Question

The standard electrode potential of electrode-A and electrode-B are \(-0.25 \, \text{V}\) and \(-0.76 \, \text{V}\), respectively. If a Galvanic cell is created using these two electrodes, the standard electromotive force (EMF) of this cell will be:

• A. 0.51 V and electrode-B will act as anode
• B. 0.51 V and electrode-A will act as anode
• C. 0.51 V and electrode-B will act as anode
• D. 1.01 V and electrode-B will act as anode

Hint:

Remember, the cathode is the electrode with the higher (more positive) potential, while the anode is the electrode with the lower (more negative) potential.

Answer 1

The Correct Option is B

The standard EMF (\(E_{\text{cell}}^\circ\)) of a Galvanic cell is given by the equation: \[ E_{\text{cell}}^\circ = E^\circ_{\text{cathode}} - E^\circ_{\text{anode}}. \] In this case, the cathode will be the electrode with the more positive electrode potential, and the anode will be the electrode with the more negative electrode potential.
Given:
- \(E^\circ_{\text{A}} = -0.25 \, \text{V}\),
- \(E^\circ_{\text{B}} = -0.76 \, \text{V}\).
Thus, the anode will be electrode-B (more negative), and the cathode will be electrode-A. \[ E_{\text{cell}}^\circ = (-0.25) - (-0.76) = 0.51 \, \text{V}. \] Therefore, the standard EMF of the cell is \(0.51 \, \text{V}\), and electrode-A will act as the anode.