Which of the following reaction is possible at anode ?

Options

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

Answer

A

Explanation

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