In which of the following reactions, the underlined substance has been oxidised?

Options

A. `Br_(2)+H_(2)S to underline(2HBr)+S`
B. `underline(2HgCl_(2))+SnCl_(2)tounderline(Hg_(2)Cl_(2))+SnCl_(4)`
C. `Cl_(2)+underline(2Kl)to2KCl+underline(l_(2))`
D. `underline(2Cu^(2+))+4l^(-)tounderset(Cu_(2)l_(2))+l_(2)`

Answer

D

Explanation

Oxidation is the addition of electronegative element or removal of electropositive element or increase in oxidation number.
`Cl_(2)+underline(2Kl)to 2KCl+ underline (l_(2))`
In this reaction, the underlined species is oxidised as it involves the removal of electropositive element, i.e., `K^(+)`
However, in the option (d) on the basis of applied concept, `Cu^(2+)` seems to undergo oxidation but in actual, `Cu^(2+)` is undergoing reduction and reduces to `Cu^(+)`. thus, in the reaction,