Unit 5

Question 1

What is a transition metal?

Answer 1

A metal which doesn’t have completely filled d orbitals and can form stable ions

Question 2

What is different about D-block electron filling to most other elements?

Answer 2

The 4s orbital occupies a higher energy level than 3D so is the first lost

Question 3

Why are d-block elements more likely to show varied oxidation states?

Answer 3

Because they their 4S and 3D orbitals are close together in energy so the ionisation energies between 1st ie 2nd ie and third ie aren’t that different and the release of energy is much more than it takes to ionise

Question 4

What is a complex ion?

Answer 4

metal ion centre with a number of molecules surrounding it (ligands) they are usually attached by dative bonds

Question 5

What are ligands?

Answer 5

Molecules that bond to a metal, they usually have a lone pair that is used to form dative bonds with the metal

Question 6

What happens when a ligand bonds to a transition metal?

Answer 6

There are repulsions between electrons in the ligands and the electrons in d block. This raises the energy in some d orbitals causing them to split.

Question 7

Why are transition metal complexes coloured?

Answer 7

Ligands cause D-orbital splitting. When light is passed through it can be used to promote an electron between d orbitals. Energy of a particular colour will be absorbed to do the promoting, what isn’t absorbed is what colour we see

Question 8

Why do the d orbitals get split to different energy levels, why aren’t they degenerate?

Answer 8

The way the orbitals are orientated. Some are in between axis and the other 2 are along it. Lone pairs approach via the axis and so the two orbitals on the axis feel the most repulsion and are sent to a higher energy

Question 9

Why don’t non transition metal complexes have colours?

Answer 9

Colour is produced when energy is absorbed to promote electrons between d orbitals. Those without partially filled d orbitals cannot promote

Question 10

Give some properties of transition metals

Answer 10

Large charge to radius ratio
have high melting and boiling points
Show variable oxidation states

Question 11

What do you need to remember when filling d block orbitals?

Answer 11

4S is at a higher energy level in this case

Question 12

Why do d block elements have high boiling points?

Answer 12

Metallic bonding

Question 13

What are the d orbitals called within a plane? (within axis)

Answer 13

t2g

Question 14

What are d orbitals called along the axis?

Answer 14

eg

Question 15

Which d orbitals split to a higher energy?

Answer 15

eg

Question 16

Which d orbitals split to the lower energy?

Answer 16

t2g

Question 17

What is a monodentate ligand?

Answer 17

It donates one lone pair to the metal

Question 18

What colour will be produced by a small split in d orbitals

Answer 18

Green (less energy needed to promote between e levels)

Question 19

What colour will be produced by a large split in d orbitals?

Answer 19

Yellow (more energy needed to promote between e levels)

Question 20

How can you work out the energy gap between d orbitals?

Answer 20

e= hf
or
e= hc/wavelength

Question 21

What is low spin?

Answer 21

Electrons would rather pair together than separate as it costs more energy to promote them to next energy level Diamagnetic usually

Question 22

What is high spin

Answer 22

When electrons occupy orbitals singly, they have been given enough energy to overcome the energy difference in orbitals. Its paramagnetic usually

Question 23

what is a paramagnetic complex?

Answer 23

One with at least one unpaired electron. (one electron in an orbital instead of two)

Question 24

What is a complex called when all electrons are in pairs?

Answer 24

Diamagnetic

Question 25

Does the charge of a metal affect the crystal field splitting?

Answer 25

Yes