Question

Can the process of rusting be called combustion. Discuss.

Answer 1

Hint: Rusting is an Oxidation Process and mainly associated with Iron. Rust forms when iron is exposed to water or moisture for a prolonged period. All the iron substances are prone to rusting and can cause the substance to disintegrate completely.

Complete answer:
The chemical formula for rust is $F{e_2}{O_3}$ . Rust is also known as Iron (III) Oxide. Iron reacts with water/moisture to form hydrated Iron (III) Oxide, which we call as rust. The rust formed on the surface of the iron doesn’t allow the iron below its surface to get exposed to the moisture and oxygen.
The process of burning, scientifically, is known as combustion. Combustion is the process of burning of any substance in presence of oxygen from the air. This process transfers heat and light to the surrounding. Combustion is the process responsible for formation of oxides.
The process of rusting cannot be considered to combustion because:
The process of combustion produces energy in the form of heat and light. No energy is produced in the process of rusting. In combustion substances react with oxygen to form Oxides, Heat and light, whereas in rusting iron reacts with moisture and oxygen to form Iron (III) Oxide only. The pace of the rusting process is very slow as compared to combustion which is spontaneous and exothermic. Combustion occurs at a higher temperature known as the ignition temperature whereas rusting occurs at room temperature only. The process of combustion is an exothermic redox reaction, whereas rusting is just an oxidation reaction with loss of electrons and gain of oxygen.

Note:
The process of rusting is prevented by using the process of Galvanization. In this, the iron substance is plated or coated with Zinc. This layer of zinc prevents the iron from getting exposed to oxygen and moisture, thereby preventing rusting.