What are the applications of redox reactions in industry?

Redox reactions are widely used in industries for processes like metal extraction, energy production, and manufacturing of various products.

Redox reactions, short for reduction-oxidation reactions, play a crucial role in numerous industrial processes. One of the most common applications is in the extraction of metals. For instance, in the extraction of iron from its ore, a redox reaction is used to reduce iron oxide to iron. The iron oxide is heated with carbon, where carbon acts as a reducing agent and gets oxidised to carbon dioxide, while iron oxide gets reduced to iron.

Another significant application of redox reactions is in the production of energy. In batteries and fuel cells, redox reactions are used to generate electricity. For example, in a typical alkaline battery, a redox reaction occurs between zinc and manganese dioxide, producing electricity. Similarly, in fuel cells, a redox reaction between hydrogen and oxygen produces electricity, with water as a by-product.

Redox reactions are also used in the manufacturing of various products such as bleach, fertilisers, and plastics. In the production of bleach, chlorine is oxidised to hypochlorite ion, a powerful bleaching agent. In the production of fertilisers, ammonia is oxidised to nitrate, a key nutrient for plants. In the production of plastics, redox reactions are used in the polymerisation process, where small molecules are combined to form large molecules.

In the field of water treatment, redox reactions are used to remove pollutants. For example, in the process of chlorination, chlorine is added to water to oxidise and kill harmful bacteria and other microorganisms. Similarly, in the process of ozonation, ozone is used to oxidise and remove organic and inorganic substances from water.

IGCSE Chemistry Tutor Summary: Redox reactions are essential in industries for metal extraction, energy production, making products like bleach, fertilisers, and plastics, and for water treatment. These reactions, where substances gain or lose electrons, help in converting raw materials into useful products, generating electricity in batteries and fuel cells, and cleaning water by removing pollutants and harmful organisms.