In $[Ag(CN)_2]^-$,the number of $\pi$ bonds is

$A$ ligand which has two different donor atoms and either of the two ligates with the central metal atom/ion in the complex is called $\qquad$

In the complex acetylbromidodicarbonylbis(triethylphosphine)iron$(II)$,the number of $Fe-C$ bond$(s)$ is

The molecular formula of a coordination complex is $CoH_{12}O_6Cl_3$. When one mole of this aqueous solution of the complex is reacted with an excess of aqueous $AgNO_3$ solution,$3$ moles of $AgCl$ are formed. What is the correct formula of the complex?

Which of the following complexes gives a white precipitate with a solution of barium chloride $(BaCl_2)$?

Which of the following statements is incorrect for $EDTA$?