Question

What is meant by corrosion?

Answer 1

1. The slow damage caused to metal due to the effect of air, water, or any chemical reaction is called corrosion.
2. For example - Silver when exposed to air reacts with Hydrogen sulfide gas present in the atmosphere.
   $$\begin{gathered} 2\mathrm{Ag}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{S}\left(\mathrm{g}\right)\to {\mathrm{Ag}}_2\mathrm{S}\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \mathrm{Silver}\mathrm{Hydrogen}\mathrm{sulfide}\mathrm{Silver}\mathrm{sulfide} \end{gathered}$$
   ${\mathrm{H}}_2\mathrm{S}$ gas is produced in various manufacturing industries and released into the atmosphere without treatment.
3. Silver undergoes decoloration and becomes black in color.