Chemistry - Coordination Chemistry Question with Solution | TestHub

* (P) $[Cr(H_{2}O{)}_{4}B{r}_2{]}^{+}:$$C{r}^{3+}$ ($d^3$) has 3 unpaired electrons, making it paramagnetic (1). It undergoes $d^{2}s{p}^3$ hybridization (3) and exhibits cis/trans geometrical isomerism (2) $\to$ (1, 2, 3).

* (Q) $[Co(en{)}_2(CN{)}_2{]}^{+}:$ Contains the symmetrical bidentate ligand 'en' (5) and ambidentate $C{N}^{-}$ which shows linkage isomerism (4). $C{o}^{3+}$ ($d^6$, low-spin) forms a $d^{2}s{p}^3$ complex (3) and shows geometrical isomerism (2) $\to$ (2, 3, 4, 5).

* (R) $[Pt(ox{)}_2{]}^{2-}:$ Being a $d^8$ square planar complex, its central atom is $ds{p}^2$ hybridized (not $d^{2}s{p}^3$). It contains oxalate ($o{x}^{2-}$), which is a symmetrical bidentate ligand (5) $\to$ (5).

* (S) $[Fe(OH{)}_4{]}^{-}:$$F{e}^{3+}$ ($d^5$) with a weak-field ligand is a high-spin tetrahedral complex containing 5 unpaired electrons, making it paramagnetic (1) $\to$ (1).