The reaction of $Pb(NO_3)_2$ and $NaCl$ in water produces a precipitate that dissolves upon the addition of $HCl$ of appropriate concentration. The dissolution of the precipitate is due to the formation of

Which of the following cations forms the least stable complex with the same ligand?

When ammonia is added to a cupric salt solution,the deep blue colour is observed; it is due to the formation of

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?

Which of the following has the highest molar conductivity in solution?

What is meant by the chelate effect? Give an example.