Sketch the shape of a d orbital.

1. (a)Sketch the shape of a d orbital.[1]
2. (b)(i)Explain what is meant by the term transition element.[1]
3. (b)(ii)Name the type of bonding that occurs between a ligand and a transition element.[1]
4. (c)Give the formulae of two oxides of iron. State the oxidation number of iron in each compound.[1]
5. (d)CO and CN⁻ are monodentate ligands. Complete the table for the following two complexes. [Table with metal ion, ligand, co-ordination number, formula of complex ion, charge of complex ion. Rows for Ni²⁺/CO/4 and Fe³⁺/CN⁻/ /3⁻][2]
6. (e)(i)Transition element complexes can exhibit stereoisomerism. [Cu(H₂O)₄(NH₃)₂]²⁺ and Pt(NH₃)₂Cl₂ show the same type of isomerism. Name this type of isomerism.[1]
7. (e)(ii)Complete the three-dimensional diagrams of the two isomers for [Cu(H₂O)₄(NH₃)₂]²⁺ and Pt(NH₃)₂Cl₂. [Figure X.X][2]
8. (f)(i)Copper can form complexes with the ligands ammonia and en, H₂NCH₂CH₂NH₂, as shown. [Cu(H₂O)₆]²⁺(aq) + en(aq) ⇌ [Cu(H₂O)₄(en)]²⁺(aq) + 2H₂O(l) Kstab = 3.98 x 10¹⁰ equilibrium 4 [Cu(H₂O)₆]²⁺(aq) + 2NH₃(aq) ⇌ [Cu(H₂O)₄(NH₃)₂]²⁺(aq) + 2H₂O(l) Kstab = 5.01 × 10⁷ equilibrium 5 Write an expression for the stability constant, Kstab, for equilibrium 5. State its units. Kstab = units =[2]
9. (f)(ii)The standard entropy change, ΔSᵒ, for equilibrium 4 is +23 J K⁻¹ mol⁻¹ and for equilibrium 5 is –8.4 J K⁻¹ mol⁻¹. Suggest an explanation for this difference by reference to both equilibria.[1]
10. (f)(iii)Of the three copper complexes in equilibria 4 and 5, state the formula of the copper complex that is the most stable and explain your choice. copper complex explanation[1]

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