Question

The standard electrode potential (EO) values of Al3+/AI, Ag+/Ag, K+/K and Cr3+/Cr are -1.66 V, 0.80 V, -2.93 V and -0.74 V, respectively. The correct decreasing order of reducing power of the metal is [NEET-2019 (Odisha)] (1) AI > K > Ag > Cr (2) Ag > Cr > AI > K (3) K > Al > Cr > Ag (4) K > Al > Ag > Cr​

Answer 1

Answer:

The decreasing order of the reducing power of metals is  K > Al > Cr > Ag.

Explanation:

Given that,

      E° (Al³⁺/Al) = -1.66V

     E° (Ag⁺/Ag) = 0.80V

          E° (K⁺/K) = -2.93V

     E° (Cr³⁺/Cr) = -0.74V

If the reduction potential is more negative, then the metal gets oxidized to ions easily. That means the metal has high reducing power.

The more negative the E° value, the greater will be the reducing power of metal.

Order of the reducing power :

            K > Al > Cr > Ag

Hence, correct option is (3).