Transition metals

Question 1

What are the d-block transition metals?

Answer 1

Metals with an incomplete d sub shell in at least one of their ions.

Question 2

The filling of the d orbitals follows the aufbau principle, except…

Answer 2

Chromium and copper atoms.

Question 3

Why are chromium and copper exceptions?

Answer 3

Due to the special stability associated with the d subshell being half filled or filled.

Question 4

Zinc and scandium are not transition metals because…

Answer 4

They have full electron shells in all their ions.

Question 5

An element is said to be on a particular oxidation state when it…

Answer 5

has a specific oxidation number.

Question 6

Uncombined elements have an oxidation number of

Answer 6

0

Question 7

Ions containing single atoms have an oxidation number that is…

Answer 7

The same as the charge on the ion.

Question 8

Oxygen has an oxidation number of?

Answer 8

• 2, except in peroxides where it has an oxidation number of -1

Question 9

Hydrogen has an oxidation number of?

Answer 9

+1, except when in a metal hydride where it is -1.

Question 10

The sum of all the oxidation numbers of all the atoms in a neutral compound must add up to?

Answer 10

0

Question 11

The sum of all the oxidation numbers of all the atoms in a polyatomic ion must be…

Answer 11

Equal to the charge on the ion

Question 12

Compounds of the same transition metals in different oxidation states may have…

Answer 12

Different colours.

Question 13

What is oxidation?

Answer 13

Increase in oxidation number.

Question 14

What is reduction?

Answer 14

Decrease in oxidation number.

Question 15

Changes in oxidation number of transition metal ions can be used to…

Answer 15

Determine whether oxidation or reduction has occurred.

Question 16

Compounds containing metals in high oxidation states are often?

Answer 16

Oxidising agents.

Question 17

Compounds containing metals in low oxidation states are often?

Answer 17

Reducing agents.

Question 18

What are ligands?

Answer 18

Negative ions or molecules with non-binding pairs of electrons that they donate to the central metal atom or ion forming dative covalent bonds.

Question 19

Ligands can be classified as ?

Answer 19

Monodentate, bidentate up to hexadentate

Question 20

Monodentate ligands provide — electrons.

Answer 20

1

Question 21

Bidentate ligands provide — electrons.

Answer 21

2

Question 22

Hexadentate ligands complex in ——— ratio.

Answer 22

1:1

Question 23

What is the coordination number?

Answer 23

The total number of bonds from the ligands to the central transition metal.

Question 24

Coordination number and shape?
2 = ?

Answer 24

Linear

Question 25

Coordination number and shape? 4 = ?

Answer 25

Square planar or tetrahedral

Question 26

Coordination number and shape? 6 = ?

Answer 26

Octahedral

Question 27

Are the d orbitals degenerate in a complex of a transition metals?

Answer 27

No

Question 28

When does splitting of d orbitals to higher and lower energies occur?

Answer 28

When the electrons present in approaching ligands cause the electrons in the orbitals lying along the axes to be repelled.

Question 29

Strong field ligands?

Answer 29

Cause a large difference in energy between subsets of d orbitals.

Question 30

Weak field ligands?

Answer 30

Cause a small energy difference between subsets of d orbitals.

Question 31

Spectrochemical series

Answer 31

I⁻ < Br⁻ < Cl⁻ < F⁻ < OH⁻ < H₂O < NH₃ < en (ethylenediamine) < NO₂⁻ < CN⁻ < CO

Question 32

Colours of many transition metals can be explained in terms of?

Answer 32

d-d transitions.

Question 33

Light is absorbed when electrons…

Answer 33

Electrons in a lower energy d orbital are promoted to d orbitals of higher energy.

Question 34

If light of one colour is absorbed then…

Answer 34

The complementary colour is exhibited.

Question 35

Electrons transition to higher energy levels when

Answer 35

Energy corresponding to the UV or visible regions of the EM spectrum is absorbed.

Question 37

What does changing the ligand do?

Answer 37

Changes the split between d orbitals and therefore will change the colour.

Question 38

Transition metals and their complexes can act as?

Answer 38

Catalysts.

Question 39

Heterogenous catalysts?

Answer 39

Are in a different state to their reactants.

Question 40

Heterogenous catalysis (chat GPT)

Answer 40

Reactant molecules adsorb onto active sites, where unpaired d electrons or unfilled d orbitals in transition metals help form activated complexes. This provides an alternative pathway with lower activation energy, increasing the reaction rate.

Question 41

Homogenous catalysts?

Answer 41

In the same state as reactants.

Question 42

Homogenous catalysis (chat GPT)

Answer 42

Effective because they can change oxidation states, allowing them to form intermediate complexes with reactants. This stabilises transition states and provides an alternative reaction pathway with a lower activation energy.