MHT CET202522 Apr 2025Evening ShiftChemistryElectrochemistryActual
If E ^ ( Fe _ ( aq ) ⁺² Fe _ ( s ) )=-0.44 ~V and E ^ ( Sn _ ( aq ) ⁺² Sn _ ( s ) )=-0 14 ~V . What is standard emf of cell containing the two electrodes?
Options
- A+0.30 ~V
- B-0.30 ~V
- C+0.58 ~V
- D-0.58 ~V
Correct answer
A. +0.30 ~V
Step-by-step solution
The standard cell EMF is determined from the standard reduction potentials. Tin has the higher (less negative) reduction potential at -0.14 V , so it serves as the cathode where reduction occurs: Sn ²⁺_ ( aq ) + 2e^- Sn _ ( s ) . Iron has the lower (more negative) reduction potential at -0.44 V , so it serves as the anode where oxidation occurs: Fe _ ( s ) Fe ²⁺_ ( aq ) + 2e^- . The standard cell potential is calculated as E^ _ cell = E^ _ cathode - E^ _ anode = (-0.14 V ) - (-0.44 V ) = +0.30 V . Alternatively, us