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

Identify the total number of complexes having bidentate ligands in them from the following list of complexes:
$a$) Tetracyanonickelate$(II)$ ion
$b$) Trioxalatocobaltate$(III)$ ion
$c$) Sodium hexafluoroaluminate$(III)$
$d$) bis(ethylenediamine)dithiocyanatoplatinum$(IV)$

Which of the following complexes contains an anionic ligand?

What is the coordination number of $Co$ in the complex $[CoF_6]^{3-}$?

Number of ions present in $K_4[Fe(CN)_6]$

The ligand $N[CH_2CH_2NH_2]_3$ is a: