Question

Consider the following statements:

      (A) Cr²⁺ is easier to oxidize than V²⁺ in the

            gas phase.

      (B) Cr²⁺(aq) is a more powerful reducing

            agent than V²⁺(aq).

      (C) The rate of water exchange for Cr²⁺(aq) is

            much faster than V²⁺(aq).

       Correct answer is

       1. A and B                   2. A and C

       3. B and C                   4. A,B and C

Answer 1

The outer electron configuration of V(3d3 4s2) and Cr(3d5 4s2) after oxidation V2+(3d3) and Cr2+(3d5), Cr2+ requires less energy to oxidise.So A is correct

All metals with higher negative potentials are stronger reducing agents than the metals with lower negative potentials or positive potentials.

Electrode potential of V2+(-1.18V) is more negative than Cr2+(-0.90V) ( Reference is Electrode potential chart). So the option B is incorrect.

The water exchange rate of Cr2+(1.2*10^8 s^-1) is higher than the V2+. So the option C is correct.