In aqueous solution, ${\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}$ (X) reacts with molecular oxygen in the presence of excess liquor $N{H}_3$ to give a new complex Y. The number of unpaired electrons in X and Y are, respectively

1.  3,1

2.  3,0

3.  3,3

4.  7,0 

The energies of ${\mathrm{d}}_{\mathrm{xy}} \mathrm{and} {{\mathrm{d}}_{\mathrm{z}}}^2$ orbitals in octahedral and tetrahedral transition metal complexes are such that

1.  $\mathrm{E}\left({\mathrm{d}}_{\mathrm{xy}}\right) > \mathrm{E}\left({\mathrm{d}}_{{\mathrm{z}}^2}\right)$ in both tetrahedral and octahedral complexes

2.  $\mathrm{E}\left({\mathrm{d}}_{\mathrm{xy}}\right) < \mathrm{E}\left({\mathrm{d}}_{{\mathrm{z}}^2}\right)$ in both tetrahedral and octahedral complexes

3.  $\mathrm{E}\left({\mathrm{d}}_{\mathrm{xy}}\right) > \mathrm{E}\left({\mathrm{d}}_{{\mathrm{z}}^2}\right)$ in tetrahedral but $\mathrm{E}\left({\mathrm{d}}_{\mathrm{xy}}\right) < \mathrm{E}\left({\mathrm{d}}_{{\mathrm{z}}^2}\right)$ in octahedral complexes

4.   $\mathrm{E}\left({\mathrm{d}}_{\mathrm{xy}}\right) < \mathrm{E}\left({\mathrm{d}}_{{\mathrm{z}}^2}\right)$  in tetrahedral but $\mathrm{E}\left({\mathrm{d}}_{\mathrm{xy}}\right) > \mathrm{E}\left({\mathrm{d}}_{{\mathrm{z}}^2}\right)$ in octahedral complexes   

The number of geometrical isomers of $\left[{\mathrm{CrCl}}_2\left(\mathrm{en}\right){\left({\mathrm{NH}}_3\right)}_2\right]$, where en = ethylenediamine, is

1.  2

2.  3

3.  4

4.  1

Among the following complexes, the one that can exhibit optical activity is

1.  ${\left[{\mathrm{CoCl}}_6\right]}^{3-}$

2.  ${\left[\mathrm{Co}\left(\mathrm{en}\right){\mathrm{CI}}_4\right]}^{-}$

3.  $\mathrm{cis}-{\left[\mathrm{Co}{\left(\mathrm{en}\right)}_2{\mathrm{Cl}}_2\right]}^{+}$

4.  trans-${\left[\mathrm{Co}{\left(\mathrm{en}\right)}_2{\mathrm{Cl}}_2\right]}^{+}$

The total number of geometrical isomers possible for an octahedral complex of this type $\left[{\mathrm{MA}}_2{\mathrm{B}}_2{\mathrm{C}}_2\right]$ is 

(M = transition metal; A, B and C are monodentate ligands)

1.  3

2.  4

3.  5

4.  6

The metal carbonyl which is paramagnetic is

1.  Ni ${\left(\mathrm{CO}\right)}_4$

2.  V ${\left(\mathrm{CO}\right)}_6$

3.  Cr ${\left(\mathrm{CO}\right)}_6$

4.  Fe ${\left(\mathrm{CO}\right)}_5$

The complex having zero crystal field stabilization energy is

1.  ${\left[\mathrm{Mn}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}$

2.  ${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}$

3.  ${\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}$

4.  ${\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}$

IUPAC name of complex ion ${\left[{\mathrm{CrCl}}_2{\left(\mathrm{ox}\right)}_2\right]}^{3-}$ is

1.  Dichlorodioxalatochromium (lll)

2.  Dioxalatodichloromate (lll)

3.  Dichlorodioxalatochromate (lll)

4.  Bisoxalaedichlorochromate (lll)

Which of the following complexes formed by ${\mathrm{Cu}}^{2+}$ ions is most stable?

1.  ${\mathrm{Cu}}^{2+}+4{\mathrm{NH}}_3 \rightleftharpoons {\left[\mathrm{Cu}{\left({\mathrm{NH}}_3\right)}_4\right]}^{2+}, \log \mathrm{K}=11.6$

2.  ${\mathrm{Cu}}^{2+} + 4\mathrm{CN}– \rightleftharpoons [\mathrm{Cu}{\left(\mathrm{CN}\right)}_4{]}^{2-} , \mathrm{logK} = 27.3$

3.  ${\mathrm{Cu}}^{2+} + 2\mathrm{en} \rightleftharpoons [\mathrm{Cu}{\left(\mathrm{en}\right)}_2{]}^{2+} , \mathrm{logK} = 15.4$

4.  ${\mathrm{Cu}}^{2+} + 4{\mathrm{H}}_2\mathrm{O} \rightleftharpoons [\mathrm{Cu}{\left({\mathrm{H}}_2\mathrm{O}\right)}_4{]}^{2+} , \mathrm{logK} = 8.9$

The color of the coordination compounds depends on the crystal field splitting. What will be the correct order of absorption of the wavelength of light in the visible region, for the complexes, ${\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]}^{3+}, {\left[Co{\left(CN\right)}_6\right]}^{3-}, {\left[Co{\left(H_{2}O\right)}_6\right]}^{3+}$

1.   $[\mathrm{Co}{\left(\mathrm{CN}\right)}_6{]}^{3-}$ > $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{]}^{3+}$ > $[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{3+}$

2.  $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{]}^{3+}$ > $[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{3+}$ > $[\mathrm{Co}{\left(\mathrm{CN}\right)}_6{]}^{3-}$

3.   $[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{3+}$ > $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{]}^{3+}$ > $[\mathrm{Co}{\left(\mathrm{CN}\right)}_6{]}^{3-}$

4.   $[\mathrm{Co}{\left(\mathrm{CN}\right)}_6{]}^{3-}$ > $[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{]}^{3+}$ > $[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}^{3+}$