Transition metals Flashcards
Transition Metals
d block elements which can form one or more stable ions with incompletely filled d orbitals
stereoisomerism
Same Mr
Different arrangements of atoms in space
Ligand Substitution
One ligand is swapped for another
cis/trans stereoisomerism
cis - same group on the same side
trans - same groups opposite sides
occurs in octahedral and square planar
Copper (II) + Chlorine
ligand exchange
[Cu(H2O)6] 2+ + 4Cl- –> [CuCl4] 2- + 6H2O
octahedral –> tetrahedral
pale blue –> yellow
Chromium (III) + NH3
ligand exchange
[Cr(H2O)6] 3+ + 6NH3 –> [Cr(NH3)6] 3+ + 6H2O
violet (pale purple) –> purple
Cr(OH)3 formed as an intermediate, grey-green precipitate
Copper (II) + NH3
ligand exchange
little: [Cu(H2O)6] 2+ + 2NH3 –> [Cu(H2O)4(OH)2] + 2NH4 +
blue solution –> pale blue precipitate
excess: [Cu(H2O)4(OH)2] + 4NH3 –> [Cu(H2O)2(NH3)4] 2+ + 2H2O + 2OH-
blue precipitate –> dark blue solution
Iron (II) + NH3/NaOH
Precipitation reaction
[Fe(H2O)6] 2+ –> [Fe(OH)2(H2O)4]
pale Green solution –> dark green precipitate
green precipitate flows to top and is oxidised to rust brown
Manganese (II) + NH3/NaOH
Precipitation Reaction
[Mn(H2O)6] 2+ –> [Mn(OH)2(H2O)4]
pale pink solution –> pale brown precipitate
Iron (III) + NH3/NaOH
Precipitation Reaction
[Fe(H2O)6] 3+ –> [Fe(H2O)3(OH)3]
yellow solution –> rusty orange brown precipitate
Cobalt (II) + NaOH
Precipitation Reaction
Co 2+ + 2OH- –> Co(OH)2
pink –> blue precipitate
Coordination number
Number of dative bonds formed
Bidentate ligand
A species which donated two pairs of electrons to form two dative bonds
Cobalt (II) + Chlorine
ligand substitution
[Co(H2O)6]2+ + 4Cl- –> [CoCl4] 2- + 6H2O
pink –> blue
How is cis platin used in cancer treatment
Binds to DNA
Replication cannot occur
Tumour cannot grow
cisplatin
[Pt(Cl)2(NH3)2]
Haemoglobin as complex ion
O2 binds to Fe (II) in haem group
If CO present CO binds instead of O2
binds more strongly than O2 creating more stable molecule
O2 cannot bind and aerobic respiration cannot occur
Sc ion charge and electron configuration
Sc3+
1s2 2s2 2p6 3s2 3p6
Zn ion charge and electron configuration
Zn2+
1s2 2s2 2p6 3s2 3p6 3d10
Chromium (III) + NaOH
[Cr(H2O)6]3+ + 6OH- –> [Cr(OH)6]3- + 6H2O
pale purple –> dark green
K2Cr2O7 + H2SO4
Cr2O7 2-
orange
Cr3+ + hot alkaline H2O2 (oxidation)
CrO4 2-
yellow
MnO4 -/Fe 2+ –> Mn 2+/Fe 3+
purple to pale pink (practically colourless)
MnO4 - –> Mn 2+
I-/Fe 3+ –> I2/Fe 2+
Orange brown to brown
Fe3+ –> I2
Cu2+ + I-
CuI (white precipitate)
I2 (brown solution)
disporpotionation of Cu+ (Cu+ + H2SO4)
Cu (brown solid)
(CuSO4) blue solution
