How bonding and structure relate to properties (2.2) (M)

Question 1

What are the three states of matter?

Answer 1

solid, liquid and gas

Question 2

Which processes take place at the boiling point?

Answer 2

boiling and condensing

Question 3

Which processes take place at the melting point?

Answer 3

melting and freezing

Question 4

What is the simple model of states of matter? (with diagrams for each)

Answer 4

particles are represented by small solid spheres

Question 5

What is particle theory?

Answer 5

based on fact all matter is made up of tiny particles

It describes the movement of and average distance between particles

Question 6

What are the properties of a solid?

Answer 6

• have fixed shape an volume
• cannot be compressed
• least energetic

Question 7

What are the properties of a liquid

Answer 7

• have a fixed volume
• but can flow and take shape of container
• particles slide over each other
• occupy slightly more space than when solid (ice and water an exception)

Question 8

What are the properties of a gas?

Answer 8

• have no fixed volume or shape
• can be easily compressed
• particles move in all directions
• most energetic

Question 9

The amount of energy needed to change state from solid to liquid and from liquid to gas depends on what?

Answer 9

the strength of the forces between the particles of the substance

Question 10

What does the nature of the particles involved in changes of state depend on?

Answer 10

the type of bonding and the structure of the substance

Question 11

What do you call it when you go from a solid to gas?

Answer 11

sublimation

Question 12

What do you call it when you go from a gas to solid

Answer 12

deposition

Question 13

The stronger the forces between the particles the (…) the melting point and boiling point of the substance

Answer 13

higher

Question 14

2 needed

What are limitations of the simple model?

Answer 14

• in the model there are no forces
• all particles are represented as solid inelastic spheres (particles are not spheres and particles are mostly made up of empty spaces)

Question 15

In chemical equation, what are all the state symbols?

Answer 15

(s), (l) and (g), with (aq) for aqueous solutions

Question 16

How would you describe the structure of ionic compounds? (as well as the forces within this structure)

Answer 16

Ionic compounds have regular structures (giant ionic lattices) (of alternating positive and negative ions)

in which there are strong electrostatic forces of attraction in all directions between oppositely charged ions

these forces act in all directions in the lattice

Question 17

What are the melting and boiling points of ionic compounds like? Why is this?

Answer 17

These compounds have high melting points and high boiling points

because of the large amounts of energy needed to break the many strong bonds

Question 18

When can ionic compounds only conduct electricity? Explain why

Answer 18

When melted (molten) or dissolved in water

because the ions are free to move and so charge can flow and carry electrical charge

Question 19

Substances that consist of small molecules are usually which states of matter?

Answer 19

gases or liquids

Question 20

Substances that consist of small molecules have relatively (…) melting and boiling points

Answer 20

low

Question 21

Describe the intermolecular forces of a simple molecule

Answer 21

only weak forces between the molecules (intermolecular forces)

forces within molecules are strong (intramolecular forces) so it is hard to break down these molecules into separate reactants

Question 22

When the substance of simple molecules melts or boils, is it the covalent bonds or intermolecular forces that are overcome?

Answer 22

intermolecular forces, not the covalent bonds

Question 23

The intermolecular forces (…) with the size of the molecules, so larger molecules have (…) melting and boiling points

Answer 23

increase

higher

Question 24

Why do small molecules (covalent bonds) not conduct electricity?

Answer 24

because the molecules do not have an overall electric charge (no free electrons)

Question 25

Why are the bulk properties of simple molecular substances different from the properties of the elements/compounds that make them up?

Answer 25

intermolecular forces are weak compared with (strong) covalent bonds (atoms/molecules must act together)

Question 26

size

Polymers have (…) molecules. How are they described?

Answer 26

very large

repeating units/chains of molecules

Question 27

How are the atoms in the polymer molecules are linked to other atoms?

Answer 27

by strong covalent bonds

Question 28

strong vs weak

The intermolecular forces between polymer molecules are relatively (…)

Answer 28

strong

Question 29

What is the state at room temperature of polymers, due to the fact they have strong covalent bonds?

Answer 29

therefore these polymers are solids at room temperature

Question 30

What is the state of matter of giant covalent structures?

Answer 30

solids

Question 31

What is the melting point like of giant covalent structures?

Answer 31

The melting point is very high

Question 32

All of the atoms in giant covalent structures are linked to other atoms by…

Answer 32

strong covalent bonds

Question 33

What needs to happen for giant covalent structures to melt or boil?

Answer 33

the covalent bonds must be overcome

breaking apart the structure as all atoms are covalently bonded

Question 34

3 needed

What are examples of giant covalent structures?

Answer 34

Diamond and graphite (allotropes of carbon) and silicon dioxide (silica)

Question 35

What does a giant covalent structure look like?

Answer 35

example for diamond, other structures have different forms

Question 36

Metals have giant structures of atoms with (…) metallic bonding

Answer 36

strong

Question 37

What does metallic bonds being strong in metal atom mean for the melting/boiling points?

Answer 37

It means that most metals have high melting and boiling points

Question 38

How are atoms arranged in pure metals? What properties do they have because of this?

Answer 38

In pure metals, atoms are arranged in layers

this allows metals to be bent (ductile) and shaped (malleable)

Question 39

What is the problem with pure metals? What is the solution to this?

Answer 39

Pure metals are too soft for many uses

so are mixed with other metals to make alloys which are harder

Question 40

Why are alloys harder and stronger than metals?

Answer 40

In an alloy, there are atoms of different sizes.

Which distort the layers of atoms in the pure metal.

So layers can’t slide over each other

(A greater force is required the layers to slide over each other)

Question 41

What is stronger, pure gold (24 carat) or an alloy of gold (e.g. 18 carat)?

Answer 41

18 carat gold

Question 42

Why are metals good conductors of electricity?

Answer 42

because the delocalised electrons in the metal carry electrical charge through the metal

Question 43

Why are metals good conductors of thermal energy?

Answer 43

because energy is transferred by the delocalised electrons moving freely throughout the metal

Question 44

Explain, in terms of particles, why liquid iodine does not conduct electricity

Answer 44

Iodine has no delocalised electrons/ions

so cannot carry charge

Question 45

4 marks

Describe the structure and bonding in a thermosoftening polymer and explain why they felt when heated

Answer 45

Chains or large molecules

with intermolecular forces between chains

that are weak

and are easily overcome