Question

Which metal is obtained by Self Reduction Process?

Answer 1

1. Self-reduction is the process by which the less electropositive metal cations can be reduced themselves without adding any reducing agent.
2. The metals that can be reduced by self-reduction are Mercury, Copper and Lead.
3. An example of self-reduction is when Lead Sulphide comes in contact with Oxygen Lead oxide and Sulphur dioxide is formed and Lead oxide reacts with Lead Sulphide and forms Lead and Sulphur dioxide.
   $$\begin{gathered} 2\mathrm{PbS}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{PbO}\left(\mathrm{s}\right)+2{\mathrm{SO}}_2\left(\mathrm{g}\right) \\ \mathrm{Lead}\mathrm{sulphide}\mathrm{Lead}\mathrm{monoxide} \\ 2\mathrm{PbS}\left(\mathrm{s}\right)+2\mathrm{PbO}\left(\mathrm{s}\right)\to 3\mathrm{Pb}\left(\mathrm{s}\right)+{\mathrm{SO}}_2\left(\mathrm{g}\right)\mathrm{Self}\mathrm{reduction}. \end{gathered}$$
4. Similarly, Copper and Mercury can be reduced by Self reduction.
5. The chemical equation for self-reduction of Copper is

$$\begin{gathered} {\mathrm{Cu}}_2\mathrm{S}\left(\mathrm{s}\right)+2{\mathrm{Cu}}_2\mathrm{O}\left(\mathrm{s}\right)\to 6\mathrm{Cu}\left(\mathrm{s}\right)+{\mathrm{SO}}_2\left(\mathrm{g}\right) \\ \mathrm{Copper}\mathrm{sulphide}\mathrm{Copper}\mathrm{oxide} \end{gathered}$$