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?

$\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_5\mathrm{Br}\right]Cl$ and $\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_5\mathrm{Cl}\right]Br$  can be distinguished by/and isomerism shown is:

1. ${\mathrm{BaCl}}_2$, ionisation

2. ${\mathrm{AgNO}}_3$, ionisation

3. ${\mathrm{AgNO}}_3$, coordinate

4. ${\mathrm{BaCl}}_2$, linkage

${\left[{\mathrm{Fe}}^{\mathrm{II}}\mathrm{Cl}{\left(\mathrm{CN}\right)}_4\left({\mathrm{O}}_2\right)\right]}^{4-}$ is named as:

1. Chlorotetracyanodioxoferrate (II) ion

2. Chlorotetracyanoperoxoferrate (II) ion

3. Chlorotetracyanosuperoxoferrate (II) ion

4. None of the correct

Geometrical isomerism in coordination compunds is exhibited by
1. Square planar and tetrahedral complexes
2. Square planar and octahedral complexes
3. Tetrahedral and octahedral complexes
4. Squre planar, tetrahedral and octahedral complexes

Which of the following is not optically active?

1. ${\left[\mathrm{Co}{\left(\mathrm{en}\right)}_3\right]}^{3+}$

2. ${\left[\mathrm{Cr}{\left(\mathrm{ox}\right)}_3\right]}^{3-}$

3. $\mathrm{cis}-{\left[{\mathrm{CoCl}}_2{\left(\mathrm{en}\right)}_2\right]}^{+}$

4. $\mathrm{trans}-{\left[{\mathrm{CoCl}}_2{\left(\mathrm{en}\right)}_2\right]}^{+}$