Electrode potential data are given below:
Fe+3 (aq) + e− → Fe+2 (aq); E∘ = +0.77V
Al3+ (aq) + 3e− → Al (s); E∘ = −1.66V
Br2 (aq) + 2e− → 2Br− (aq); E∘ = +1.08V
Based on the data, the reducing power of Fe2+, Al and Br− will increase in the order
1
Br− < Fe2+ < Al
2
Fe2+ < Al < Br−
3
Al < Br− < Fe2+
4
Al < Fe2+ < Br