Topic 15
Transition
Metals
Topic 15 is in two parts. Topic 15A, principles of transition metal chemistry, covers electronic configurations of the d-block atoms and ions, variable oxidation number, ligands and dative (coordinate) bonding, coordination number, the shapes of complex ions, the origin of colour, cis-platin and haemoglobin. Topic 15B, reactions of transition metal elements, covers the redox chemistry of vanadium and chromium using E⦵ values, reactions of aqueous metal ions with sodium hydroxide and ammonia, ligand exchange and the stability of complexes, and heterogeneous catalysis, homogeneous catalysis and autocatalysis.
Revision Notes
8 revision notes, in the order the specification teaches them.
Electron Configurations and Properties of Transition metals
Transition metals: electron configurations of d-block atoms and ions, the definition of a transition metal and variable oxidation numbers.
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Ligands, Complex Ions and Their Shapes
Ligands and complex ions: dative (coordinate) bonds, coordination number, bidentate and multidentate ligands and the shapes of complexes.
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Colour of Transition metal Ions
The colour of transition metal ions: d-orbital splitting, absorption of visible light and the effect of oxidation number, ligand and coordination number.
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Ligand exchange and the Stability of Complexes
Ligand exchange in copper(II) and cobalt(II) complexes, the chelate effect and entropy.
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Redox Chemistry of Transition metals
Transition metal redox reactions: vanadium oxidation states, chromium and dichromate(VI) and colour changes.
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Reactions of Metal Ions with Sodium Hydroxide and Ammonia
Reactions of aqueous metal ions with sodium hydroxide and ammonia: precipitate colours, ionic equations and amphoteric hydroxides.
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Heterogeneous Catalysis
Transition metals as heterogeneous catalysts: surface adsorption, V₂O₅ in the Contact process and catalytic converters.
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Homogeneous Catalysis and Autocatalysis
Homogeneous catalysis: Fe²⁺ with I⁻ and S₂O₈²⁻, and autocatalysis by Mn²⁺ in the MnO₄⁻ and C₂O₄²⁻ reaction.
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Transition Metals Map
Edexcel A Level Chemistry · Topic 15 Transition Metals and Complexes
The whole section on one A4 page: what makes a transition metal, configurations, oxidation numbers, ligands and complexes, multidentate ligands, and cisplatin and haemoglobin.
Transition Metal Reactions Map
Edexcel A Level Chemistry · Topic 15 Colour, Redox and Reactions of Ions
The whole section on one A4 page: why ions are coloured, changing the colour, vanadium, chromium, hydroxide precipitates, excess ammonia and Core Practical 12.
Exchange and Catalysis Map
Edexcel A Level Chemistry · Topic 15 Ligand Exchange and Catalysis
The whole section on one A4 page: ligand exchange, the chelate effect, heterogeneous and homogeneous catalysts, V₂O₅, catalytic converters and autocatalysis.
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15
- A.1
be able to deduce the electronic configurations of atoms and ions of the d-block elements of period 4 (Sc–Zn), given the atomic number and charge (if any)
Revise - A.2
know that transition metals are d-block elements that form one or more stable ions with incompletely-filled d-orbitals
Revise - A.8
understand that the colour of aqueous ions, and other complex ions, results from the splitting of the energy levels of the d-orbitals by ligands
Revise - A.10i
understand that colour changes in transition metal ions may arise from changes in oxidation number
Revise - A.10ii
understand that colour changes in transition metal ions may arise as a result of changes in: ligand
Revise - A.10iii
understand that colour changes in transition metal ions may arise as a result of changes in: coordination number
Revise - A.13
understand why complexes with six-fold coordination have an octahedral shape, such as those formed by metal ions with H2O, OH− and NH3 as ligands
Revise - A.14
know that transition metal ions may form tetrahedral complexes with relatively large ligands such as Cl−
Revise - A.15
know that square planar complexes are also formed by transition metal ions and that cis-platin is an example of such a complex
Revise - A.16
understand why cis-platin used in cancer treatment is supplied as a single isomer and not in a mixture with the trans form
Revise - A.18
know that haemoglobin is an iron(II) complex containing a multidentate ligand The structure of the haem group will not be assessed.
Revise - A.19
know that a ligand exchange reaction occurs when an oxygen molecule bound to haemoglobin is replaced by a carbon monoxide molecule
Revise - B.21 a
understand redox reactions for interconversion of vanadium +5 and +4 using relevant Eo values
Revise - B.21 b
understand redox reactions for interconversion of vanadium +4 and +3 using relevant Eo values
Revise - B.21 c
understand redox reactions for interconversion of vanadium +3 and +2 using relevant Eo values
Revise - B.22i
understand, in terms of the relevant Eo values, that the dichromate(VI) ion, Cr2O72−: can be reduced to Cr3+ and Cr2+ ions using zinc in acidic conditions
Revise - B.22ii
understand, in terms of the relevant Eo values, that the dichromate(VI) ion, Cr2O72−: can be produced by the oxidation of Cr3+ ions using hydrogen peroxide in alkaline conditions (followed by acidification)
Revise - B.23
know that the dichromate(VI) ion, Cr2O72−, can be converted into chromate(VI) ions as a result of the equilibrium 2CrO42−+ 2H+ ⇌ Cr2O72−+ H2O
Revise - B.24 a
be able to record observations and write suitable equations for reactions of Cr3+(aq) with aqueous sodium hydroxide, including in excess
Revise - B.24 b
be able to record observations and write suitable equations for reactions of Fe2+(aq) with aqueous sodium hydroxide, including in excess
Revise - B.24 c
be able to record observations and write suitable equations for reactions of Fe3+(aq) with aqueous sodium hydroxide, including in excess
Revise - B.24 d
be able to record observations and write suitable equations for reactions of Co2+(aq) with aqueous sodium hydroxide, including in excess
Revise - B.24 e
be able to record observations and write suitable equations for reactions of Cu2+(aq) with aqueous sodium hydroxide, including in excess
Revise - B.24 f
be able to record observations and write suitable equations for reactions of Cr3+(aq) with aqueous ammonia, including in excess
Revise - B.24 g
be able to record observations and write suitable equations for reactions of Fe2+(aq) with aqueous ammonia, including in excess
Revise - B.24 h
be able to record observations and write suitable equations for reactions of Fe3+(aq) with aqueous ammonia, including in excess
Revise - B.24 i
be able to record observations and write suitable equations for reactions of Co2+(aq) with aqueous ammonia, including in excess
Revise - B.24 j
be able to record observations and write suitable equations for reactions of Cu2+(aq) with aqueous ammonia, including in excess
Revise - B.26i
understand that ligand exchange, and an accompanying colour change, occurs in the formation of: [Cu(ΝΗ3)4(Η2Ο)2]2+ from [Cu(Η2Ο)6]2+ via Cu(OH)2(Η2Ο)4
Revise - B.26ii
understand that ligand exchange, and an accompanying colour change, occurs in the formation of: [CuCl4]2− from [Cu(Η2Ο)6]2+
Revise - B.26iii
understand that ligand exchange, and an accompanying colour change, occurs in the formation of: [CoCl4]2− from [Co(Η2Ο)6]2+
Revise - B.27
understand that the substitution of small, uncharged ligands (such as H2O) by larger, charged ligands (such as Cl−) can lead to a change in coordination number
Revise - B.28
understand, in terms of the large positive increase in ΔSsystem, that the substitution of a monodentate ligand by a bidentate or multidentate ligand leads to a more stable complex ion
Revise - B.30
know that a heterogeneous catalyst is in a different phase from the reactants and that the reaction occurs at the surface of the catalyst
Revise - B.31
understand, in terms of oxidation number, how V2O5 acts as a catalyst in the contact process
Revise - B.32i
understand how a catalytic converter decreases carbon monoxide and nitrogen monoxide emissions from internal combustion engines by: adsorption of CO and NO molecules onto the surface of the catalyst
Revise - B.32ii
understand how a catalytic converter decreases carbon monoxide and nitrogen monoxide emissions from internal combustion engines by: weakening of bonds and chemical reaction
Revise - B.32iii
understand how a catalytic converter decreases carbon monoxide and nitrogen monoxide emissions from internal combustion engines by: desorption of CO2 and N2 product molecules from the surface of the catalyst
Revise
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