The surface of copper powder becomes coated with black copper(II) oxide, resulting in a black coating on the copper surface.

The reaction is a double displacement reaction, where ions from the reactants exchange to form a precipitate (BaSO₄) and a soluble product (sodium chloride).

The chemical equation for the displacement reaction between iron and copper sulfate is: Fe + CuSO₄ → FeSO₄ + Cu. Iron reacts with copper sulfate to form iron sulfate and elemental copper.

Reactions that produce a precipitate can be classified as precipitation reactions. These reactions involve the formation of an insoluble solid (the precipitate) from the mixing of soluble reactants in solution.

The formation of a white, insoluble substance indicates the production of a precipitate. This precipitate is indicative of a precipitation reaction occurring, where a solid forms from the reaction of soluble reactants.