Considering H₂O as a weak field ligand, the number of unpaired electrons in \([Mn(H_{2}O)_{6}]^{2+}\) will be:
(At. no. of Mn = 25)

1.	Five	2.	Two
3.	Four	4.	Three

Among [Ni(CO)₄], [Ni(CN)₄]²⁻, [ NiCl₄]²⁻ species, the hybridization states of the Ni atom are respectively:
(At. No. of Ni = 28)

Coordination compound that would exhibit optical isomerism is:

The atomic numbers of Cr and Fe are respectively 24 and 26. Among the following, the one that is paramagnetic with the spin of the electron is:

1. CrCO₆

2. FeCO₅

3. [Fe(CN)₆]^4-

4. [Cr(NH₃)₆]³⁺

The hypothetical complex
chlorodiaquatriamminecobalt(III) chloride can be
represented as:

1. $\left[\mathrm{CoCl}{\left({\mathrm{NH}}_3\right)}_3{\left({\mathrm{H}}_2\mathrm{O}\right)}_2\right]{\mathrm{Cl}}_2$

2. $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_3\left({\mathrm{H}}_2\mathrm{O}\right){\mathrm{Cl}}_3\right]$

3. $\left[\mathrm{Co}{\left({\mathrm{NH}}_2\right)}_3{\left({\mathrm{H}}_2\mathrm{O}\right)}_2\mathrm{Cl}\right]$

4. $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_3{\left({\mathrm{H}}_2\mathrm{O}\right)}_3{\mathrm{Cl}}_3\right]$

The coordination compound that gives the maximum number of isomers is:

1. [Co(NH₃)₄Cl₂]

2. [Ni(en)(NH₃)₄]²⁺

3. [Ni(C₂O₄)(en)₂]

4. [Cr(SCN)₂(NH₃)₄]⁺

According to IUPAC nomenclature, sodium nitroprusside is named as:

1. Sodium nitro ferricyanide

2. Sodium nitro ferrocyanide

3. Sodium pentacyanidonitrosyl ferrate(II)

4. Sodium pentacyanonitrosyl ferrate(III)

The number of unpaired electrons in the complex ion [CoF₆]^3– is:

(Atomic No. Co = 27)

1. 2

2. 3

3. 4

4. Zero

The octahedral complex that will not show geometrical isomerism is: 
 (A and B are monodentate ligands)

A metal ion present in vitamin B₁₂ is: