Explanation:
[tex]Cu^{2+}+Zn\rightarrow Zn^{2+}+Cu[/tex]
I) Oxidation reaction : When there is an increase in oxidation state number.
[tex]Zn\rightarrow Zn^{2+}+2e^-[/tex]
Reduction reaction : when there is a decrease in oxidation state number.
[tex]Cu^{2+}+2e^-\rightarrow Cu[/tex]
II) Zinc metal has gone under oxidation, as its oxidation state is changing from 0 to 2+. Zinc metal is getting converted into zinc ions.
III) Copper(II) ion has gone under reduction, as its oxidation state is changing from 2+ to 0. Copper ions are getting converted into copper metal.
IV) [tex]Cu^{2+}[/tex] is an oxidant.
Those chemical agents which get reduced itself and oxidize others is called oxidizing agents.
V)[tex]Zn[/tex] is an reductant.
Those chemical agents which get oxidized itself and reduce others is called reducing agents.