Describe briefly the method to obtain mercury from Cinnabar. Write the chemical equations for the reactions involved in the process.

Explanation

When cinnabar (HgS) is heated in the presence of air, it is first converted into mercuric oxide.
`2Hg(S) + underset("(air)")(3O_(2))overset("Heat")rarr 2HgO + SO_(2)`
Mercuric oxide is then reduced to mercury on further heating.
`2HgO overset("Heat")rarr 2Hg + O_(2)`