Working Principle of Mercury Cell
The mercury cell is a kind of primary cell that cannot be recharged or reused; rather, it generates current through irreversible chemical reactions in the electric cell.
The zinc compound functions as the anode in a mercury cell, where an oxidation reaction happens, while the mercury compound serves as the cathode, where a reduction reaction occurs. An electrolyte that ionizes in a molten state to conduct electricity is either potassium hydroxide or sodium hydroxide.
Electrochemical Reactions in Mercury Cell
The cathode of a mercury cell can consist of either pure mercury(II) oxide (HgO) or a combination of manganese dioxide and mercuric oxide. Some graphite are combined with magnesium oxide (MgO), which is a non-conductor of electricity.
Half-cell reaction at the cathode:
HgO(s) + H2O+ 2e¯ → Hg(l) + 2OH¯
The standard potential during the reduction reaction is +0.0977 V.
Half-cell reaction at the anode:
Zn(Hg) + 2OH¯→ ZnO(s) + H2O+ 2e¯
The overall reaction for the mercury cell:
Zn + HgO(s) → ZnO(s) + Hg(l)
Mercury Cell
Mercury Cell is a type of Primary Cell, which is non-rechargeable in nature, meaning it can only be used once before discarding it. The Mercury Cell is generally a small button-like structure and is mainly used in low-current devices such as watches, BIOS batteries on motherboards, and pacemakers. The Mercury cell has a potential of 1.35 Volts and is made by filling chemicals like mercury, mercuric oxide, carbon powder, zinc oxide, etc., into a steel container the size of a button.
In this article, we will learn about the mercury cell and its components and working of mercury cells and different types of mercury cells, and the advantages and applications of mercury cells.
Table of Content
- What is Mercury Cell?
- Construction of Mercury Cells
- Working Principle of Mercury Cell
- Different Types of Mercury Cell
- Mercury Cell Vs Dry Cell
- Applications of Mercury Cell