Local action in an electrochemical action can be prevented by

Options

A. using by pure electrolytes in tw half cells
B. using very pure metal for anode
C. coating zinc anode with mercury
D. using pure graphite for cathode.

Answer

B,C

Explanation

Local action leads to the eating away of the metal used as anode in an electrochemical cell. It is due to the presence of impurities in the metal used for making anode. These impurities help in setting up of tiny electrochemical reaction cells on the surface of anode which results in the eating away of the metal . it can be prevented by using very pure metals for anode or by coaing the zinc anode with mercury.