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Q.
Which will reduce zinc oxide to zinc?
AMUAMU 2004
Solution:
Magnesium is placed above zinc in electrochemical series ie, its reduction potential is less than zinc so, it is more electropositive than zinc and it is also better reducing agent then zinc therefore, Mg will reduce zinc oxide to zinc.
$Mg + ZnO \longrightarrow Zn + MgO$
While the reduction potential of $Pb,\, Cu$ and $Fe$ are higher than $Zn$ so, they cannot reduce zinc oxide to zinc.
The substances which have lower reduction potentials are stronger reducing agents while those which have higher reduction potentials are stronger oxidising agents.