Chapter 24

Question 1

What are d-block elements?

Answer 1

All metals
High melting and boiling points
Conduct electricity when solid and liquid
Insoluble in water
Their highest energy electrons are found in the d subshell

Question 2

What is a transition element?

Answer 2

A d-block element that forms at least one ion with a partially filled d-orbital

Question 3

Why is scandium not a transition element?

Answer 3

Scandium will only form 3+ ions, which means the d sub-shell is empty

Question 4

Why is Zinc not a transition element?

Answer 4

Zinc only forms 2+ ions, which means the d sub-shell is completely full

Question 5

What are the properties of the transition elements?

Answer 5

They form compounds in which the transition element has different oxidation numbers.
They form coloured compounds.
The elements and their compounds can act as catalysts.

Question 6

How does a catalyst work?

Answer 6

By providing an alternate reaction pathway with a lower activation energy.

Question 7

What are the steps in heterogeneous catalysis?

Answer 7

Adsorption - the reactant molecules form weak bonds to the catalyst surface.
Bonds in the reactants break
Bonds in the products form
Products desorbs from the catalyst surface.

Question 8

What is a homogeneous catalyst?

Answer 8

A catalyst in the same physical state as the reactants

Question 9

What is a complex ion?

Answer 9

Formed when one or more molecules or negatively charged ions bond to a central metal ion. These molecules or negative ions are called ligands.

Question 10

What is a ligand?

Answer 10

A molecule or ion that donates a pair of electrons to a central metal ion to form a coordinate bond/dative covalent bond.

Question 11

What is the coordination number?

Answer 11

Indicates the number of coordinate bonds attached to the central metal ion. The shape of the ion depends on the coordination number.

Question 12

What is a monodentate ligand?

Answer 12

They donate one pair of electrons to the central metal atom.

Question 13

What are some common monodentate ligands and what are their charges?

Answer 13

Water = neutral
Ammonia = neutral
Chloride = 1-
Cyanide = 1-
Hydroxide = 1-

Question 14

What is a bidentate ligand?

Answer 14

They donate two pairs of electrons to the central atom, forming two coordinate bonds.

Question 15

What shape does a six coordinate complex take?

Answer 15

Octahedral
Bond angle = 90 degrees

Question 16

What shape does a 4 coordinate complex take?

Answer 16

Tetrahedral
Square planar

Question 17

What is the bond angle for a square planar complex?

Answer 17

90 degrees

Question 18

What shapes can form cis trans isomers?

Answer 18

Some square planar
Octahedral
Containing two different monodentate ligands

Question 19

What is optical isomerism?

Answer 19

Non superimposable mirror images of each other

Question 20

What complexes form optical isomers?

Answer 20

Some octahedral complexes that contain two or more bidentate ligands

Question 21

What is the role of Cis-platin?

Answer 21

Used in the treatment of cancer.
Forms a platinum complex inside the cell which binds to DNA and prevents it from replicating.
Trans-platin is inactive because of the geometry of the molecule.

Question 22

What is a precipitation reaction?

Answer 22

Two aqueous solutions containing ions react together to form an insoluble ionic solid, called a precipitate.

Question 23

What colour is the copper ion?

Answer 23

Blue

Question 24

What colour is copper hydroxide precipitate? (addition of NaOH)

Answer 24

Blue

Question 25

What colour is Fe(II)?

Answer 25

Pale green

Question 26

What colour is Iron(II) hydroxide? (Addition of NaOH)

Answer 26

Green

Question 27

What colour is Fe(III)?

Answer 27

Pale yellow

Question 28

What colour is Mn 2+ ?

Answer 28

Pale pink

Question 29

What colour is Iron(III) hydroxide? (Addition of NaOH)

Answer 29

Orange-Brown

Question 30

What colour is Mn(OH)2 ? (Addition of NaOH)

Answer 30

Light brown

Question 31

What colour is Cr 3+ ?

Answer 31

Violet

Question 32

What colour is Cr(OH)3 ? (Addition of NaOH)

Answer 32

Grey-Green

Question 33

What colour is Cr(OH)3 when excess NaOH is added?

Answer 33

Dark Green

Question 34

What is a ligand substitution reaction?

Answer 34

One ligand in a complex ion is replaced by another ligand

Question 35

What colour is Cu(NH3)?

Answer 35

Deep blue

Question 36

What colour is Cr(NH3)6 ?

Answer 36

Purple

Question 37

Why is Carbon monoxide toxic?

Answer 37

A ligand substitution reaction occurs when it is breathed in. Oxygen is replaced by the Carbon monoxide. Carbon monoxide binds more strongly than oxygen, which leads to oxygen transport being prevented.