A varibale opposite external potential `E_("ext")` is applied to the cell `Zn|Zn^(2+)(1M)|Cu^(2+)(1M)|Cu` of potential 1.1 V when `E_("ext") lt 1.1 V` and `E_("ext") gt 1.1 V` respecitively electrons flow from

Options

A. cathode to anode in both cases
B. cathode to anode and anode to cathode
C. anode to cathode and cathode to anode
D. anode to cathode in both cases

Answer

B

Explanation

For the daniell cell
`E_("cell") = 0.34 -(-0.76) = 1.10 V`
when `E_("ext") lt 1.10 V` electrons flow form cathode to anode in external circuit
when `E_("ext") gt 1.10 V` electron flow form cathode to anode in external circuit (reverse reaction )