Question

Among the following complex compounds–${\mathrm{K}}_3[\mathrm{Fe}(\mathrm{CN}{)}_6]$$(i)$$\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$(ii) ${\mathrm{K}}_2[\mathrm{Pt}(\mathrm{CN}{)}_4]$$(\mathrm{iii})$$\left[\mathrm{Zn}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]{\left({\mathrm{NO}}_3\right)}_2$$(iv)$diamagnetic complexes are –

• (A) (i), (ii) and (iii)
• (B) (ii) and (iii)
• (C) (i) and (iv)
• (D) (ii), (iii) and (iv)

Answer 1

The Correct Option is D

Explanation:
${\mathrm{K}}_3[\mathrm{Fe}(\mathrm{CN}{)}_6]$${\mathrm{Fe}}^{+3}$ has $3{\mathrm{d}}^5$ configuration, ${\mathrm{CN}}^{-}$ is strong field ligand and thus ${\mathrm{Fe}}^{+3}$ has four electron paired leaving one unpaired electron with ${\mathrm{d}}^2{\mathrm{sp}}^3$ hybridization and thus paramagnetic.(ii) $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$${\mathrm{Co}}^{3+}$ has $3{\mathrm{d}}^6$ configuration, ${\mathrm{NH}}_3$ is strong field ligands thus all six electrons are paired with ${\mathrm{d}}^2{\mathrm{sp}}^3$ hybridization and therefore diamagnetic.(iii) ${\mathrm{K}}_2[\mathrm{Pt}(\mathrm{CN}{)}_4]$${\mathrm{Pt}}^{+2}$ has $3{\mathrm{d}}^8$ configuration, ${\mathrm{CN}}^{-}$ is strong field ligand and thus all the eight electrons are paired with ${\mathrm{dsp}}^2$ hybridization and therefore diamagnetic.(iv) $\left[\mathrm{Zn}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]{\left({\mathrm{NO}}_3\right)}_2$${\mathrm{Zn}}^{+2}$ has $3{\mathrm{d}}^{10}$ configuration and thus all paired, showing ${\mathrm{sp}}^3{\mathrm{d}}^2$ hybridization and so diamagnetic.