CFSE (in the octahedral field) will be maximum in:
(Atomic number Co = 27)

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

2. ${\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]}^{3+}$

3. ${\left[\mathrm{Co}{\left(\mathrm{CN}\right)}_6\right]}^{3-}$

4. ${\left[\mathrm{Co}{\left({\mathrm{C}}_2{\mathrm{O}}_4\right)}_3\right]}^{3-}$

The compound that gives a pair of enantiomorphs is:
(en = NH₂ CH₂CH₂ NH₂)

1. $\left[Co\right(N{H}_3{)}_{4}C{l}_2]N{O}_2$

2. $\left[Cr\right(N{H}_3{)}_6\left]\right[Co\left(CN{)}_6\right]$

3. $\left[Co\right(en{)}_{2}C{l}_2]Cl$

4. $\left[Pt\right(N{H}_3{)}_4\left]\right[PtC{l}_6]$

Copper sulphate dissolves in excess of KCN to give:

1. CuCN

2. $\left[Cu\right(CN{)}_4{]}^{3-}$

3. $\left[Cu\right(CN{)}_4{]}^{2-}$

4. $Cu(CN{)}_2$

A pair that contains both the ions coloured in an aqueous solution is:

(At. no. : Sc = 21, Ti = 22, Ni = 28, Cu = 29, Co = 27)

[Co(NH₃)₄(NO₂)₂]Cl exhibits:

[Cr(H₂O)₆]Cl₃ (At. No. of Cr = 24) has a magnetic moment of 3.83 BM. 
​​​​The correct distribution of 3d electrons in the chromium of the complex is:

1. $3d_{x^2-y^2}^1,\hspace{0.17em}3d_{z^2}^1,\hspace{0.17em}3d_{xy}^1$

2. $3d_{xy}^1,\hspace{0.17em}3d_{x^2-y^2}^1,\hspace{0.17em}3d_{yz}^1$

3. $3d_{xy}^1,\hspace{0.17em}3d_{zy}^1,\hspace{0.17em}3d_{xz}^1$

4. $3d_{xy}^1,\hspace{0.17em}3d_{yz}^1,\hspace{0.17em}3d_{z^2}^1$

Which of the following complexes has the highest paramagnetic behaviour?

(where gly = glycine, en = ethylenediamine, ox = oxalate ion and bpy = bipyridyl moieties )
(At no : Ti= 22, V = 23, Fe = 26, Co = 27)

1. [V(gly)₂(OH)₂(NH₃)₂]⁺

2. [Fe(en)(bpy)(NH₃)₂]²⁺

3.  [Co(ox)₂(OH)₂]^-

4. [Ti(NH₃)₆]³⁺

Out of ${\mathrm{TiF}}_6^{2-}$, ${\mathrm{CoF}}_6^{3-}$, Cu₂Cl₂ and ${\mathrm{NiCl}}_4^{2-}$(Z of Ti = 22, Co=27, Cu = 29, Ni= 28) the colourless species are:

1. $Ti{F}_6^{2-}$ $and$ $Co{F}_6^{3-}$

2. $C{u}_{2}C{l}_2$ $and$ $NiC{l}_4^{2-}$

3. $Ti{F}_6^{2-}$ $and$ $C{u}_{2}C{l}_2$

4. $Co{F}_6^{3-}$ $and$ $NiC{l}_4^{2-}$

A complex  ion among the following can absorb visible light is:
(At. no. Zn = 30, Sc = 21, Ti = 22, Cr = 24)

1. [Sc(H₂O)₃(NH₃)₃]³⁺

2. [Ti(en)₂ (NH₃)₂]⁴⁺

3. [Cr(NH₃)₆]³⁺

4. [Zn(NH₃)₆]²⁺

Which of the following ions doesn't exhibit optical isomerism?

(en = ethylenediamine)

1. [Co(en)₂Cl₂]⁺

2. [Co(NH₃)₃Cl₃]

3. [Co(en)Cl₂(NH₃)₂]⁺

4. [Co(en)₃]³⁺