![Q.48 E 0 value of a Daniell cell Zn|Zn2+ (aq)||Cu2+ (aq)|Cu is ___________V. (rounded off to 2 decimals) [E0 Zn 2+|Zn = - 0.76 V; E0 Cu 2+|Cu = + 0.34 V]](https://www.letstalkacademy.com/wp-content/uploads/2025/12/slide_48-2.jpg)
Q.48
E 0 value of a Daniell cell Zn|Zn2+ (aq)||Cu2+ (aq)|Cu is ___________V. (rounded off to 2
decimals)
[E0 Zn 2+|Zn = – 0.76 V; E0 Cu 2+|Cu = + 0.34 V]
Daniell Cell E0 Value: Zn|Zn2+||Cu2+|Cu is 1.10 V (Calculation Explained)
The standard cell potential (E0) for the Daniell cell Zn|Zn2+ (aq)||Cu2+ (aq)|Cu is 1.10 V, calculated from the given reduction potentials E0 Zn2+|Zn = -0.76 V and E0 Cu2+|Cu = +0.34 V.
Cell Reaction
Zinc acts as the anode where oxidation occurs: Zn(s) → Zn2+(aq) + 2e-. Copper serves as the cathode for reduction: Cu2+(aq) + 2e- → Cu(s). The overall reaction is Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s), driving spontaneous electron flow from zinc to copper.
E0 Calculation
E0 cell = E0 cathode – E0 anode = E0 Cu2+|Cu – E0 Zn2+|Zn = 0.34 V – (-0.76 V) = 1.10 V. This positive value confirms the cell is galvanic and produces electrical energy under standard conditions.
Option Analysis
| Option | Explanation | Status |
|---|---|---|
| 1.10 V | Matches the subtraction of reduction potentials, standard for Daniell cells. | Correct |
| -1.10 V | Reverses anode-cathode roles, yielding negative E0 for a non-spontaneous setup. | Incorrect |
| 0.42 V | Possible addition error (0.76 + 0.34 = 1.10, not subtraction). | Incorrect |
| -0.42 V | Incorrect reversal and operation on potentials. | Incorrect |
| 0.00 V | Implies equilibrium, but potentials differ significantly. | Incorrect |
