Question

If the emf of cell, \(\text{Cu}_{(s)}|\text{Cu}_{(1M)}^{2+}|\text{Ag}_{(1M)}^+|\text{Ag}\) is 0.463 V at \(25 ^{\circ}\text{C}\) and standard potential of Cu electrode is 0.337 V. Find the standard potential of Ag electrode

• A. \(0.128 \text{V}\)
• B. \(-0.128 \text{V}\)
• C. \(0.8 \text{V}\)
• D. \(-0.8 \text{V}\)

Hint:

At 1 M both ions, \(E_{cell} = E^{\circ}_{cathode} - E^{\circ}_{anode}\).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
The cell is Cu | Cu\(^{2+}\) (1 M) || Ag\(^+\) (1 M) | Ag. Copper is the anode (oxidation) and silver is the cathode (reduction).

Step 2: Key Formula or Approach
Both concentrations are 1 M, so the cell is at standard conditions:
\[ E_{cell} = E^{\circ}_{Ag} - E^{\circ}_{Cu} \]

Step 3: Detailed Explanation
\[ 0.463 = E^{\circ}_{Ag} - 0.337 \]
\[ E^{\circ}_{Ag} = 0.463 + 0.337 = 0.800\ \text{V} \]
A negative value cannot come out, because the cell emf is positive and silver is above copper in the series.

Final Answer:
The standard potential of the silver electrode is 0.8 V, option (C). \[ \boxed{0.8\ \text{V (C)}} \]