Chemistry - Coordination Chemistry Question with Solution | TestHub

A. In $[NiC{l}_4{]}^{2-}$, Ni is in +2 oxidation state ($d^8$). Cl⁻ is a weak field ligand, so it's high spin, tetrahedral. Unpaired electrons = 2. In O₂, there are 2 unpaired electrons (paramagnetic). Total = $2+2=4$. (Correct)

B. $[Ni(en{)}_2(N{H}_3{)}_2{]}^{2+}$ has 3 stereoisomers (cis-trans and cis-enantiomers). $[Zn(Gly{)}_2]$ has 2 stereoisomers (cis-trans). Total = $3+2=5$, not 7. (Incorrect)

C. $PtC{l}_4\cdot 2N{H}_3$ is a neutral complex, $Pt(N{H}_3{)}_{2}C{l}_4$, giving 0 ions. $CoC{l}_3\cdot 3N{H}_3$ is also a neutral complex, $Co(N{H}_3{)}_{3}C{l}_3$, giving 0 ions. The number of ions is the same (zero). (Incorrect)

D. In $[Ni(CO{)}_4]$, Ni is in 0 oxidation state, $3d^{10}4s^0$. Valence electrons = 10. In $[Fe(CO{)}_4{]}^{2-}$, Fe is in -2 oxidation state, $3d^{10}4s^0$. Valence electrons = 10. The number of valence electrons is the same. (Correct)