The number of hydrogen-bonded water molecule$(s)$ associated with the stoichiometry $CuSO_{4} \cdot 5H_{2}O$ is .... .

Compound $PdCl_4 \cdot 6H_2O$ is a hydrated complex; $1 \ m$ aqueous solution of it has a freezing point of $269.28 \ K$. Assuming $100\%$ ionization of the complex,calculate the molecular formula of the complex ($K_f$ for water $= 1.86 \ K \ kg \ mol^{-1}$,freezing point of pure water $= 273 \ K$).

$A$ brown ring is formed in the ring test for $NO_{3}^{-}$ ion. It is due to the formation of :-

$CrCl_3 \cdot xNH_3$ can exist as a complex. $A$ $0.1 \ m$ aqueous solution of this complex shows a depression in freezing point of $0.558^{\circ} C$. Assuming $100 \%$ ionisation of this complex and that the coordination number of $Cr$ is $6$,the complex will be: (Given $K_f = 1.86 \ K \ kg \ mol^{-1}$)

The molecular formula of a cobalt coordination complex contains five ammonia molecules,one nitro group,and two chlorine atoms for one cobalt atom. In an aqueous solution,one mole of the substance produces $3$ moles of ions. Upon reacting this solution with an excess of silver nitrate solution,$2$ moles of $AgCl$ precipitate are obtained. What is the ionic formula of the complex?

During the estimation of nickel,we prepare nickel dimethylglyoxime,a scarlet red solid. This compound is . . . . . . .