Question

Distinguish between combustion and rusting on the basis of rate , nature of the reaction and residue.

Answer 1

Dear student,

Rusting occurs on the surface of substances, while combustion is with the whole substance.
Rusting is a surface phenomenon whereas combustion is a bulk phenomenon.
Rusting is a very slow process than combustion. Hence, the rate of rusting is very slow, and that of combustion is very fast.
Rusting takes place only in the presence of water and oxygen whereas only oxygen is necessary for the combustion process.
Both rusting and combustion reactions are exothermic in nature.
Brown to the red-colored residue (iron oxide) is formed after rusting and grey to the black color residue (ash) is generated after combustion.

Regards