Question

Explain how mercury is extracted from its sulphide ore cinnabar. Give chemical equations of
the reactions involved.


CBSE Class X Science SA 1 ( 2 marks)

Answer 1

When cinnabar,a ore of mercury, is heated in air, it is first oxidised and converted into mercuric oxide (HgO).

Mercuric oxide on further heating  is then reduced to mercury .

The following are the equations which take place.

2HgS(s) + 3O2(g) -Heat → 2HgO(s) + 2SO2(g) ..2HgO(s) Heat → 2Hg(l) + O2(g).

Answer 2

Answer: mercury is first roosted the continued to heat  

Explanation: As Mercury is  a low but reactive metal it is found in the form of sulphide ore / oxide ore

so extraction is done by providing heat in presence of oxygen (Rosting)

then it becomes oxide ore we just need to provide heat and we get Hg

Equation:

1) HgS + O2 → HgO + SO2

2) HgO + Heat → Hg + O2