cu2O2


Copper is present in +2 oxidation state.

The correct answer is: CuO

    • When a metal can have multiple oxidation states, the particular oxidation state in which it exists in that compound in mentioned in binary in the bracket.
    • In the formula in binary the oxidation state of the metal is mentioned.
    • The copper is present in +2 oxidation state and the oxide is present in -2. Each copper and oxygen is present in one unit each.
    • The chemical formula of copper(II) oxide is CuO.