A dry cell consists of a moist paste of NH4Cl and ZnCl2 contained in a Zn casing which encloses a Carbon rod surrounded by black MnO2 paste. What is the role of ZnCl2 in it?
1
It prevents pressure being developed in the cell due to NH3 gas formation.
2
It serves as cathode thus permitting Carbon rod to act as anode.
3
It acts as the anode while Carbon rod acts as the cathode.
4
It keeps the contents dry and prevents leakage of electrolyte.