Consider the following reduction processes :
$Al^{3 +} + 3 e^{-} ⟶ Al (s), E^{0} = - 1.66 V Fe^{3 +} + e^{-} ⟶ Fe^{2 +}, E^{0} = + 0.77 V Co^{3 +} + e^{-} ⟶ Co^{2 +}, E^{0} = + 1.81 V Cr^{3 +} + 3 e^{-} ⟶ Cr (s), E^{\circ} = - 0.74 V$ The tendency to act as reducing agent decreases in the order :

Question

Consider the following reduction processes :

Al^{3 +} + 3 e^{-} ⟶ Al (s), E^{0} = - 1.66 V Fe^{3 +} + e^{-} ⟶ Fe^{2 +}, E^{0} = + 0.77 V Co^{3 +} + e^{-} ⟶ Co^{2 +}, E^{0} = + 1.81 V Cr^{3 +} + 3 e^{-} ⟶ Cr (s), E^{\circ} = - 0.74 V

The tendency to act as reducing agent decreases in the order :

Accepted Answer

Correct answer: A. (a) Reducing agent strength is determined by oxidation potential (opposite sign of reduction potential). Stronger reducing agents have more negative oxidation potentials (easier to oxidize). Oxidation potentials: Al (s ) Al^3^+has E^ =+1.66 V (strongest reducing agent); Cr (s ) Cr^3^+has E^ =+0.74 V; Fe^2^+ Fe^3^+has E^ =-0.77 V; Co^2+ Co^3+ has E^ =-1.81 V (weakest reducing agent). Order of decreasing reducing agent tendency: Al> Cr> Fe^2+> Co^2+.

Solution

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