Transition metals

Question 1

Transition Metals

Answer 1

d block elements which can form one or more stable ions with incompletely filled d orbitals

Question 2

stereoisomerism

Answer 2

Same Mr

Different arrangements of atoms in space

Question 3

Ligand Substitution

Answer 3

One ligand is swapped for another

Question 4

cis/trans stereoisomerism

Answer 4

cis - same group on the same side
trans - same groups opposite sides
occurs in octahedral and square planar

Question 5

Copper (II) + Chlorine

Answer 5

ligand exchange
[Cu(H2O)6] 2+ + 4Cl- –> [CuCl4] 2- + 6H2O
octahedral –> tetrahedral
pale blue –> yellow

Question 6

Chromium (III) + NH3

Answer 6

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

Question 7

Copper (II) + NH3

Answer 7

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

Question 8

Iron (II) + NH3/NaOH

Answer 8

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

Question 9

Manganese (II) + NH3/NaOH

Answer 9

Precipitation Reaction
[Mn(H2O)6] 2+ –> [Mn(OH)2(H2O)4]
pale pink solution –> pale brown precipitate

Question 10

Iron (III) + NH3/NaOH

Answer 10

Precipitation Reaction
[Fe(H2O)6] 3+ –> [Fe(H2O)3(OH)3]
yellow solution –> rusty orange brown precipitate

Question 11

Cobalt (II) + NaOH

Answer 11

Precipitation Reaction
Co 2+ + 2OH- –> Co(OH)2
pink –> blue precipitate

Question 12

Coordination number

Answer 12

Number of dative bonds formed

Question 13

Bidentate ligand

Answer 13

A species which donated two pairs of electrons to form two dative bonds

Question 14

Cobalt (II) + Chlorine

Answer 14

ligand substitution
[Co(H2O)6]2+ + 4Cl- –> [CoCl4] 2- + 6H2O
pink –> blue

Question 15

How is cis platin used in cancer treatment

Answer 15

Binds to DNA
Replication cannot occur
Tumour cannot grow

Question 16

cisplatin

Answer 16

[Pt(Cl)2(NH3)2]

Question 17

Haemoglobin as complex ion

Answer 17

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

Question 18

Sc ion charge and electron configuration

Answer 18

Sc3+

1s2 2s2 2p6 3s2 3p6

Question 19

Zn ion charge and electron configuration

Answer 19

Zn2+

1s2 2s2 2p6 3s2 3p6 3d10

Question 20

Chromium (III) + NaOH

Answer 20

[Cr(H2O)6]3+ + 6OH- –> [Cr(OH)6]3- + 6H2O

pale purple –> dark green

Question 21

K2Cr2O7 + H2SO4

Answer 21

Cr2O7 2-

orange

Question 22

Cr3+ + hot alkaline H2O2 (oxidation)

Answer 22

CrO4 2-

yellow

Question 23

MnO4 -/Fe 2+ –> Mn 2+/Fe 3+

Answer 23

purple to pale pink (practically colourless)

MnO4 - –> Mn 2+

Question 24

I-/Fe 3+ –> I2/Fe 2+

Answer 24

Orange brown to brown

Fe3+ –> I2

Question 25

Cu2+ + I-

Answer 25

CuI (white precipitate)

I2 (brown solution)

Question 26

disporpotionation of Cu+ (Cu+ + H2SO4)

Answer 26

Cu (brown solid)

(CuSO4) blue solution