1. Match the metal to its use...
TRANSITION METALS
Match the metal to its use...
Titanium
Vanadium
Chromium
Manganese
Iron
Cobalt
Nickel
Copper

2. Copper Electrical wiring
Higher conductivity per unit volume than any other metal except silver.

3. Vanadium
Jigsaw blades

4. Plate bike parts Resistant to corrosion and looks lustrous.
Chromium
Plate bike parts
Resistant to corrosion and looks lustrous.

5. Keeps a remarkably constant resistance despite changes in temperature.
Manganese
Alloy wire resistor
Keeps a remarkably constant resistance despite changes in temperature.

6. Iron
Sword
Took over the Bronze Age as it was stronger than its bronze equivalent.

7. Cobalt
Permanent magnets

8. Can operate at very high temperatures without burning out.
Nickel
Toaster filaments
Can operate at very high temperatures without burning out.

9. Titanium
Concorde (alloy)

10. WHAT ARE TRANSITION ELEMENTS?
Transition elements are metals that contain an incomplete d sub shell in atoms or ions.
Top row transition metals: Ti – Cu
Zn AND Sc are not a transition metal
(Zn & Zn2+)
(Sc & Sc3+)
© A Jul-12

11. PROPERTIES OF TRANSITION METALS?
1) They form coloured ions.
photo by Ian Geldard

12. What properties do transition metals have?

13. Task 1 Write out the short hand electron configuration of all the transition elements in Period 4.

14. K2Cr O4
Co(NO3 )2
CuSO4
NiCl2
K2Cr2O7
KMnO4

15. What are the transition elements?
Where are they found?
What defines them?
Are there any exceptions?
Why do these exceptions exist?
How do we write electron configurations?
What are the rules?
Aufbau principle
Pauli exclusion principle
Hunds’ rule

17. ELECTRON STRUCTURES Fe [Ar] 4s2 3d6 Cu [Ar] 4s1 3d10 Fe3+ [Ar] 3d5 Cu+
4s fills and empties before 3d Fe
[Ar] 4s2 3d6 Cu
[Ar] 4s1 3d10
Fe3+
[Ar] 3d5
Cu+
[Ar] 3d10 Sc
[Ar] 4s2 3d1
Cu2+
[Ar] 3d9
Sc3+
[Ar] Zn
[Ar] 4s2 3d10 V
[Ar] 4s2 3d3
Zn2+
[Ar] 3d10
V2+
[Ar] 3d3 Cr
[Ar] 4s1 3d5
© A Jul-12

18. More exceptions... Chromium Copper
Why does the 4s sub-shell lose electrons first?
How do we write electron configurations of T.M. ions.?

19. Electron configuration
Transition elements Ti V Cr Mn Fe Co Ni Cu

20. Progress Check Questions
The only ion forms by Scandium in Sc3+. The Only ion formed by Zinc is Zn2+. Explain why Scandium and Zinc are not transition metals by referring to the electron configurations of these two ions.
Titanium forms 3 ions: Ti2+, Ti3+and Ti4+. Explain why Titanium is considered to be a transition element using the electron configuration of the 3 ions.

21. What would you do differently to answer this question now and why?
Plenary Write out the full electron configuration of all the transition elements in Period 4.
What would you do differently to answer this question now and why?

22. What is a catalyst? How does it work? What examples can you think of?
STARTER QUESTIONS
What is a catalyst?
How does it work?
What examples can you think of?

23. What is a catalyst? How does it work? What examples can you think of?
STARTER QUESTIONS
What is a catalyst?
How does it work?
What examples can you think of?
A catalyst is a substance that speeds up the rate of a reaction. It remains chemically unchanged at the end of a reaction.
Catalysts work by providing alternative routes with lower activation energy

24. Why are transition metals effective catalysts?
ADSORPTION
Reactants are adsorbed onto the surface and held in place while the reaction takes place.
Products are desorbed and the metal remains unchanged.
VARIABLE OXIDATION STATES
Bind to reactants due to loss / gain of electrons and form intermediates with a lower activation energy.
Because they can change oxidation states.
Electrons can be lost / gained from d-subshells.
The transfer of electrons can speed up reactions.

25. USES OF SOME COMPLEXES V2O5 Catalyst in Contact process Mn2+
Autocatalyst in MnO4 / C2O42- titrations
haemoglobin
Contains Fe2+ – allows O2 to bond and carried to where needed
[Pt(NH3)2Cl2]
cis platin – anti-cancer drug
[Ag(NH3)2]+
Used in Tollen's reagent to distinguish aldehydes and ketones
[Ag(CN)2] -
Used in silver electroplating
© A Jul-12

26. Haber Process What does it make? What is the catalyst?
How does it work?
What does
‘heterogeneous catalysis’
mean?
What is the commercial
use of the product?

27. Contact Process What does it make? What is the catalyst?
What is the commercial
use of the product?

28. Hydrogenation What does it make? What is the catalyst?
How does it work?
What is the commercial
use of the product?

29. Decomposition of Hydrogen Peroxide
What does it make?
What is the catalyst?
What is the use?

30. Precipitation Reactions
What happens during a precipitation reaction?
Complete the simple test-tube experiments to show how we can identify the following ions;
Co2+ Fe Fe3+ Cu2+

31. Complex Ions What is a complex ion? What is a co-ordinate bond?
What is a ligand?

32. [Cu(H2O)6]

33. SHAPES OF COMPLEX IONS Co-ordination number 2 4 6 Shape linear
tetrahedral
square planar
octahedral
Bond angles
Occurrence
e.g.
© A Jul-12

34. SHAPES OF COMPLEX IONS Co-ordination number 2 4 6 Shape linear
tetrahedral
square planar
octahedral
Bond angles
180º
109½º
90º
Occurrence
Ag+ complexes
Large ligands (e.g. Cl-)
Pt2+
complexes
Commonest
e.g.
[Ag(NH3)2]+
[CuCl4]2-
[PtCl4]2-
[Cu(H2O)6]2+
© A Jul-12

35. SHAPES OF COMPLEX IONS For each of the following complexes:
Draw the complex.
Name the shape.
Show bond angles.
Give the metal oxidation state.
Give the co-ordination number.
[Ag(CN)2]-
[Cr(NH3)6]3+
[Ni(en)3]2+
[Co(en)2Cl2 ]+
[Pt(NH3)2Cl2]
[Fe(C2O4)3]4-
© A Jul-12

36. SHAPES OF COMPLEX IONS Linear 180º Ag +1 Co-ordination number = 2 1 2
Octahedral
90º
Cr +3
Co-ordination number = 6
© A Jul-12

37. SHAPES OF COMPLEX IONS Octahedral 90º Ni +2 Co-ordination number = 6 32+
Octahedral
90º
Ni +2
Co-ordination number = 6 3 Ni 4
Octahedral
90º
Co +3
Co-ordination number = 6
© A Jul-12

38. SHAPES OF COMPLEX IONS Square Planar 90º Pt +2
Co-ordination number = 4 5 6
Octahedral
90º
Fe +2
Co-ordination number = 6 4- Fe
© A Jul-12

39. METAL AQUA IONS complex colour [Cu(H2O)6]2+ blue [Co(H2O)6]2+ pink
[Fe(H2O)6]2+
green
[V(H2O)6]2+
[Cr(H2O)6]3+
violet*
[Fe(H2O)6]3+
pale violet**
[Al(H2O)6]3+
colourless
© A Jul-12

40. FORMATION OF COLOURED IONS

41. FORMATION OF COLOURED IONS
Once ligands bond, the five d orbitals are no longer have the same energy.
Energy = h
Energy is absorbed to excite electrons from the lower d orbitals to the higher d orbitals.
This energy is in the uv/visible region.
© A Jul-12

42. FORMATION OF COLOURED IONS

43. FORMATION OF COLOURED IONS
Colorimetry
The more concentrated the solution, the more it absorbs.
This can be used to find the concentration of solutions – this is done in colorimeters.
For some ions, a ligand is added to intensify the colour.
The strength of absorption of solutions of known concentration is measured and a graph produced.
The concentration of a solution of unknown concentration can be found by measuring the absorption and using the graph.
© A Jul-12

44. FORMATION OF COLOURED IONS
Colorimetry

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51. Ligands
Monodentate ligands / Unidentate
Multidentate ligands

52. Shapes

53. Identify which of the following elements are transition metals...
copper
copper
zinc
iron
iron
yttrium
mercury
cobalt
cobalt
sodium
scandium
chromium
chromium
calcium

54. What makes them transition metals?....
Complete the noble gas electron configuration for the metals highlighted below (in order):
copper
zinc
iron
yttrium
mercury
cobalt
sodium
scandium
chromium
calcium

56. Complex Ions of the transition elements
For your given information you must:
a) make the model
b) draw the diagram
c) write out the formula for the ion including charge
d) state the coordination number
e) state whether the ligand is unidentate, bidentate etc.
f) determine the shape of the ion
g) complete b-f for the other models made by everyone else! A table might be a good idea! (Include an end column for other information that will be included later.)

57. Complex Ions of the transition elements
Transition Metal Ion
Ni2+
Ligand
Cyanide
(a larger ligand)
N.B. NOT tetrahedral

58. Complex Ions of the transition elements
Transition Metal Ion
Co3+
Ligand
Chloride
(a larger ligand)

59. Ag+ (NH3)2 (forms a linear complex)
Complex Ions of the transition elements
Transition Metal Ion
Ag+
Ligand
(NH3)2
(forms a linear
complex)
This complex ion is Tollen's Reagent. What does it do?

60. Complex Ions of the transition elements
Transition Metal Ion
V2+
Ligand
Benzene-1,2-diol
(a neutral,
bidentate ligand – hint
work out where the
LP's are)

61. Complex Ions of the transition elements
Transition Metal Ion
Cu2+
Ligand
Water
(a smaller ligand)

62. Complex Ions of the transition elements
Transition Metal Ion
Fe3+
Ligand
Fluoride
(a smaller ligand)

63. Complex Ions of the transition elements
Transition Metal Ion
Pt2+
Ligand
2 ammonia
2 chloride
N.B. NOT tetrahedral
This complex ion is cis-platin. It is an anticancer drug. It prevents the replication of cancer cells, however it is not selective in its prevention and can also impact normal cells. (p219 in textbook)

64. Complex Ions of the transition elements
Transition Metal Ion
Ni2+
Ligand
Cyanide
(a larger ligand)
N.B. NOT tetrahedral

65. Complex Ions of the transition elements
Transition Metal Ion
Cr3+
Ligand
Ethane-1,2-diamine
(often abbreviated to (en)
this is a bidentate ligand
that can form a 6 CN ion –
work out where the LP's
are)

66. Complex Ions of the transition elements
Transition Metal Ion
Ni2+
Ligand
Ethanedioate
(this can form a 6 CN ion)

67. Complex Ions of the transition elements
Transition Metal Ion
Cu2+
Ligand
EDTA
(ethylenediaminetetracetate)
(this can form a 6 CN ion)

68. METAL AQUA IONS + OH-

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70. AQUA IONS + OH- [M(H2O)6]2+ + 2 OH- → [M(H2O)4(OH)2] + 2 H2O
M2+(aq) OH-(aq) → M(OH)2(s)
[Cu(H2O)6] OH- → [Cu(H2O)4(OH)2] H2O
Cu2+(aq) OH-(aq) → Cu(OH)2(s)
© A Jul-12

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72. AQUA IONS + OH- [M(H2O)6]2+ + 2 OH- → [M(H2O)4(OH)2] + 2 H2O
M2+(aq) OH-(aq) → M(OH)2(s)
[Co(H2O)6] OH- → [Co(H2O)4(OH)2] H2O
Co2+(aq) OH-(aq) → Co(OH)2(s)
© A Jul-12

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74. AQUA IONS + OH- [M(H2O)6]2+ + 2 OH- → [M(H2O)4(OH)2] + 2 H2O
M2+(aq) OH-(aq) → M(OH)2(s)
[Fe(H2O)6] OH- → [Fe(H2O)4(OH)2] H2O
Fe2+(aq) OH-(aq) → Fe(OH)2(s)
© A Jul-12

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76. AQUA IONS + OH- [M(H2O)6]3+ + 3 OH- → [M(H2O)3(OH)3] + 3 H2O
M3+(aq) OH-(aq) → M(OH)3(s)
[Al(H2O)6] OH- → [Al(H2O)3(OH)3] H2O
Al3+(aq) OH-(aq) → Al(OH)3(s)
© A Jul-12

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78. AQUA IONS + OH- [M(H2O)6]3+ + 3 OH- → [M(H2O)3(OH)3] + 3 H2O
M3+(aq) OH-(aq) → M(OH)3(s)
[Fe(H2O)6] OH- → [Fe(H2O)3(OH)3] H2O
Fe3+(aq) OH-(aq) → Fe(OH)3(s)
© A Jul-12

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80. AQUA IONS + OH- [M(H2O)6]3+ + 3 OH- → [M(H2O)3(OH)3] + 3 H2O
M3+(aq) OH-(aq) → M(OH)3(s)
[Cr(H2O)6] OH- → [Cr(H2O)3(OH)3] H2O
Cr3+(aq) OH-(aq) → Cr(OH)3(s)
© A Jul-12

81. METAL AQUA IONS + NH3
© A Jul-12

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83. AQUA IONS + NH3 [M(H2O)6]2+ + 2 NH3 → [M(H2O)4(OH)2] + 2 NH4+
NH3(aq) H+(aq) → NH4+(aq)
M2+(aq) OH-(aq) → M(OH)2
[Cu(H2O)6] NH3 → [Cu(H2O)4(OH)2] NH4+
NH3(aq) H+(aq) → NH4+(aq)
Cu2+(aq) OH-(aq) → Cu(OH)2
© A Jul-12

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85. AQUA IONS + NH3 [M(H2O)6]2+ + 2 NH3 → [M(H2O)4(OH)2] + 2 NH4+
NH3(aq) H+(aq) → NH4+(aq)
M2+(aq) OH-(aq) → M(OH)2
[Fe(H2O)6] NH3 → [Fe(H2O)4(OH)2] NH4+
NH3(aq) H+(aq) → NH4+(aq)
Fe2+(aq) OH-(aq) → Fe(OH)2
© A Jul-12

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87. AQUA IONS + NH3 [M(H2O)6]2+ + 2 NH3 → [M(H2O)4(OH)2] + 2 NH4+
NH3(aq) H+(aq) → NH4+(aq)
M2+(aq) OH-(aq) → M(OH)2
[Co(H2O)6] NH3 → [Co(H2O)4(OH)2] NH4+
NH3(aq) H+(aq) → NH4+(aq)
Co2+(aq) OH-(aq) → Co(OH)2
© A Jul-12

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89. AQUA IONS + NH3 [M(H2O)6]3+ + 3 NH3 → [M(H2O)3(OH)3] + 3 NH4+
NH3(aq) H+(aq) → NH4+(aq)
M3+(aq) OH-(aq) → M(OH)3
[Cr(H2O)6] NH3 → [Cr(H2O)3(OH)3] NH4+
NH3(aq) H+(aq) → NH4+(aq)
Cr3+(aq) OH-(aq) → Cr(OH)3
© A Jul-12

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91. AQUA IONS + NH3 [M(H2O)6]3+ + 3 NH3 → [M(H2O)3(OH)3] + 3 NH4+
NH3(aq) H+(aq) → NH4+(aq)
M3+(aq) OH-(aq) → M(OH)3
[Fe(H2O)6] NH3 → [Fe(H2O)3(OH)3] NH4+
NH3(aq) H+(aq) → NH4+(aq)
Fe3+(aq) OH-(aq) → Fe(OH)3
© A Jul-12

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93. AQUA IONS + NH3 [M(H2O)6]3+ + 3 NH3 → [M(H2O)3(OH)3] + 3 NH4+
NH3(aq) H+(aq) → NH4+(aq)
M3+(aq) OH-(aq) → M(OH)3
[Al(H2O)6] NH3 → [Al(H2O)3(OH)3] NH4+
NH3(aq) H+(aq) → NH4+(aq)
Al3+(aq) OH-(aq) → Al(OH)3
© A Jul-12

94. AMPHOTERIC NATURE Amphoteric = reacts with acids and bases
XS H+
XS OH-
[Cu(H2O)6]2+
[Cu(OH)2]
[Fe(H2O)6]2+
[Fe(OH)2]
[Co(H2O)6]2+
[Co(OH)2]
[Fe(H2O)6]3+
[Fe(OH)3]
[Cr(H2O)6]3+
[Cr(OH)3]
[Cr(OH)6]3-
[Al(H2O)6]3+
[Al(OH)3]
[Al(OH)4]-
© A Jul-12

95. AQUA IONS + XS OH- [Cr(H2O)3(OH)3]  [Cr(OH)6]3- + 3 OH- + 3 H2O
Cr(OH)3(s) → [Cr(OH)63-](aq)
+ 3 OH-(aq)
[Al(H2O)3(OH)3]  [Al(H2O)2(OH)4]-
+ OH H2O
Al(OH)3(s) → [Al(OH)4-](aq)
+ OH-(aq)
© A Jul-12

96. Ligand Substitution
Describe the process of ligand substitution and accompanying colour changes
Explain the biochemical importance of ligand substitution

97. Ligand Substitution What is ligand substution?
What does it usually cause?
What is partial ligand substitution?
Why does it happen?
Similarly sized ligands...
[Cu(H2O)6]2+ (aq) + 4NH3 (aq)
Different sized ligands...
[Cu(H2O)6]2+ (aq) + 4Cl- (aq)
[Co(H2O)6]2+ (aq) + 4Cl- (aq)

98. Partial Substitution of Ligands
What is partial ligand substitution? Why does it happen? [Cu(H2O)6]2+ (aq) + 4NH3 (aq) (Fe(H2O)6]3+ (aq) + SCN- (aq)

99. Haem and Haemoglobin

100. SUBSTITUTION BY Cl-
© A Jul-12

101. [Co(H2O)6]2+ + 4 Cl-  [CoCl4]2- + 6 H2O
© A Jul-12

102. SUBSTITUTION by larger ligands
Cl- bigger than O of H2O – only four Cl-’s fit around Mn+ H
Cl- O H
© A Jul-12

103. [Cu(H2O)6]2+ + 4 Cl- → [CuCl4]2- + 6 H2O
© A Jul-12

104. SUBSTITUTION BY NH3
© A Jul-12

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106. SUBSTITUTION by similar sized ligands
[Co(H2O)6] NH3 → [Co(NH3)6] H2O
air
[Co(NH3)6]2+
© A Jul-12

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108. SUBSTITUTION by similar sized ligands
[Co(H2O)6] NH3 → [Co(NH3)6] H2O
air
[Co(NH3)6]2+
[Cu(H2O)6] NH3 → [Cu(NH3)4(H2O)2] H2O
© A Jul-12

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110. SUBSTITUTION by similar sized ligands
[Co(H2O)6] NH3 → [Co(NH3)6] H2O
air
[Co(NH3)6]2+
[Cu(H2O)6] NH3 → [Cu(NH3)4(H2O)2] H2O
[Fe(H2O)6]2+
© A Jul-12

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112. SUBSTITUTION by similar sized ligands
[Co(H2O)6] NH3 → [Co(NH3)6] H2O
air
[Co(NH3)6]2+
[Cu(H2O)6] NH3 → [Cu(NH3)4(H2O)2] H2O
[Fe(H2O)6]2+
[Fe(H2O)6]3+
© A Jul-12

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114. SUBSTITUTION by similar sized ligands
[Co(H2O)6] NH3 → [Co(NH3)6] H2O
air
[Co(NH3)6]2+
[Cu(H2O)6] NH3 → [Cu(NH3)4(H2O)2] H2O
[Fe(H2O)6]2+
[Fe(H2O)6]3+
[Cr(H2O)6] NH3 → [Cr(NH3)6] H2O
© A Jul-12

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116. SUBSTITUTION by similar sized ligands
[Co(H2O)6] NH3 → [Co(NH3)6] H2O
air
[Co(NH3)6]2+
[Cu(H2O)6] NH3 → [Cu(NH3)4(H2O)2] H2O
[Fe(H2O)6]2+
[Fe(H2O)6]3+
[Cr(H2O)6] NH3 → [Cr(NH3)6] H2O
[Al(H2O)6]3+
© A Jul-12

117. Ligand Substitution Exam Questions
STARTER
Ligand Substitution Exam Questions

118. Iodine-Sodium Thiosulfate Titrations

119. Oxidise the iodide ions (from a redox reaction) to iodine.
Step 1
Oxidise the iodide ions (from a redox reaction) to iodine.
Measure a certain volume of Potassium Iodate (V) (KIO3) as the oxidising agent and add this to an excess of acidified Potassium Iodide (KI)
Iodate (V) ions oxidise I- to iodine; this produces a bright yellow solution.

120. Titrate the iodine solution with sodium thiosulfate (Na2S2O3)
Step 2
Titrate the iodine solution with sodium thiosulfate (Na2S2O3)
Take the solution from Step 1 and add to conical flask.
Add sodium thiosulfate (of a known concentration) from a burette until the colour becomes pale yellow.
Add 2cm3of starch to detect the presence of iodine (turns dark blue).
Continue titration until blue colour disappears
Record volume of sodium thiosulfate used.

121. Calculate the number of moles of iodine present
Step 3
Calculate the number of moles of iodine present
Calculate number of moles of sodium thiosulfate
Use reacting ratio from balanced equation.

122. Calculate the number of moles of the oxidising agent present
Step 4
Calculate the number of moles of the oxidising agent present
Use molar ratio of I2 : IO3- in step one to work out moles of potassium iodate (V)
Now using the volume, work out the concentration of the potassium iodate (V).

123. Find the concentration of the potassium iodate (V) solution.
Class Example
50cm3 of potassium iodate (V) solution was added to an excess of acidified potassium iodide.
The solution was then titrated against a mol dm-3 solution of sodium thiosulfate. 11.1cm3 of thiosulfate solution was required to react fully with the solution.
Find the concentration of the potassium iodate (V) solution.
NOTE: Potassium Iodate (V) may not always be used as the oxidising agent.