Question

Which of the following sulphide when heated strongly in air gives the corresponding metal without undergoing separate reduction of oxide?

• A. $Cu_{2}S$
• B. FeS
• C. HgS
• D. ZnS

Answer 1

Answer: (C)

HgS

Answer 2

When heated in air HgS is converted into oxide which decomposes to give metal and oxygen

$2HgS + 3O_{2} \rightarrow 2HgO + 2SO_{2}$

$2HgO \rightarrow 2Hg + O_{2}$