Which of the following is a bidentate ligand?

What is the formula of ferric ferrocyanide?

Which statement about the coordination number of a cation is true?

Primary and Secondary valency of $Co$ in the complex compound $[Co(en)_3]Cl_3$ is respectively . . . . . . .

$A$ coordination complex compound of cobalt has a molecular formula containing five ammonia molecules,one nitro group,and two chlorine atoms for one cobalt atom. One mole of this compound produces three moles of ions in an aqueous solution,and upon reacting with an excess of $AgNO_3$,it forms $AgCl$ precipitate. The ionic formula for this complex would be:

How many molecules of $EDTA$ (Ethylenediaminetetraacetic acid) are required to form an octahedral complex with a $Ca^{2+}$ ion?