1.1. 12.2 g of hydrated iron (II) sulfate, FeSO₄.xH₂O were dissolved in acidic solution and made up to a volume of 500 cm³.  A 25.0 cm³ sample of this solution was titrated against 0.0200 mol dm^-3 potassium manganate (VII) solution.  21.95 cm³ of this solution were required.

i) Give an equation for the reaction between iron (II) ions and manganate ions.

ii) State the colour change that occurs at the end-point.

iii) Calculate the value of x in FeSO₄.xH₂O.

1.2. Complexes of [Pt(NH₃)₂Cl₂] and [Ni(H₂NCH₂CH₂NH₂)₃]²⁺ exhibit different forms of stereoisomerism.

i) State the type of stereoisomerism shown by each of the complexes.

ii) Draw the isomers of each complex.

iii) Give a use of an isomer of [Pt(NH₃)₂Cl₂].

iv) Explain why [Ni(H₂NCH₂CH₂NH₂)₃]²⁺ has a 2+ charge overall.

1.3. Transition metals and their compounds are important catalysts.

i) Explain the term heterogeneous catalyst.

ii) Name the heterogeneous catalyst used in the Haber Process.

iii) Heterogeneous catalysts work by chemisorption. Explain this process.

iv) Explain why heterogeneous catalysts can become ineffective as a result of impurities. 

1.4. The reaction of manganate (VII) ions with ethanedioate ions is initially very slow. However, the reaction is catalysed by manganese (II) ions which are formed in the reaction.

i) Give an equation for the reaction between manganate (VII) ions and ethanedioate ions using the half equations below.

MnO₄^- + 8H⁺ + 5e^- → 2Mn²⁺ + 4H₂O

C₂O₄^2- → 2CO₂ + 2e^-

ii) Explain why the reaction can be monitored using colorimetry.

iii) Sketch a graph of concentration of manganate (VII) ions against time. Explain the shape of the graph.