Many copper compounds, such as CuSO4 and Cu(NO3)2 contain Cu2+ ions. Aqueous solutions of this ion contain the [Cu(H2O)6]2+ complex ion, in which water behaves as a monodentate ligand.

1. (a)Explain what is meant by the term monodentate ligand.[1]
2. (b)Copper(II) sulfate solution, CuSO4(aq), undergoes visible changes with certain reagents. Complete the table below. reagent added to a solution of CuSO4(aq) | observations | formula of the copper(II) compound or complex ion that is formed a few drops of NH3(aq) an excess of NH3(aq) an excess of NaOH(aq) an excess of concentrated HCl(aq)[4]
3. (c)When water is added to concentrated aqueous cobalt(II) chloride the colour of the solution changes from blue to pink. Explain this observation. No equation is needed, but you should include reference to electron movement between orbitals in your answer.[3]
4. (d)When chlorine gas is bubbled into FeSO4(aq) the colour of the solution changes from pale green to yellow. Use data from the Data Booklet to explain this observation. Include an equation in your answer. Reference to electron movement between orbitals is not needed.[2]
5. (e)(i)Write an expression for the stability constant of [FeCl4]-, Kstab. Kstab =[1]
6. (e)(ii)For the above equilibrium the numerical value of Kstab = 0.080. Calculate the concentration of [Fe(H2O)6]3+ in a solution in which the concentration of Cl- is 2.0 mol dm³ and the concentration of [FeCl4]- is 0.10 moldm-³. concentration of [Fe(H2O)6]3+ =[1]