Question

Explain Daniel cell with cell diagram representation and process taking place in the cell.

Answer 1

Daniel Cell

• Daniel cell is an electrochemical device that can convert chemical energy to electrical energy.
• In an electrochemical cell, the anode is negative and the cathode is positive.
• Electrons flow from anode to cathode.
• In the daniel cell, Anode is made of Zinc$\left(\mathrm{Zn}\right)$ metal dipped in Zinc salt solution i.e., Zinc sulphate$\left({\mathrm{ZnSO}}_4\right)$and the Cathode is made of Copper$\left(\mathrm{Cu}\right)$ metal dipped in the copper salt solution i.e., Copper sulphate$\left({\mathrm{CuSO}}_4\right)$.

Cell Diagram

• At the anode, oxidation takes place.
• $\mathrm{Zn}\left(\mathrm{s}\right)\to {\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}$
• At the cathode, reduction takes place
• ${\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\to \mathrm{Cu}\left(\mathrm{s}\right)$
• Overall, cell reaction is
• $\mathrm{Zn}\left(\mathrm{s}\right)+{\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)\to {\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right)+\mathrm{Cu}\left(\mathrm{s}\right)$
• Cell representation
• $\mathrm{Zn}\left(\mathrm{s}\right)|{\mathrm{Zn}}^{2+}(\mathrm{aq})||{\mathrm{Cu}}^{2+}(\mathrm{aq})|\mathrm{Cu}\left(\mathrm{s}\right)$
• Here, the Left part is oxidation half cell and the right part is reduction half cell.
• The double vertical lines ( || ) represent the salt bridge.

Working principle

• The oxidation of Zinc metal at the anode produces $2$electrons.
• The electrons move from anode to cathode through a metal wire that connects the electrodes.
• The free flow of electrons produces electricity.
• The electricity is produced opposite to the flow of electrons i.e., cathode to anode.
• The salt bridge completes the circuit.

Application

• It is used to produce electricity.
• It is also used to store electricity.
• It is used in Battery development.