BEGINNER'S BOX

Among $\mathrm{Ni}(\mathrm{CO}{)}_4,{\left[\mathrm{Ni}(\mathrm{CN}{)}_4\right]}^{2-}$ and $\left[{\mathrm{NiCl}}_4^{2-}\right]$

The stability constants of the complexes formed by a metal ion $\left({\mathrm{M}}^{2+}\right)$ with ${\mathrm{NH}}_3, {\mathrm{CN}}^{-}, {\mathrm{H}}_2\mathrm{O}$ and $\mathrm{en}$ are of the order ${10}^{11}, {10}^{27}, {10}^{15} \text{\&} {10}^8$, respectively. Then, ______.

Which of the following does/do not exhibit optical isomerism

The number of geometrical isomers of $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_3{\left({\mathrm{NO}}_3\right)}_3\right]$ :

${\mathrm{K}}_4\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]$ reacts with ${\mathrm{FeCl}}_3$ to form :-

In the complex ion $\left[\mathrm{Fe}\right(\mathrm{EDTA}){]}^{-}$ the coordination number and oxidation state of central metal ion is:

Which of the following has least conductivity in aqueous solution.
 

Select bidentate or didentate ligand from the following.