The voltage of a copper-zinc galvanic cell is 1.10 V.
This specific voltage is generated due to the difference in the electrochemical potentials of copper and zinc when they are combined to form a galvanic cell. This type of cell converts chemical energy into electrical energy through spontaneous redox reactions.
Understanding the Cell Voltage
To determine the voltage of a copper-zinc galvanic cell, the individual standard electrode potentials of each metal are taken into account. These potentials indicate the tendency of a species to be reduced.
| Metal | Standard Electrode Potential |
|---|---|
| Copper | +0.34 V |
| Zinc | -0.76 V |
In a galvanic cell consisting of copper and zinc:
- Zinc (Zn), with a more negative (or less positive) potential, acts as the anode, where oxidation occurs (it loses electrons).
- Copper (Cu), with a more positive potential, acts as the cathode, where reduction occurs (it gains electrons).
The overall cell voltage, or electromotive force (EMF), is calculated by subtracting the anode potential from the cathode potential:
Cell Voltage (E_cell) = E_cathode - E_anode
Applying the values:
E_cell = (+0.34 V) - (-0.76 V)
E_cell = 0.34 V + 0.76 V
E_cell = 1.10 V
Operation of the Cell
In an open circuit configuration, where no current is flowing, a voltmeter placed across the electrodes measures this potential difference of 1.10 V. Each electrode effectively maintains its potential relative to its local electrolyte. When the circuit is closed, a current begins to flow, enabling the chemical reactions to proceed and deliver electrical power.
