Which of the following ligands forms a chelate?

The homoleptic complex in the following is

One mole of the coordination compound $Co(NH_3)_5Cl_3$ gives $3$ moles of ions upon dissolution in water. Furthermore,one mole of this complex reacts with $2$ moles of $AgNO_3$ solution to produce $2$ moles of $AgCl(s)$. The structure of the complex is:

What type of ligand is $EDTA$?

Which of the following coordination complexes contains the ligand $en$?

Total number of moles of $AgCl$ precipitated on addition of excess of $AgNO_3$ to one mole each of the following complexes $[Co(NH_3)_4Cl_2]Cl$,$[Ni(H_2O)_6]Cl_2$,$[Pt(NH_3)_2Cl_2]$ and $[Pd(NH_3)_4]Cl_2$ is $...............$ (in $.00$)