How many donor groups (donor atoms) are present in diethylene triamine?

Which of the following complexes contains only neutral ligands?

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

In complex compounds,ligands act as:

What is the coordination number of $Co$ in $[CoCl_2(NH_3)_4]^+$?

Which among the following statements is wrong regarding Mohr's salt?