Which of the fo llowing reaction is possible at anode?

Options

A. `2Cr^(3+)+ 7H_(2)Oto Cr_(2)O_(7)^(2-) +14H^(+)`
B. `F_(2) to 2F^(-)`
C. `(1//2) O_(2)+ 2H^(+) to H_(2)O`
D. None of these

Answer

A

Explanation

`2Cr^(3+) +7H_(2)OtoCr_(2)O_(7)^(2-) +14H^(+)`
O.S. of Cr changes from +3 to +6 by loss of electrons. At anode oxidation takes place.