Which of the following reactions will not occur under standard conditions? Given E° values: Fe³⁺/Fe²⁺ = +0.77 V, I₂/I⁻ = +0.54 V.
Correct: B
A spontaneous reaction requires E°cell > 0. For Fe³⁺ + I⁻: E°cell = 0.77 - 0.54 = +0.23 V (spontaneous). For Br⁻/Br₂: E°cell = 0.77 - 1.07 = -0.30 V (non-spontaneous). Option C is invalid because Cl⁻ reduction to Cl₂ has E°=1.36 V, making E°cell negative.