Question

Match the following:

Column - I		Column - II
A	$s p^{3}$	i	$CoNH _{36}{ }^{3+}$
B	$dsp^{2}$	ii	$NiCO _{4}$
C	$sp ^{3} d ^{2}$	iii	$PtNH _{32} Cl _{2}$
D	$d ^{2} sp ^{3}$	iv	$CoF _{6}^{3-}$

• A. A- i ,B- ii ,C- iv ,D- iii
• B. A- i ,B-iii ,C- iv ,D-ii
• C. A- ii ,B-iii ,C- i ,D-iv
• D. A- ii ,B-iii ,C- iv,D- i

Answer 1

Answer: (D)

I. $\left[ Co \left( NH _{3}\right)_{6}\right]^{3+}$
Here $Co$ is present as $Co ^{3+}$ ion. $NH _{3}$ being strong field ligand pair up the unpaired
electrons of $Co.$
${ }_{27} Co =\operatorname{Ar}^{7} d ^{7} 4 s ^{2}$
$\therefore Co ^{3+}= Ar ^{3} d ^{6} 4 s ^{0}$

II. $NiCO _{4}$
Here $Ni$ is present in its ground state. $CO$ being a strong field ligand, pair up the unpaired electrons of $Ni$
${ }_{28} Ni =\text{Ar} 3 d ^{8} 4 s ^{2}$

III. $PtNH _{32} Cl _{2}$
Here $Pt$ is present as $Pt ^{2+}$ ion.
${ }_{78} Pt = Xe 5 d ^{9} 6 s ^{1}$
$ Pt ^{2+}= Xe 5 d ^{8} 6 s ^{0}$

IV. $CoF _{6}^{3-}$
Here $Co$ is present as $Co ^{3+}$ ion, $F$ being weak field ligand is unable to pair up its unpaired electrons.
$Co ^{3+}=[ Ar ] 3 d ^{6} 4 s ^{0}$