Inorganic Chemistry 3.2 - Transition Metals - Colour

Question 1

Transition metal ions are often ___.

Answer 1

coloured

Question 2

Transition metal ions appear coloured because they absorb…

Answer 2

the wavelength of light opposite their colour on the colour wheel

Question 3

Transition metal complexes are coloured because the ___ of their _-orbitals allows them to absorb specific ___ of light.

Answer 3

splitting, d-orbitals, wavelengths

Question 4

The d-orbitals of a transition metal split due to…

Answer 4

interactions between the electrons in the d-orbitals and electrons in the approaching ligand(s).

Question 5

What determines which d orbitals will be promoted above the rest?

Answer 5

the arrangement of ligands (linear, trigonal Planar ect)

Question 6

Why is this?

Answer 6

because the d orbitals that lie along the axis of an approaching ligand are promoted above the rest.

Question 7

The splitting of d orbitals to higher and lower energies occurs when the ___ present in approaching ___ cause the electrons in the orbitals lying along the axes to be ___.

Answer 7

electrons, ligands, repelled

Question 8

What do you call ligands that cause a large difference in energy between different d orbital subsets?

Answer 8

strong field ligands

Question 9

What are weak field ligands?

Answer 9

ligands that cause a small difference in energy between d orbital subsets

Question 10

What do you call the list which ranks ligands in order of their repulsion forces?

Answer 10

the spectrochemical series

Question 11

The specific d orbitals that are promoted to higher energy levels depends on the ___ of the ligands.

Answer 11

arrangement / number

Question 12

This is because the ligands are arranged to maximise ___, and will therefore approach along different ___ / at different ___, depending on how many there are.

Answer 12

separation, axes, angles

Question 13

When a ligand approaches a transition metal complex, ___ of the d orbitals are promoted, however…

Answer 13

all, however some are promoted higher than others (the ones on the axis of an approaching ligand)

Question 14

Light is absorbed when an electron is ___ from a low energy state to a ___ energy state. This is called a _- _ ____, and is used to explain colour in transition metals.

Answer 14

promoted, high.
d-d transition

Question 15

The greater the energy difference between the two levels, the ___ the frequency (and ___ the wavelength) of light absorbed whilst promoting an ___.

Answer 15

greater, smaller, electron

Question 16

If light of one colour is absorbed then the ___ colour is ___.

Answer 16

complementary, observed

Question 17

Complementary colours are ___ each other on the colour wheel (data booklet page: __).

Answer 17

opposite, 19

Question 18

Electrons transition to higher energy levels when energy corresponding to the ___ or ___ regions of the electromagnetic spectrum is absorbed.

Answer 18

Ultraviolet (UV), visible

Question 19

What could cause a transition metal ion to appear clear?
Why is this?

Answer 19

if it has a full 3d subshell - since there is no room for d-d transitions