Question

Mention two harmful/damaging effects of corrosion.

Answer 1

Corrosion:

Corrosion is the slow destruction of metal due to air or moisture resulting in corresponding oxide or hydroxide formation.

For example, rusting of iron.

$$\begin{gathered} 4\mathrm{Fe}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)+6{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 4\mathrm{Fe}{\left(\mathrm{OH}\right)}_3\left(\mathrm{s}\right) \\ \mathrm{Iron}\mathrm{oxygen}\mathrm{water}\mathrm{Iron}\left(\mathrm{III}\right)\mathrm{hydroxide} \\ \left(\mathrm{air}\right)\left(\mathrm{moisture}\right) \end{gathered}$$

Damaging effects

1. Metal loses its shine. For example, silver tarnishes.
2. Metals turn brittle. For example, iron sculptures get brittle due to the formation of iron oxide.