NEET2026ChemistryElectrochemistryActual
The standard electrode potential ( E^ ) for the half-cell reaction Fe ³⁺+e^- Fe ²⁺ at 298 K is (Given: E^ ( Fe ³⁺/ Fe )=-0.04 V and E^ ( Fe ²⁺/ Fe )=-0.44 V at 298 K)
Options
- A+0.92 V
- B+0.40 V
- C+0.76 V
- D-0.48 V
Correct answer
C. +0.76 V
Step-by-step solution
The given half-cell reactions are: Fe ³⁺ + 3e^- Fe , E^ ₁ = -0.04 V G^ ₁ = -n₁FE^ ₁ = -3 F (-0.04) = 0.12F Fe ²⁺ + 2e^- Fe , E^ ₂ = -0.44 V G^ ₂ = -n₂FE^ ₂ = -2 F (-0.44) = 0.88F The required half-cell reaction is: Fe ³⁺ + e^- Fe ²⁺ This reaction can be obtained by subtracting the second reaction from the first reaction: G^ ₃ = G^ ₁ - G^ ₂ -1 F E^ ₃ = 0.12F - 0.88F -FE^ ₃ = -0.76F E^ ₃ = +0.76 V Answer: +0.76 V