The compounds $\left[\mathrm{Co}\left(\mathrm{SO}_4\right)\left(\mathrm{NH}_3\right)_5\right] \mathrm{Br}$ and $\left[\mathrm{Co}\left(\mathrm{SO}_4\right)\left(\mathrm{NH}_3\right)_5\right] \mathrm{Cl}$ represent

A chelating agent has two or more than two donor atoms to bind to a single metal ion. Which of the following is not a chelating agent?

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

What kind of isomerism exists between $\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right] \mathrm{Cl}_3$ (violet) and $\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_5 \mathrm{Cl}\right] \mathrm{Cl}_2 \cdot \mathrm{H}_2 \mathrm{O}$ (greyish-green)?

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