Which of the following reactions canot be a base for electrochemical cell?

Options

A. `H_(2)+O_(2)toH_(2)O`
B. `AgNO_(3)+ZntoZn(NO_(3))_(2)+Ag`
C. `2Cr+3FeSO_(4)toCr_(2)(SO_(4))_(3)+3Fe`
D. `KMnO_(4)+FeSO_(4)+H_(2)SO_(4)toK_(2)SO_(4)+Fe_(2)(SO_(4))_(3)+MnSO_(4)+H_(2)O`

Answer

D

Explanation

Electrochemical cell are based upon the redox reaction. The reaction given in option d does not involve redox reactio. So it cannot be a base for electrochemical cell.