The complex that can exhibit optical activity among the following is:

1. [CoCl₆]^3-

2. [Co(en)CI₄]^-

3. cis-[Co(en)₂Cl₂]⁺

4. trans-[Co(en)₂Cl₂]⁺ 

2.335 g of compound X (empirical formal CoH₁₂N₄Cl₃) upon treatment with excess AgNO₃ 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]

The geometry and magnetic property of ${\left[{\mathrm{NiCl}}_4\right]}^{2-}$, respectively, are

1.  Tetrahedral, Paramagnetic

2.  Tetrahedral, Diamagnetic

3.  Square planar, Paramagnetic

4.  Square planar, Diamagnetic  

Among
(i) [Cr(en)₃]³⁺
(ii) trans-[Cr(en)₂Cl₂]⁺
(iii) cis-[Cr(en)₂Cl₂]⁺
(iv) [Co(NH₃)₄Cl₂]⁺
the optically active complexes are-

1. (i), (ii) and (iii)

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) isomer is:

The total number of geometrical isomers possible for an octahedral complex of $\left[{\mathrm{MA}}_2{\mathrm{B}}_2{\mathrm{C}}_2\right]$ are:
(M = transition metal; A, B and C are monodentate ligands)

The IUPAC name of [Co(ONO)(NH₃)₅]Cl₂ is: 

1.  Pentamminenitrocobalt(II)chloride

2.  Pentamminenitrsoocobalt(III)chloride  

3. Pentaaminenitrito-O-cobalt(III)chloride.  

4. Pentammineoxo-nitrocobalt(III)chloride

The metal carbonyl which is paramagnetic is:

1. NO₃^- acts as a monodentate ligand.
2. The Ce atom has a coordination number of 12.
3. The shape of the complex ion is an icosahedron.
4. The solution is used as an oxidizing agent.