Question
What is a mercury cell? Give the electrode reactions?
Solution
A mercury battery (also called mercuric oxide battery, or mercury cell) is a non-rechargeable electrochemical battery, a primary cell. Mercurybatteries use a reaction between mercuric oxide and zinc electrodes in an alkaline electrolyte.
Mercury cell is a new type of dry cell. It consists of
Anode: Zinc-mercury.
Cathode: Paste of HgO and carbon
Electrolyte: Paste of ZnO in KOH.
The reactions are:
Anode:
Zn (amalgam) +
At cathode:
Overall reaction: