Transition Metals

Question 1

What is the colour of the solution formed by the [Fe(H2O)6]3+ complex

Answer 1

Purple Solution that appears brown.

Question 2

What is the colour of the solution formed by the [Fe(H2O)6]2+ complex

Answer 2

Green Solution

Question 3

What is the colour of the solution formed by the[Cu(H2O)6]3+ complex

Answer 3

Blue Solution

Question 4

What is the colour of the solution formed by the [Al(H2O)6]3+ complex

Answer 4

Colourless Solution

Question 5

What is the shape of [Fe(H2O)6]3+ complex

Answer 5

Octahedral

Question 6

What is the shape of [Fe(Cl)4]2- complex

Answer 6

tetrahedral

Question 7

Why is [Fe(Cl)4]2- tetrahedral

Answer 7

The Cl- ions are too big to fit more than 4 around a transition metals

Question 8

What shape of complex does Ag+ form?

Answer 8

Linear

Question 9

What is the formula of the platin complex?

Answer 9

Pt(NH3)2(Cl)2

Question 10

What is the shape of the cisplatin complex and what is the oxidation state of Pt in the complex

Answer 10

Square Planar - Pt2+

Question 11

State the two bidentate ligands

Answer 11

NH2CH2CH2NH2 and C2O42-

Question 12

Give the formula of the complex formed between Cu2+ and C2O42-

Answer 12

[Cu(C2O4)3]4-

Question 13

Draw the complex of Ni2+ and NH2CH2CH2NH2

Answer 13

Question 14

Which type of isomerism does the following complex display?

Answer 14

Cis -

Question 15

Which type of isomerism does the following complex display?

Answer 15

Trans isomerism

Question 16

Give an example of a multidentate ligand.

Answer 16

EDTA4-

Question 17

Define chelate effect.

Answer 17

The substitution of a monodentate ligand for a bi or multidentate ligand to form a more stable complex.

Question 18

What is the heterogeneous catalysist in the Contact process

Answer 18

V2O5

Question 19

What is the heterogeneous catalyst used in the Haber process

Answer 19

Solid Fe (Iron)

Question 20

Define autocayalysis

Answer 20

When a reaction is catalysed by a product of that reaction

Question 21

When balancing half equations what species should MnO4- be converted to?

Answer 21

Mn2+

Question 22

When balancing half equations what species should (C2O4)2- be converted to?

Answer 22

CO2

Question 23

When balancing half equations what species should (Cr2O7)2- be converted to?

Answer 23

Cr3+

Question 24

When balancing half equations what species should (S2O8)2- be converted to?

Answer 24

(SO4)2-

Question 25

Define heterogeneous catalysis

Answer 25

where the catalyst is in a different phase to the reactants

Question 26

Define homogeneous catalysis

Answer 26

where the catalyst is in the same phase as the reactants

Question 27

Describe the 3 steps of heterogeneous catalysis

Answer 27

(1)Reactants** adsorb** onto the surface of the catalyst on an active site.
(2) Reaction occurs on the surface of the catalyst
(3) Products desorb from the surface if the catalyst

Question 28

What happens to a catalyst when it is poisoned?

Answer 28

• Impurities can block the active sites.
• This prevents the reactants from adsorbing
• Purifying the reactants is the best way to prevent poisoning.

Question 29

What is the equation for the energy difference between d orbitals?

Answer 29

∆E = hf
Where ∆E = Change in Energy
h = Planck Constant 6.626x10-34
f = Frequency of Light (Hz)

∆E = hc/l
Where ∆E = Change in Energy
h = Planck Constan

Question 30

In terms of electrons, explain why an aqueous solution of cobalt(II) sulfate has a red colour.

Answer 30

(Blue) light is absorbed (from incident white light)

Due to electrons moving to higher levels/electrons excited

Red light (that) remains (is transmitted)

Question 31

With reference to electrons, explain why aqueous copper(II) ions are blue.

Answer 31

red light absorbed

d electrons excited / promoted
or d electrons move between levels / orbitals

the colour observed is the light transmitted

Question 32

Explain why complexes formed from transition metal ions are coloured.

Answer 32

M1 absorb (some) wavelengths/frequencies/colours/energies of (visible) light

M2 to promote/excite electrons in d-orbitals

M3 remaining wavelengths/frequencies/colours/energies of (visible) lighttransmitted (to give colour seen)