Statement I: Ecell must have a positive value for a galvanic cell to work.
Statement II: In a working galvanic cell, Ecathode < Eanode.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Statement I is correct but Statement II is false
The cell potential is the difference between the electrode (reduction) potentials of the cathode and the anode. With the anode on the left and the cathode on the right:
\( \displaystyle E_{\text{cell}}=E_{\text{right}}-E_{\text{left}}=E_{\text{cathode}}-E_{\text{anode}} \)
Statement I: Ecell must have a positive value for a galvanic cell to work. — True. A galvanic cell converts the chemical energy of a spontaneous redox reaction into electrical energy, and for such a cell the emf, Ecathode − Eanode, is positive. A zero or negative value means no spontaneous reaction, and the cell gives no current.
Statement II: In a working galvanic cell, Ecathode < Eanode. — False. If Ecathode were less than Eanode, Ecell would be negative and the cell would not work. In a working cell reduction takes place at the electrode with the higher reduction potential, so Ecathode > Eanode.
NCERT (2026-27 edition):
2.2 Galvanic Cells – “As mentioned earlier a galvanic cell is an electrochemical cell that converts the chemical energy of a spontaneous redox reaction into electrical energy. … The potential difference between the two electrodes of a galvanic cell is called the cell potential and is measured in volts. The cell potential is the difference between the electrode potentials (reduction potentials) of the cathode and anode. … It is now an accepted convention that we keep the anode on the left and the cathode on the right while representing the galvanic cell. … Under this convention the emf of the cell is positive and is given by the potential of the half-cell on the right hand side minus the potential of the half-cell on the left hand side i.e.,”
\( \displaystyle E_{\text{cell}}=E_{\text{right}}-E_{\text{left}} \)