Which of the following ligands is ambidentate?

$2.33 \ g$ of compound $X$ (empirical formula $= CoH_{12}N_{4}Cl_{3}$) upon treatment with excess $AgNO_{3}$ solution produces $1.435 \ g$ of a white precipitate. The primary and secondary valences of cobalt in compound $X$,respectively are.
[Given,atomic mass : $Co = 59, Cl = 35.5, Ag = 108$]

What is the coordination number of the metal in $[Co(en)_2Cl_2]$?

Select the correct statements about the $PtCl_4 \cdot 4NH_3$ complex salt:
$I.$ All the chlorides are bonded by primary valency.
$II.$ All the chlorides are bonded by secondary valency.
$III.$ All the $NH_3$ are bonded by secondary valency.
$IV.$ Half of the chlorides are bonded with secondary valency.

What is the total number of ligands present in $[CoCl_{2}(NH_{3})_{4}]Cl$?

Which of the following complexes contains only neutral ligands?