1. First-row d-block elements
Use sections 8 and 9 in your IB data booklet to compare the trend and the extent of the trend for atomic radius, first ionization energy and electronegativity between the 8 elements in period 3 and the 10 elements in the first row in the d-block.
What characteristic properties do the first row d-block elements have?
Compare and contrast their properties with potassium and calcium.
What are iron, nickel, manganese used for? Use an interactive periodic table.

2. First-row d-block elements
Variable oxidation states e.g. Fe2+ and Fe3+, Cu+ and Cu2+.
Form complex ions e.g. [Cu(NH3)4]2+
Form coloured compounds
Can act as catalysts
Show magnetic properties
Why?

3. Electron configuration

4. Common oxidation statesSc Ti V CR Mn Fe Co Ni Cu +1 +2 +3 +4 +5 +6 +7

5. Successive ionization energies
Compare the successive ionization energies of aluminium and vanadium
I.E. kJ mol -1 Al V 1
+578
+651 2
+1820
+1370 3
+2740
+2870 4
+11600
+4600 5
+14800
+6280

6. Transition metals/elements
A transition element is a d-block element that has an atom with a partially filled d-sub-level or that forms at least one stable cation that has a partially filled d-sub-level. As a result zinc is not considered a transition metal.

7. Complex ions

8. which can be shared with incomplete d-subshell of TM
TRANSITION METAL COMPLEXES
= central METAL ION (or atom) with
a FIXED number of MOLECULES or ANIONS
(called LIGANDS)
bonded to it by DATIVE (COORDINATE) bonds.
“COMPLEX”
 have no net charge
eg Ni(CO)4
“COMPLEX ION”
 have a net charge
eg [CuCl4] 2-
= anionic (-ve) complex
[Ni(H2O)6] 2+
= cationic (+ve) complex
Ligands have LONE PAIR(S)
which can be shared with incomplete d-subshell of TM
to form the coordinate bond(s), and hence the complex
eg [CuCl4] 2-
ligand is :Cl-
[Ni(H2O)6] 2+
ligand is H2O:

9. Complex ions monodentate and polydentate ligands

10. [Fe(H2O)6] metal ion = Fe2+ [Fe(H2O)5OH] metal ion = Fe3+
Determine the charge on each complex – where the charge of the ion is not mentioned also determine that
[Fe(H2O)6] metal ion = Fe2+
[Fe(H2O)5OH] metal ion = Fe3+
[CuCl4] metal ion = Cu2+
[Mn(H2O)6] SO4
[Co(NH3)6] (NO3)3
[NH4]2 [Fe(H2O)6] (SO4)2

11. Coloured compounds

12. Coloured complex ions

13. Colour wheel

14. Splitting d-sublevel in Cu2+

15. Coloured ions: factors affecting the colour

16. Colour complex ions

17. Challenge
Study the graphs and use them together with the colour wheel in your textbook to identify the colour shown by each complex ion.
Use the information below about each ligand to identify which graph shows the absorption of ligand A and B. Justify your answer:
Ligand A: more electronegative; holds electrons more closely to nucleus
Ligand B: less electronegative

18. Nature of ligand

19. Factors affecting colour or factors affecting split or Δ􏰈E
oxidation state of metal ion (i.e. number of 3d electrons, the more electrons the greater the repulsion)
nature of ligand (different repulsion/greater split e.g. by less electronegative atoms or ligands with greater charge density )
identity of metal ion/nuclear charge (attraction between nucleus and non-bonding pairs)
coordination number/number of ligands
shape of the complex ion

20. Spectrochemical series
See data booklet
The further up the series the greater the splitting in d-orbitals

21. Paramagnetic particles
Attracted weakly to a magnetic field.
Atoms or ions that contain unpaired d electrons behave like small magnets. Because of their spin electrons create a magnetic field that can align itself to an external electric or magnetic field when exposed to it; unpaired electrons can do this because they can spin in any direction – they create a net magnetic moment. The greater the number of unpaired electrons the more paramagnetic the material. The alignment is only temporary so they are only magnetic for a short period of time.
Examples of paramagnetic materials in the first row d-block:
atoms: all apart from Zn.
ions e.g. in compounds and complexes: e.g. Mg2+ has 5 unpaired electrons, Co2+ (3 unpaired electrons), Ni2+ (2 unpaired electrons), Fe2+ ( unpaired electrons).

22. Diamagnetic particles
Weakly repelled by external magnet
Have paired d-electrons and therefore create a magnetic field opposed or not aligned to an external field. The paired electrons cancel out each other’s magnetic field so there is no net magnetic moment in the atom or ion.
Examples of diamagnetic materials: Zn and Zn2+.

23. VARIABLE OXIDATION STATES OF IRON
REDUCTION
Brown
Fe3+
Fe2+
Pale green
OXIDATION
Reduction carried using excess granulated Zn
in dilute sulphuric acid
2Fe Zn  2Fe Zn2+
Excess zinc can be filtered off after reduction.
Oxidation can be carried out using excess H2O2(aq)
in dilute NaOH solution
2Fe H2O2  2Fe OH-
Iron(III) will form Fe(OH)3(s) in alkali
Converted to Fe3+(aq) by adding dil. acid
Fe(OH)3(s) + 3H+(aq)  Fe3+(aq) + 3H2O(l)

24. OXIDATION STATES OF CHROMIUM+6 +3 +2
CrO42-
Cr2O72-
= chromate(VI)
= dichromate(VI)
YELLOW
ORANGE
[Cr(OH)6]3-
[Cr(H2O)5(OH)]2+
[Cr(H2O)6]3+
= hexahydroxo-
chromium(III) ion
= pentaaquohydoxo-
chromium(III) ion
= hexaaquo-
chromium(III) ion
DARK GREEN
GREEN
RUBY
[Cr(H2O)6]2+
Exist in equilibrium in aqueous solution.
GREEN predominates.
Ruby in crystal or
at very low pH.
= hexaaquo-
chromium(II) ion
BLUE

25. OXIDATION STATES OF COBALT
+ Excess
NH3 +2 +3
[Co(H2O)6]2+(aq)
[Co(NH3)6]2+(aq)
PINK / RED
STRAW YELLOW
UNSTABLE!
OXIDATION
by heat with H2O2 in NaOH(aq)
OXIDATION
Quickly by H2O2 in NH3(aq) or slowly by O2 from air
Co(OH)3(s)
[Co(NH3)6]3+(aq)
DARK BROWN
DARK RED
STABLE

26. OXIDATION STATES OF COPPER+2 +1
[Cu(H2O)6]2+
[Cu(H2O)6] Cu
BLUE
BLUE
REDUCTION
by heating with copper in conc. HCl
DISPROPO RTIONATION
by adding dil. H2SO4
[CuCl2]-
CuCl(s)
COLOURLESS
WHITE
PRECIPITATION
by adding water
Note: Copper(I) oxide, Cu2O is the brick-red ppt. formed during a positive Fehling’s test.
CuCl(s)
WHITE

27. Match up correct explanation
Typical property
Match up correct explanation
A. Form coloured compounds
1. Variable oxidation states and empty orbitals
B. Can acts as a catalyst
2. Transition metal ions have high charge density
C. Variable oxidation states
3. Partially filled split 3d sublevel and d-to-d transitions
D. Can form complexes or complex ions with negative ions and molecules
4. 3d sublevel to be filled closer to nucleus than 4s sublevel. Increased shielding offsets increased nuclear charge. Similar atomic radii
E. Magnetic properties
5. Small differences in successive ionization energies
F. Similar first ionization energies
6. Unpaired 3 d electrons