The geometry and the number of the unpaired electron(s) of ${\left[{\mathrm{MnBr}}_4\right]}^{2-}$, respectively, are

1.  Tetrahedral and 1

2.  Square planar and 1

3.   Tetrahedral and 5

4.  Square planar and 5 

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

2.335 g of compound X (empirical formal ${\mathrm{CoH}}_{12}{\mathrm{N}}_4{\mathrm{Cl}}_3$) upon treatment with excess ${\mathrm{AgNO}}_3$ solution produces 1.435 g of a white precipitate. The primary and secondary valences of cobalt in compound X, respectively are

[Given Atomic mass: Co = 59, Cl = 35.5, Ag = 108]

1.  3, 6

2.  3,  4

3.  2,  4

4.  4, 3

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

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