Question

which of the following pair of metals are extracted by self reduction from its main ore but metals don't evolve with ​

Answer 1

Mercury (Hg), Lead (Pb), Copper (Cu)

Explanation:

Self-reduction is also known as the auto reduction process or air reduction process. The sulphide ores of less electropositive metals like Mercury (Hg), Lead (Pb), Copper (Cu), etc. are heated in the air, so a part of the oxide ore converts into sulphate. This will then react with the remaining sulphide ore to yield the metal and sulphur dioxide gas. No external reducing agent is used in this process.