3.4 Chemistry of the D block

Question 1

What is a transition metal?

Answer 1

A d block element that forms at least one ion with a partially filled d orbital

Question 2

Why are Cr and Cu exceptions to the electron configuration rules?

Answer 2

As their 4s electron pairs split to give a full and half full 3d orbital instead

Question 3

What is the electron configuration of Cu2+?

Answer 3

[Ar] 3d 9

Question 4

Why do transition metals form coloured compounds?`

Answer 4

D orbital splits and electrons move between gaps
energy gaps absorb and release energy causing colour

Question 5

What are the 2 wavelength equations?

Answer 5

E=hf
F=c/ λ

Question 6

How do liquids appear coloured?

Answer 6

They transmit coloured light

Question 7

What is a ligand?

Answer 7

A species with a lone pair of electrons that form a coordinate bond with a transition metal ion

Question 8

What are four examples of ligands?

Answer 8

NH3
H2O
OH-
Cl-

Question 9

What 3 factors affect compound colour?

Answer 9

Ligand type
oxidation state
metal ion or element type

Question 10

What is a complex ion

Answer 10

A species where ligands have formed coordinate binds with t.ms

Question 11

What are the characteristics of a hydrated ion?

Answer 11

Octahedral
90* and 180*
Bonds steming from Oxygen (4H2Os 2OHs)
coordinate bonds with O

Question 12

What determines the 2 isomers of hydrated ions?

Answer 12

The position of the OH group
180* between 2 or
90* between the 2

Question 13

What colour compound does Cu(H2O)6 + OH- form?

Answer 13

Cu(H2O)4(OH)2
Pale blue ppt

Question 14

What is a ligand exchange?

Answer 14

Solid formed due to a neutral charge

Question 15

X2+ + 2OH- —->

Answer 15

x(H2O)4(OH)2 + 2 H2O

Question 16

Fe2+ ligand colour change

Answer 16

Pale green to dirty green

Question 17

Cu2+ ligand colour change

Answer 17

Blue to Pale blue

Question 18

Fe3+ ligand colour change

Answer 18

Yellow to Rust brown

Question 19

Co2+ ligand colour change

Answer 19

Pink to blue

Question 20

Cr3+ ligand colour change

Answer 20

Green to grey green

Question 21

Which ligand exchange reaction is amphoteric?

Answer 21

Cr3+ forms [Cr(OH)6]3-

Question 22

What is the descriptor of transition metal ppts?

Answer 22

Gelatinous

Question 23

What colour is the NH3 cu ligand?

Answer 23

Royal blue

Question 24

What colour is the Cl Cu ligand?

Answer 24

Yellow/green

Question 25

What shape is the the Cl Cu ligand?

Answer 25

Tetrahedral

Question 26

What is a catalyst?

Answer 26

A substance that increases the rate of a reaction, by finding an alternative mechanism pathway and lowering the activation energy

Question 27

What does Heterogeneous mean?

Answer 27

Different state to the reactants

Question 28

What does Homogeneous mean?

Answer 28

Same state as the reactants

Question 29

What is an example of a heterogeneous catalyst?

Answer 29

Alkene(L) to Alkane(S)
nickel catalyst (S)

Question 30

What is the Harbour process used for?

Answer 30

Agriculture and pharmaceuticals

Question 31

What is the equation of the harbour process?

Answer 31

3H2 (g) + N2 (g) <—> 2NH3 (g)

Question 32

What is the catalyst of the Harbour process?

Answer 32

Fe (s)

Question 33

What is the equation of the Contact process?

Answer 33

SO2 + O3 <—> SO3

Question 34

What is the catalyst of the Contact process?

Answer 34

V2O5
Vanadium pentoxide

Question 35

What is the equation of the decomposition of hydrogen peroxide?

Answer 35

2H2O2 —-> 2H2O (l) + O2 (g)

Question 36

What is the catalyst for the decomposition of H2O2?

Answer 36

MnO2

Question 37

Why do T.M make good catalysts?

Answer 37

variable oxidation states
partially filled orbitals so readily accept e-

Question 38

What are the 3 steps of the mechanism of heterogeneous catalysts?

Answer 38

1. Absorption (weakening bonds in molecules)
2. Atoms rearrange (atoms attach to surface of catalyst, builds up and rearranges)
3. Desorption (releasing of molecules creates room for more