Question

\( E^\circ \) value of a Daniell cell \( \text{Zn} | \text{Zn}^{2+} \, (aq) || \text{Cu}^{2+} \, (aq) | \text{Cu} \) is ............ V. (rounded off to 2 decimals)

Hint:

The standard cell potential is the difference between the reduction potential at the cathode and the anode. Use the standard values from the table to calculate \( E^\circ_{\text{cell}} \).

Answer 1

Step 1: Using the Nernst equation for calculating cell potential. The cell potential \( E^\circ \) is calculated using the standard electrode potentials for the half-reactions: \[ E^\circ_{\text{cell}} = E^\circ_{\text{cathode}} - E^\circ_{\text{anode}} \] For the Daniell cell:
- The reduction half-reaction at the cathode (copper): \[ \text{Cu}^{2+} + 2e^- \to \text{Cu} \quad E^\circ_{\text{Cu}} = +0.34 \, \text{V} \] - The oxidation half-reaction at the anode (zinc): \[ \text{Zn} \to \text{Zn}^{2+} + 2e^- \quad E^\circ_{\text{Zn}} = -0.76 \, \text{V} \] Step 2: Calculating the standard cell potential. \[ E^\circ_{\text{cell}} = 0.34 - (-0.76) = 0.34 + 0.76 = 1.10 \, \text{V} \] Final Answer: \[ \boxed{1.10 \, \text{V}} \]