COMEDK20269 May 2026Morning ShiftChemistryElectrochemistryActual
Consider a Galvanic cell in which the following reactions occurs: Fe ²⁺(aq) + Ag ^+(aq) Fe ³⁺(aq) + Ag (s) . What is the standard potential of the cell? Given: E^0_ ( Ag ^+/ Ag ) = aV , E^0_ ( Fe ²⁺/ Fe ) = bV & E^0_ ( Fe ³⁺/ Fe ) = cV
Options
- A(a + b + 2c) ,V
- B(a + 2b - 3c) ,V
- C(a - 2c + b) ,V
- D(a + c - 2b) ,V
Correct answer
B. (a + 2b - 3c) ,V
Step-by-step solution
The given cell reaction is Fe ²⁺(aq) + Ag ^+(aq) Fe ³⁺(aq) + Ag (s) . The standard cell potential is given by: E^0_ cell = E^0_ cathode - E^0_ anode = E^0_ Ag ^+/ Ag - E^0_ Fe ³⁺/ Fe ²⁺ We are given: E^0_ Ag ^+/ Ag = a E^0_ Fe ²⁺/ Fe = b E^0_ Fe ³⁺/ Fe = c To find E^0_ Fe ³⁺/ Fe ²⁺ , we use the relation G^0 = -nFE^0 . For the half-reaction Fe ³⁺ + 3e^- Fe , G^0₁ = -3Fc For the half-reaction Fe ²⁺ + 2e^- Fe , G^0₂ = -2Fb The desired half-reaction is obtained by subtracting the second reaction from the first: Fe ³⁺ +