In which of the following coordination entities the magnitude of \(\Delta_{oct}\)(CFSE in the octahedral field) will be maximum? 
(Atomic number Co = 27)

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

2. [Co(NH₃)₆]³⁺

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

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

Which of the following will give a pair of enantiomorphs? 
(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. $\left[Pt\right(N{H}_3{)}_4\left]\right[PtC{l}_6]$

[Co(NH₃)₄(NO₂)₂]Cl exhibits :

1. Linkage isomerism, ionization isomerism and optical isomerism

2. Linkage isomerism, ionization isomerism and geometrical isomerism

3. Ionization isomerism,geometrical isomerism and optical isomerism

4. Linkage isomerism, geometrical isomerism and optical isomerism

What is the correct electronic configuration of the central atom in ${\mathrm{K}}_4\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\right]$ based on crystal field theory?

1.  ${\mathrm{e}}^4$ ${\mathrm{t}}_2^2$

2.  ${\mathrm{t}}_{2\mathrm{g}}^{}$ $$ $4$ ${\mathrm{e}}_{\mathrm{g}}^2$

3.  ${\mathrm{t}}_{2\mathrm{g}}^{}$ $$ $6$ ${\mathrm{e}}_{\mathrm{g}}^0$

4.  ${\mathrm{e}}^3$ ${\mathrm{t}}_2^3$

Which of the following system has maximum number of unpaired electrones –

1. d${}^5$ (Octahedral, low spin)

2. d${}^8$ (Tetrahedral)

3. d${}^6$ (Octahedral, low spin)

4. d${}^3$ (Octahedral)

A complex shown below can exhibit –

1. Geometrical isomerism only
2. Optical isomerism only
3. Both Optical and geometrical isomerism
4. None of the above

The coordination number of a central metal atom in a complex is determined by

1. The number of ligands around a metal ion bonded by sigma and pi-bonds both

2. The number of ligands around a metal ion bonded by pi-bonds

3. The number of ligands around a metal ion bonded by sigma bonds

4. The number of only anionic ligands bonded to the metal ion

Which one of the following complexes is an outer orbital complex :-

1. [Co(NH${}_3$)${}_6$]${}^{3+}$

2. [Mn(CN)${}_6$]${}^{4-}$

3. [Fe(CN)${}_6$]${}^{4-}$

4. [Ni(NH${}_3$)${}_6$]${}^{2+}$

(Atomic nos.:Mn=25 ; Fe=26 ; Co=27 ; Ni = 28)

The IUPAC name for the complex [Co(NO${}_2$) (NH${}_3$)${}_5$ ]Cl${}_2$ is

1. Pentaammine nitrito-N- cobalt (II) chloride

2. Pentaammine nitrito-N- cobalt (III) chloride

3. Nitrito-N- pentaamminecobalt (III) chloride

4. Nitrito-N- pentaamminecobalt (II) chloride

Which among the following complexes can exhibit isomerism?