3.2.5 Transition metals (A-level only)

Question 1

Where do the d block elements sit on the periodic table?

Answer 1

In the middle of the periodic table

Question 2

What is a transition metal

Answer 2

A d-block element that can form at least one stable ion with a partially filled d-subshell

Question 3

What are two metals that are not transition metals?

Answer 3

Zinc and Scandium

Question 4

Why is scandium not a transition metal? [2]:

Answer 4

• Scandium only forms 1 stable ion of Sc³⁺

- It has an EMPTY d-subshell

Question 5

Why is zinc not a transition metal? [2]:

Answer 5

• It only forms one stable ion of Zn²⁺

- It has a FULL d-subshell

Question 6

Properties of transition metals [4]:

Answer 6

• Variable oxidation states
• Partially full d-subshell
• Coloured ions in solution
• Good catalysts

Question 7

Why do transition metals have variable oxidation states?

[2]:

Answer 7

• electrons sit in 4s and 3d energy levels which are very close
• so electrons are gained and lost using a similar amount of energy

Question 8

What does Iron(II) look like as an aqueous ion?

Answer 8

Green solution

Question 9

What does Copper(II) look like as an aqueous ion?

Answer 9

Blue solution

Question 10

What does Iron(III) look like as an aqueous ion?

Answer 10

Purple solution but may look brown/yellow cus of [Fe(H₂O)₅(OH)]²⁺₍ₐᵩ₎

Question 11

What is an example of a transition metal being a good catalyst? [2]:

Answer 11

• Iron in the Haber process

- Nickel or Platinum in hydrogenation

Question 12

What does Aluminium(III) look like as an aqueous ion?

Answer 12

Colourless solution

Question 13

What does Iron(II) look like due to the action of NaOH?

Answer 13

green precipitate that goes brown on standing in air

Question 14

What does Copper(II) look like due to the action of NaOH?

Answer 14

Blue precipitate

Question 15

What does Iron(III) look like due to the action of NaOH?

Answer 15

Brown precipitate / may look orangey brown

Question 16

What does Aluminium(III) look like due to the action of NaOH?

Answer 16

White Precipitate

Question 17

What does Iron(II) look like due to the action an excess of NaOH(aq)?

Answer 17

No further change

Question 18

What does Copper(II) look like due to the action an excess of NaOH(aq)?

Answer 18

No further change

Question 19

What does Iron(III) look like due to the action an excess of NaOH(aq)?

Answer 19

No further change

Question 20

What does Aluminium(III) look like due to the action an excess of NaOH(aq)?

Answer 20

Colourless solution

Question 21

What does Iron(II) look like due to the action of NH3(aq)?

Answer 21

green ppt goes brown

on standing in air

Question 22

What does Copper(II) look like due to the action of NH3(aq)?

Answer 22

blue ppt

Question 23

What does Iron(III) look like due to the action of NH3(aq)?

Answer 23

No further change

Question 24

What does Aluminium(III) look like due to the action of NH3(aq)?

Answer 24

No further change

Question 25

What does Iron(II) look like due to the action an excess of Na2CO3(aq)?

Answer 25

green ppt

Question 26

What does Copper(II) look like due to the action an excess of Na2CO3(aq)?

Answer 26

blue-green ppt

Question 27

What does Iron(IlI) look like due to the action an excess of Na2CO3(aq)? [3]:

Answer 27

• brown ppt
• (ppt may look orange-brown)
• and CO2 gas evolved

Question 28

What does Aluminium(IlI) look like due to the action an excess of Na2CO3(aq)? [2]:

Answer 28

• white ppt

- CO2 gas evolved

Question 29

Transition metal ions use…

Answer 29

vaccant, hybridised 4s, 4p, 4d orbitals to accept ligand coordinate bonds

Question 30

Ligand [definition]:

Answer 30

A species with a lone pair

Question 31

Coordinate bonds [explanation]:

Answer 31

Lone pair on ligand accepted by vacant orbitals

Question 32

How many lone pairs do transition metal ions accept? [2]:

Answer 32

• 4 lone pairs/ ligands

- 6 lone pairs/ ligands

Question 33

Monodentate =

Answer 33

1 lone pair per ligand so can only form one coordinate bond

Question 34

Examples of monodentate ligands [4]:

Answer 34

• Water
• NH3
• Cl-
• CN-

Question 35

Bidentate =

Answer 35

2 LPs per ligand so form 2 coordinate bonds

Question 36

Example of bidentate logo =

Answer 36

H₂NCH₂CH₂NH₂

Question 37

Multidentate =

Answer 37

Multiple lone pairs that can be used to make ligands/ multiple coordinate bonds per ligand

Question 38

Example of multidentate ligand =

Answer 38

EDTA⁴⁻

Question 39

What are the shapes of complex ions [4]:

Answer 39

• Octahedral
• Tetrahedral
• Square planar
• Linear

Question 40

Octahedral complex ions [3]:

Answer 40

• 6 coordinate bonds
• 90° bond angle
• Most common shape

Question 41

What is the coordination number of an octahedral ion?

Answer 41

6

Question 42

How do you work out the coordination number?

Answer 42

Count the no. of coordinate bonds

Question 43

Tetrahedral complex ions [3]:

Answer 43

• 4 coordinate bonds
• 109.5° bond angle
• Seen when ligands are large and charged

Question 44

Square planar complex ion [2]:

Answer 44

• 4 coordinate bonds

- 90° bond angle

Question 45

What is the coordinate number for a tetrahedral ion?

Answer 45

4

Question 46

What is an example of a square planar complex ion?

Answer 46

CISPLATIN

Question 47

What is the coordination number of a square planar ion?

Answer 47

4

Question 48

Linear complex ions [2]:

Answer 48

• 2 coordinate bonds

- 180° bond angle

Question 49

What is the coordination number for a linear complex ion?

Answer 49

2

Question 50

What is an example of a linear complex ion?

Answer 50

Tollen’s reagent