The passage of electricity in the Daniell cell when Zn and Cu electrodes are connected can be explained as follows:

Introduction to the Daniell Cell:
The Daniell cell is a type of electrochemical cell that generates electricity through a redox reaction. It consists of two half-cells, one containing a zinc electrode (Zn) and the other a copper electrode (Cu), which are immersed in separate electrolyte solutions.

Redox Reaction:
When the Daniell cell is connected, a redox (reduction-oxidation) reaction takes place. In the zinc half-cell, zinc atoms oxidize and lose electrons, forming Zn2+ ions. This oxidation reaction can be represented as follows:

Zn(s) → Zn2+(aq) + 2e-

In the copper half-cell, copper ions (Cu2+) from the copper sulfate solution gain electrons and are reduced to copper atoms, which deposit onto the copper electrode. This reduction reaction can be represented as:

Cu2+(aq) + 2e- → Cu(s)

Electron Flow:
The oxidation reaction at the zinc electrode releases electrons, which flow through the external circuit towards the copper electrode. This movement of electrons constitutes an electric current.

Ion Flow:
Simultaneously, in order to balance the charges, Zn2+ ions migrate from the zinc sulfate solution to the copper sulfate solution through the salt bridge or porous separator. This ion flow maintains electrical neutrality in both half-cells.

Overall Cell Reaction:
The overall reaction of the Daniell cell can be obtained by combining the oxidation and reduction reactions:

Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)

This reaction shows the transfer of zinc ions from the zinc electrode to the copper electrode, while copper ions from the copper sulfate solution are reduced and deposited onto the copper electrode.

Electrode Potential:
The passage of electricity in the Daniell cell is driven by the difference in electrode potentials between the zinc and copper electrodes. Zinc has a higher tendency to lose electrons compared to copper, resulting in a potential difference between the two electrodes. This potential difference is responsible for the flow of electrons and the generation of electricity.

Conclusion:
In summary, when the Zn and Cu electrodes of the Daniell cell are connected, the oxidation of zinc at the zinc electrode and the reduction of copper ions at the copper electrode occur. The flow of electrons through the external circuit and the migration of ions through the salt bridge enable the passage of electricity in the cell. The overall cell reaction and the difference in electrode potentials drive this electrochemical process.

electrochemical cell