Which fo the following is a redox reaction ?

Options

A. `Na_2SO_4 + BaCl_2 rarr BaSO_4 + 2NaCl`
B. ` SO_2 + H_2O rarr H_2SO_3`
C. `2 CuSO_4 + 4Kl rarr 2Cu l +2K_2SO_4`+I_2
D. ` CuSO_4 + 4NH_3 rarr [Cu(NH_3)_4]SO_4`

Answer

C

Explanation

Reaction (1) is a double displacement reaction, reaction(2) involves hydration, and reaction (4) involves the formation fo a complex compound.
Reaction (3) is a redox reaction as the oxidation number of Cu is reduced while that of `I` is increased
`3overset(+2)(C)uSO_(4)+4Koverset(-1)(I) rarr2 overset(+2)(C)uI+2K_(2)SO_(4)+overset(0)(I_(2))`