Question

A metal that exists as a liquid at room temperature is obtained by heating its sulphide in the presence of air. Identify the metal and its ore and give the reactions involved.

Answer 1

1. On heating, the sulphides and oxides are reduced in the case of metals low in activity series.
2. Here, the metal liquid at room temperature is mercury.
3. Then we heat mercury sulphide ore to give mercury.
   $$\begin{gathered} 2\mathrm{HgS}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2\mathrm{HgO}\left(\mathrm{s}\right)+2{\mathrm{SO}}_2\left(\mathrm{g}\right) \\ \mathrm{Mercury}\left(\mathrm{II}\right)\mathrm{Oxygen}\mathrm{Mercury}\left(\mathrm{II}\right)\mathrm{Sulphur}\mathrm{dioxide} \\ \mathrm{sulphide}\mathrm{oxide} \end{gathered}$$
   $$\begin{gathered} 2\mathrm{HgO}\left(\mathrm{s}\right)\to 2\mathrm{Hg}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right) \\ \mathrm{Mercury}\left(\mathrm{II}\right)\mathrm{Mercury}\mathrm{Oxygen} \\ \mathrm{oxide} \end{gathered}$$

Therefore, on heating, the sulphides and oxides are reduced in the case of metals low in activity series.