$$\begin{gathered} \mathrm{Among} \left(\mathrm{i}\right) {\left[\mathrm{Cr}{\left(\mathrm{en}\right)}_3\right]}^{3+}, \left(\mathrm{ii}\right) \mathrm{trans}-{\left[\mathrm{Cr}{\left(\mathrm{en}\right)}_2{\mathrm{Cl}}_2\right]}^{+}, \\ \left(\mathrm{iii}\right) \mathrm{cis}-{\left[\mathrm{Cr}{\left(\mathrm{en}\right)}_2{\mathrm{Cl}}_2\right]}^{+}, \left(\mathrm{iv}\right) {\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_4\mathrm{Cl}\right]}^{+}, \mathrm{the} \mathrm{optically} \mathrm{active} \\ \mathrm{complexes} \mathrm{are} \end{gathered}$$

1.  (i) and (ii)

2.  (i) and (iii)

3.  (ii) and (iii)

4.  (ii) and (iv)

Among the following complexes, the one that can exist as facial (fac) and meridional (mer) isomers is

1.  $\left[\mathrm{Co}{\left({\mathrm{NO}}_2\right)}_3{\left({\mathrm{NH}}_3\right)}_3\right]$

2.  ${\mathrm{K}}_3\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]$

3.  $\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_2{\left({\mathrm{NH}}_3\right)}_4\right]{\mathrm{CI}}_3$

4.  $\left[\mathrm{CoCl}{\left({\mathrm{NH}}_3\right)}_5\right]\mathrm{CI}$  

Hybridization and geometry of ${\left[\mathrm{Ni}{\left(\mathrm{CN}\right)}_4\right]}^{2-}$ are

1.  $s{p}^{2}d$ and tetrahedral

2.  $s{p}^3$ and square planar

3.  $s{p}^3$ and tetrahedral

4.  $ds{p}^2$ and square planar

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 IUPAC name of $\left[\mathrm{Co}\left(\mathrm{ONO}\right){\left({\mathrm{NH}}_3\right)}_5\right]{\mathrm{Cl}}_2$ is:

1. Pentamminenitro-O-cobalt(II)chloride

2. Pentamminenitroso-O-cobalt(III)chloride  

3. Pentaamminenitrito-O-cobalt(III) chloride

4. Pentammineoxo-nitrocobalt(III)chloride

The metal carbonyl which is paramagnetic is

1. $\mathrm{Ni}{\left(\mathrm{CO}\right)}_4$

2. $\mathrm{V}{\left(\mathrm{CO}\right)}_6$

3. $\mathrm{Cr}{\left(\mathrm{CO}\right)}_6$

4. $\mathrm{Fe}{\left(\mathrm{CO}\right)}_5$

Which one of the following reactions is correct?

1.  $\left[\mathrm{Fe}\right(\mathrm{CO}{)}_5]+2\mathrm{NO}\to \left[\mathrm{Fe}\right(\mathrm{CO}{)}_2\left(\mathrm{NO}{)}_2\right]+3\mathrm{CO}$

2.  $\left[\mathrm{Fe}\right(\mathrm{CO}{)}_5]+2\mathrm{NO}\to \left[\mathrm{Fe}\right(\mathrm{CO}{)}_3\left(\mathrm{NO}{)}_2\right]+2\mathrm{CO}$

3.  $\left[\mathrm{Fe}\right(\mathrm{CO}{)}_5]+3\mathrm{NO}\to \left[\mathrm{Fe}\right(\mathrm{CO}{)}_2\left(\mathrm{NO}{)}_3\right]+3\mathrm{CO}$

4. $\left[\mathrm{Fe}\right(\mathrm{CO}{)}_5]+3\mathrm{NO}\to \left[\mathrm{Fe}\right(\mathrm{CO}{)}_3\left(\mathrm{NO}{)}_3\right]+2\mathrm{CO}$

How many isomers are possible for complex $\left[\mathrm{Co}{\left(\mathrm{ox}\right)}_2{\mathrm{Cl}}_2\right]+?$

1.  1

2.  3

3.  2

4.  4