Which of the following complexes has a spin-only magnetic moment of 2.83 BM and also exhibits geometrical isomerism?

Step-by-step solution

A spin-only magnetic moment of 2.83 BM corresponds to n(n+2) = 2.83 , which gives n=2 unpaired electrons. Let us evaluate the options: [ Pt ( NH ₃)₂ Cl ₂ ] : Pt(II) is a 5d⁸ system. It forms a square planar complex ( n=0 , = 0 BM). It exhibits geometrical isomerism (cis and trans forms), but the magnetic moment is incorrect. [ Ni ( NH ₃)₅ Cl ]⁺ : Ni(II) is a 3d⁸ system in an octahedral field. It has n=2 unpaired electrons ( = 2.83 BM). However, it is an MA ₅ B type complex, which does not show geometrical isomerism