Define the term transition metal complex.

1. (a)Define the term transition metal complex.[1]
2. (b)Platinum can form the compound [Pt(NH3)4Cl2][PtCl4]. State the co-ordination numbers and the oxidation numbers of the platinum in the two ions of this compound. co-ordination number [Pt(NH3)4Cl2]2+ [PtCl4]2- oxidation number[2]
3. (c)Draw three-dimensional diagrams to show the structures of the two isomers of [Pt(NH3)4Cl2]2+.[2]
4. (d)Solutions of the compounds [Pt(NH3)4Cl2]Br2 and [Pt(NH3)4Br2]Cl2 can be distinguished from each other by a simple chemical test. Assume that any species bonded to the platinum ion does not react in this test. Complete the table with a test that could be used to positively identify each compound. Give details of expected observations with each compound. test observation with [Pt(NH3)4Cl2]Br2 observation with [Pt(NH3)4Br2]Cl2[2]
5. (e)In this question you should consider geometrical and optical isomerism. What type of isomerism is shown by the following complexes? You should answer geometrical, optical, both or neither. octahedral [Co(NH2CH2CH2NH2)2Cl2]+ square planar [Ni(CN)2Cl2]2- tetrahedral [CuBr2Cl2]2-[3]
6. (f)Many enzymes contain transition metal complexes. Describe, with the aid of a suitably labelled diagram, how an enzyme catalyses the breakdown of a substrate molecule.[3]

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