Q. Among the following metals the number of metals that are extracted by self-reduction method from their respective ores is

Hg, Zn, Cu, Al, Mg, Pb, Fe, Na.

 1905  206 NTA AbhyasNTA Abhyas 2020General Principles and Processes of Isolation of Elements Report Error

Answer: 3

Solution:

Self-Reduction Process: The cations of the less electropositive metals like Pb, Hg and Cu may be reduced without the use of any additional reducing agent.

Self-reduction of Cu:



It is called self-reducing because copper oxide itself reduced the copper sulfide to give copper and sulfur dioxide.

Similar reactions occurs for Pb and Hg.