Zinc-Carbon Dry Cell

The zinc-carbon dry cell is a common type of electrochemical cell that is used to generate electrical energy through a redox reaction. It is commonly used in household appliances such as flashlights, radios, and toys.

The zinc-carbon dry cell consists of a zinc can, which serves as the anode, surrounded by a mixture of manganese dioxide and carbon powder, which serves as the cathode. The mixture is packed around a central carbon rod, which serves as the current collector. The electrolyte is a paste of ammonium chloride and zinc chloride, which is packed inside the zinc can.

During operation, the zinc at the anode undergoes oxidation and loses electrons, which flow through the external circuit to the carbon rod and then to the cathode. At the cathode, the manganese dioxide and carbon powder mixture undergoes reduction and gains electrons. The ammonium chloride and zinc chloride electrolyte provides the ionic conductivity necessary for the redox reaction to occur.

Zinc-Carbon Dry Cell

The chemical reaction in the zinc-carbon dry cell can be represented by the following equation:

Zn(s) + 2MnO₂(s) + 2NH4Cl(aq) → ZnCl2(aq) + Mn2O₃(s) + 2NH₃(g) + H₂O(l)

The zinc-carbon dry cell has a relatively low energy density and a short lifespan compared to other types of batteries, such as alkaline and lithium-ion batteries. However, it is inexpensive and widely available, making it a popular choice for low-power applications. Additionally, the dry cell design makes it easy to handle and transport, as it does not contain a liquid electrolyte.