The stabilization of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?

1.	Fe(CO)5	2.	\(\mathrm{Fe(CN)_{6}^{3-}}\)
3.	\(\mathrm{Fe(C_{2}O_{3})_{3}^{3-}}\)	4.	\(\mathrm{[Fe(H_{2}O)_{6}]^{3+}}\)

Indicate the complex ion that shows geometrical isomerism:
1. [Cr(H₂O)₄ Cl₂]⁺
2. [Pt(NH₃)₃ Cl]
3. [Co(NH₃)₆]³⁺
4. [Co(CN)₆]^3-

The CFSE for octahedral${\left[\mathrm{ \; C}oC{l}_6\right]}^{4-}$ is 18,000 cm${}^{-1}$ . The CFSE for tetrahedral will be \(\mathrm{CoCl}_4{ }^{2-}\):${\left[\right]}^{}$\(\mathrm{CoCl}_4{ }^{2-}\)

1. 6000 cm${}^{-1}$

2. 16,000 cm${}^{-1}$

3. 18,000 cm${}^{-1}$

4. 8,000 cm${}^{-1}$

Due to the presence of ambidentate ligands coordination compounds show isomerism. Palladium complexes of the type $\mathrm{Pd}{( {\mathrm{C}}_6{\mathrm{H}}_5 )}_2(\mathrm{NCS}{)}_2$ and $\left[Pd{\left(C_6{H}_5\right)}_2{\left(SCN\right)}_2\right]$ are:

1. Linkage isomers   
2. Coordination isomers
3. Ionization isomers 
4. Geometrical isomers

The compounds [Co(SO${}_4$ (NH${}_3$)${}_5$ ]Br and [Co(SO${}_4$ (NH${}_3$)${}_5$] Cl classified as:

Which of the following species is not expected to be a ligand?

1.  NO

2.  NH${}_4^{+}$

3.  NH${}_2$CH${}_2$CH${}_2$NH${}_2$

4.  CO

Which of the following species is not expected to be a ligand?

1. NO

2. NH${}_4^{+}$

3. ${\mathrm{NH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{NH}}_2$

4. CO

What kind of isomerism exists between [Cr(H₂O)₆]Cl₃ (violet) and [Cr(H₂O)₅Cl]Cl₂⋅H₂O (greyish-green)?

1. Linkage isomerism

2. Solvate isomerism

3. lonisation isomerism

4. Coordination isomerism

IUPAC name of $\left[\mathrm{Pt}{\left({\mathrm{NH}}_3\right)}_2\mathrm{Cl}\right({\mathrm{NO}}_2\left)\right]$ is:

1. Platinum diaminechloronitrite

2. Chloronitrito-N-ammineplatinum (ll)

3. Diamminechloridonitrito-N-platinum (ll)

4. Diamminechloronitrito-N-platinate (ll)

Atomic number of Mn Fe and Co are 25, 26 and 27 respectively. Which of the following inner orbital octahedral complex ions are diamagnetic?

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

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

c.  ${\left[Fe{\left(CN\right)}_6\right]}^{4-}$

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

Choose the correct option
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, c)