On what basis is the classification of ligands done?

One mole of the complex compound $Co(NH_3)_5Cl_3$ gives $3$ moles of ions on dissolution in water. One mole of the same complex reacts with two moles of $AgNO_3$ solution to yield two moles of $AgCl_{(s)}$. The structure of the complex is

The correct order of the stoichiometries of $AgCl$ formed when $AgNO_3$ in excess is treated with the complexes $CoCl_3 \cdot 6NH_3$,$CoCl_3 \cdot 5NH_3$,and $CoCl_3 \cdot 4NH_3$ respectively is:

Identify the neutral complex from the following.

Identify a ligand having two donor atoms but uses a pair of electrons of either donor atom to form a coordinate bond.

The secondary valency and the number of hydrogen bonded water molecule$(s)$ in $CuSO_{4} \cdot 5H_{2}O,$ respectively,are :