Primary cells become dead after some time; as electrode reactions cannot be reversed, i.e., redox reaction takes place only once hence non-rechargeable.
Dry cell, mercury cell
Dry cell :
It is a compact form of Lechlanche cell. In brief it can be summarised as:
Anode Zinc Container
Cathode Graphite rod surrounded by and carbon .
Electrolyte Apaste of filled between two electrodes.
Cell Potential 1.25 to 1.5 Volt
Relation: At anode
Here combine to give complex ion .
This cell has a very short life duration and cell may get corroded even when it is not in use as being acidic corrode Zn-container.
Here reducing agent is Zn(Hg), i.e., anode while oxidising agent, i.e., cathode is graphite. Electrolyte is
Cell potential is 1.35 volt and it does not change during life time since, no ion is involved in the reaction whose concentration may change.
It is used in hearing aids and watches.
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