Which among the following is most paramagnetic?

Step-by-step solution

Paramagnetic character is based upon the presence of unpaired electrons in d -subshell. In these complex ions. (a) In [ Cr ( H ₂ O )₆ ]³⁺ , Cr is present as Cr ³⁺( Oxidation number =+3) Cr ³⁺=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^3 (b) In [ Fe ( H ₂ O )₆ ]²⁺, Fe is present as Fe ²⁺=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^6 (c) In [ Cu ( H ₂ O )₆ ]²⁺, Cu is present as Cu ²⁺ Cu ²⁺=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^9 (d) In [ Zn ( H ₂ O )₂ ]²⁺, Zn is present as Zn ²⁺=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d¹⁰ In complex (a), (b) and (