Question

Define redox reaction. Give one example.

Answer 1

The reactions in which oxidation and reduction reactions occur simultaneously are called redox reactions. The redox reactions are electron transfer reactions.
For example, consider the following redox reaction.
$Zn+C{u}^{2+}\to Z{n}^{2+}+Cu$
$Zn$ atom loses two electrons. Hence, it is oxidised to $Zn\left(II\right)$ ions.
$Cu\left(II\right)$ ion gain two electrons. Hence, it is reduced to $Cu$ atom.