Which of the following represents a chelating ligand?

Which coordination compound from the following has a net negative charge on the complex ion?

Explain the classification of ligands on the basis of charge.

In the complex ion $[Fe(C_2O_4)_3]^{3-}$,the coordination number of $Fe$ is

On the basis of the following observations made with aqueous solutions,assign secondary valences to metals in the following compounds:

Formula	Moles of $AgCl$ precipitated per mole of the compound with excess $AgNO_3$
$(i) PdCl_2 \cdot 4NH_3$	$2$
$(ii) NiCl_2 \cdot 6H_2O$	$2$
$(iii) PtCl_4 \cdot 2HCl$	$0$
$(iv) CoCl_3 \cdot 4NH_3$	$1$
$(v) PtCl_2 \cdot 2NH_3$	$0$

What type of ligand is ethylenediamine?