MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

The standard emf of a cell is given by E^ _ cell = E^ _ cathode - E^ _ anode . To obtain the maximum standard emf, the cathode must have the highest standard reduction potential and the anode must have the lowest standard reduction potential. Given standard reduction potentials are: E^ _ A = +2.5 V E^ _ B = +3.0 V E^ _ C = -2.0 V E^ _ D = -1.5 V The highest reduction potential is for electrode B (+3.0 V ), so B should act as the cathode. The lowest reduction potential is for electrode C (-2.0 V ), so C should act as the anode. Maximum E^ _ cell = 3.0 - (-2.0) = 5.0 V . Thus, 'C' is the anode and 'B' is the cathode. Answer: 'C' is anode and 'B' is cathode