What type of ligand is ethylenediamine?

Which of the following is a neutral ligand?

Which compound is a zero-valent metal complex?

Which of the following ligands is ambidentate?

The number of moles of $AgCl$ precipitate formed when an excess of $AgNO_3$ is added to one mole of $[Cr(NH_3)_4Cl_2]Cl$ is:

Addition of excess of $AgNO_3$ to an aqueous solution of $1$ mole of $PdCl_2 \cdot 4 NH_3$ gives $2$ moles of $AgCl$. The conductivity of this solution corresponds to