Question

Match the following:

Column I		Column II
A	$sp^3$	i	(i) $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$
B	$dsp^2$	ii	$[Ni(CO)_4]$
C	$sp^3d^2$	iii	(iii) $\left[\mathrm{Pt}\left(\mathrm{NH}_3\right)_2 \mathrm{Cl}_2\right]$
D	$d^2sp^3$	iv	$[CoF_6]^{3−}$

• A. $A -(v), B -(ii), C -(iv), D-(iii)$
• B. $A -(ii), B -(iii), C -(iv), D-(v)$
• C. $A -(ii), B -(iii), C -(i), D-(v)$
• D. $A -(ii), B -(iii), C -(iv), D-(i)$

Answer 1

Answer: (D)

I. $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

Here $\text{Co}$ is present as $\text{Co}^{\text{3+}}$ ion. $\text{NH}_{\text{3}}$ being strong field ligand pair up the unpaired electrons of $\text{Co}$ .

$_{\text{27}} \text{Co} \, \text{=} \, \left[\text{Ar}\right] \text{3d}^{\text{7}} \text{4s}^{\text{2}}$

$\therefore \, \text{Co}^{\text{3+}} \, \text{=} \, \left[\text{Ar}\right] \text{3d}^{\text{6}} \text{4s}^{\text{0}}$



II. $\left[\text{Ni} \left(\text{CO}\right)_{\text{4}}\right]$

Here $\text{Ni}$ is present in its ground state. $\text{CO}$ being a strong field ligand, pair up the unpaired electrons of $\text{Ni}$

$_{\text{28}} \text{Ni} \, \text{=} \, \left[\text{Ar}\right] \text{3d}^{\text{8}} \text{4s}^{\text{2}}$



III. $\left[\text{Pt} \left(\left(\text{NH}\right)_{\text{3}}\right)_{\text{2}} \left(\text{Cl}\right)_{\text{2}}\right]$

Here $\text{Pt}$ is present as $\text{Pt}^{\text{2+}}$ ion.

$_{\text{78}} \text{Pt} \, \text{=} \, \left[\text{Xe}\right] \text{ 5d}^{\text{9}} \text{6s}^{\text{1}}$

$\text{Pt}^{\text{2+}} \text{=} \, \left[\text{Xe}\right] \text{ 5d}^{\text{8}} \text{6s}^{\text{0}} \, $



IV. $\left[\text{CoF}_{\text{6}}\right]^{\text{3} -}$

Here $\text{Co}$ is present as $\text{Co}^{\text{3+}}$ ion, $\text{F}$ being weak field ligand is unable to pair up its unpaired electrons.

$\text{Co}^{\text{3+}} \, \text{=} \, \text{[Ar]} \, \text{3d}^{\text{6}} \text{4s}^{\text{0}}$