Oxidation-reduction reactions involve the simultaneous occurrence of oxidation and reduction processes. The term “redox” is derived from the words “reduction” and “oxidation,” reflecting this dual nature of the reactions.

In a redox reaction, one reactant undergoes oxidation (loses electrons or gains oxygen) while another reactant undergoes reduction (gains electrons or loses oxygen), simultaneously.

Reduction involves the gain of electrons or the loss of oxygen by a substance during a chemical reaction. This leads to a decrease in the oxidation state of the substance.

Oxidation refers to the process in which a substance gains oxygen or loses electrons during a chemical reaction. It results in an increase in the oxidation state of the substance.

The chemical equation for the formation of barium sulfate precipitate is: Ba²⁺ + SO₄²⁻ → BaSO₄. Barium ions (Ba²⁺) react with sulfate ions (SO₄²⁻) to produce insoluble barium sulfate (BaSO₄), which precipitates out of the solution.