Number of water molecules in Mohr's salt is

Which of the following is a chelating ligand?

Consider the following complex $[Co(NH_3)_5CO_3]ClO_4$. The coordination number,oxidation number,number of $d-$ electrons,and number of unpaired $d-$ electrons on the metal are respectively:

Consider the following statements according to Werner's theory:
$(a)$ Ligands are connected to the metal ions by coordinate bonds.
$(b)$ Secondary valencies have directional properties.
$(c)$ Secondary valencies are non-ionisable.
Of these statements:

$A$ complex compound of $Co^{3+}$ with molecular formula $CoCl_{x} \cdot yNH_3$ gives a total of $3$ ions when dissolved in water. How many $Cl^{-}$ ions satisfy both primary and secondary valencies in this complex?

$A$ coordination compound $CrCl_{3} \cdot 4 H_{2} O$ precipitates silver chloride when treated with silver nitrate. The molar conductance of its solution corresponds to a total of two ions. Write the structural formula of the compound and name it.