In which of the following compounds,the transition metal is in an oxidation state of zero?

Three moles of $AgCl$ get precipitated when one mole of an octahedral coordination compound with empirical formula $CrCl_{3} \cdot 3NH_{3} \cdot 3H_{2}O$ reacts with excess of silver nitrate. The number of chloride ions satisfying the secondary valency of the metal ion is $......$

How many water molecules are hydrogen bonded in the following molecular formula $[Cu(H_{2}O)_{4}]^{2+} SO_{4}^{2-} \cdot H_{2}O$?

How many ions will be obtained by ionization of ferric hexacyanoferrate$(III)$ complex compound?

On what basis is the classification of ligands done?

Given below are two statements :
Statement $I :$ The identification of $Ni^{2+}$ is carried out by dimethyl glyoxime in the presence of $NH_{4}OH$.
Statement $II :$ The dimethyl glyoxime is a bidentate neutral ligand.
In the light of the above statements,choose the correct answer from the options given below: