Which of the following ligands forms the maximum number of $5$-membered rings with a central metal atom?

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

Which among the following is a monodentate ligand?

Given the molecular formulas of the hexa-coordinated complexes: $(a)$ $CoCl_3 \cdot 6NH_3$,$(b)$ $CoCl_3 \cdot 5NH_3$,$(c)$ $CoCl_3 \cdot 4NH_3$. If the number of coordinated $NH_3$ molecules in $(a)$,$(b)$,and $(c)$ are $6, 5$,and $4$ respectively,the primary valencies in $(a)$,$(b)$,and $(c)$ are:

The anion of acetylacetone $(acac)$ forms $Co(acac)_3$ chelate with $Co^{3+}.$ The rings of the chelate are

What is the number of moles of ionisable $Cl^{-}$ ions in a coordination complex if it forms $2 \ moles$ of $AgCl$ when treated with silver nitrate solution in excess?