Question

Name the ore of mercury. With the help of balanced chemical equations, explain the process of extraction of mercury from its ore.

Answer 1

The ore of mercury is cinnabar (HgS).

The extraction of mercury from cinnabar ore involves two steps. 

1. The concentrated mercury (II) sulphide ore is roasted in the air to form mercuric oxide (HgO).
2. This mercuric oxide formed is then reduced to mercury on further heating to about 300°C.
   \[\ce{2HgS_{(s)} + 3O2_{(g)} ->[\Delta] 2HgO_{(s)} + 2SO2_{(g)}}\]
   \[\ce{2HgO_{(s)} ->[\Delta] 2Hg_{(l)} + O2_{(g)}}\]