For the following complex, draw a crystal field energy-level diagram, assign the electrons to the orbitals, and predict the number of unpaired electrons:

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

For the following complex, draw a crystal field energy-level diagram, assign the electrons to the orbitals, and predict the number of unpaired electrons:

${\left[\mathrm{Cu}(\mathrm{en}{)}_3\right]}^{2+}$

For the following complex, draw a crystal field energy-level diagram, assign the electrons to the orbitals, and predict the number of unpaired electrons:

${\left[{\mathrm{FeF}}_6\right]}^{3-}$

Arrange the following in the increasing order of the molar conductance.

$\left(\mathrm{i}\right)$ $\left[{\mathrm{CoCl}}_3{\left({\mathrm{NH}}_3\right)}_3\right]$,

$\left(\mathrm{ii}\right)$ $\left[\mathrm{CoCl}{\left({\mathrm{NH}}_3\right)}_5\right]{\mathrm{Cl}}_2$,

$\left(\mathrm{iii}\right)$ $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$,

$\left(\mathrm{iv}\right)$ $\left[{\mathrm{CoCl}}_2{\left({\mathrm{NH}}_3\right)}_4\right]\mathrm{Cl}$

Arrange the following in the increasing order of the tendency of $\sigma$ donation.

$\mathrm{C}, \mathrm{N}, \mathrm{O}, \mathrm{F}\left(\mathrm{halogen}\right)$

Arrange the following in the increasing order of the strength of the ligands:

$\left(1\right) \mathrm{Br}, \left(2\right) {\mathrm{S}}^{2-}, \left(3\right) {\mathrm{NO}}_2^{-}, \left(4\right) \mathrm{CO}, \left(5\right) {\mathrm{H}}_2\mathrm{O}, \left(6\right) {\mathrm{CN}}^{-}, \left(7\right) {\mathrm{NH}}_3, \left(8\right) {\mathrm{NO}}_3^{-}$

Among the given options, which complex is diamagnetic?

(i) $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$,

(ii) $\left[\mathrm{Ni}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_2$,

(iii) $\left[\mathrm{Cr}\left({\mathrm{H}}_2{\mathrm{O}}_6\right)\right]{\mathrm{Cl}}_3$,

(iv) $\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]{\mathrm{Cl}}_2$