What is the coordination number of the central metal ion in $[Fe(C_2O_4)_3]^{3-}$?

The ligand $N(CH_2-CH_2-NH_2)_3$ is : $-$

Give the chemical formulas for the following compounds:
$(i)$ Ammonium molybdate
$(ii)$ Ammonium phosphomolybdate
$(iii)$ Ferric thiocyanate ion
$(iv)$ Sodium sulphide

$EDTA$ (Ethylenediaminetetraacetate ion) is a hexadentate ligand. Identify the number of donor atoms in an $EDTA$ molecule that form coordinate bonds with a central metal atom or ion in a complex.

In $EDTA^{4-}$,the donor atoms are:

$A$ complex of platinum,ammonia,and chloride produces four ions per molecule in the solution. Which structure is consistent with this observation?