Atomic structure, types of bondings

Question 1

The reason why the boiling point of nitrogen is very low even though the bond between the atoms in a nitrogen molecule is very strong is [2]

Answer 1

Weak intermolecular and low amount of energy required to break bonds between molecules; [1 mark]
covalent bonds don’t break [1 mark]

Question 2

The difference in electrical conductivity between solid and liquid strontium chloride is

Answer 2

Ions cannot move in solid
OR
Ions can move in liquid; [1 mark]

Question 3

The difference in electrical conductivity between liquid strontium chloride and liquid sulfur chloride is

Answer 3

No ions in sulfur chloride
OR
Sulfur chloride is covalent
OR
Sulfur chloride only contains molecules
OR
Only strontium chloride has ions; [1 mark]

Question 4

Diamond is an example of

Answer 4

Giant covalent structure

Question 5

Give an example of an ionic compound

Answer 5

Sodium chloride

Question 6

Explain how simple covalent molecules have low melting and boiling points even though covalent bonds are strong [3]

Answer 6

1) Intermolecular forces that hold covalent molecules together
2) Intermolecular force is weak
3) Requires low energy to break

Question 7

What is an ionic bonding?

Answer 7

Metal atom will transfer electrons to non metal so both can form a full outershell for stability

Question 8

Why do diamond and graphite have high melting point [3]

Answer 8

1) It has billions of covalent bonds, it is 1 molecule for the entire structure.
2) Every carbon is bonded 4 times
3) No intermolecular forces

Question 9

Why is graphite slippery

Answer 9

Weak forces of attraction between layers so it can slide over each other

Question 10

What is the formation of positive ions called

Answer 10

Cation

Question 11

Formation of negative ions

Answer 11

Anion

Question 12

Define ionic bond

Answer 12

Strong electrostatic attraction between oppositely charged ions

Question 13

5 properties of ionic compound

Answer 13

1) High melting & boiling point
2) good electrical conductivity when aqueous or
molten and poor when solid
3) Hard; [1 mark]
4) Soluble in water / insoluble in organic solvents; [1 mark]
5) Brittle

Question 14

Draw the giant lattice of ionic compound

Answer 14

regular arrangement of
alternating positive and negative ions

Question 15

Ionic bonds are formed between

Answer 15

Metals & non-metals

Question 15

Explain why ionic structures have high melting points and boiling points [2]

Answer 15

Lots of strong electrostatic forces,
requires lots of energy to break

Question 15

Explain why ionic structures have good electrical conductivity when aqueous or
molten but poor when solid [2]

Answer 15

1) Ions can flow around freely in an aqueous state which conducts electricity
2) Charges are immobile in solid state

Question 16

Covalent bonding

Answer 16

When non-metals & non metals react and overlap pairs of electrons to get a full outershell

Question 17

3 properties of covalent bonded compounds

Answer 17

1) Low melting & boiling point
2) Poor electrical conductivity
3) Covalent compounds are not soluble in water

Question 18

Explain why covalent structures have poor electrical conductivity points [2]

Answer 18

1) There are no charged molecules flowing around
2) There are no free electrons

Question 19

Negative ion

Answer 19

Anion

Question 20

Positive ion

Answer 20

Cation

Question 21

metallc bonding

Answer 21

the electrostatic attraction between the positive ions in a giant metallic lattice and a ‘sea’ of delocalised electron

Question 22

3 properties of metallic bonding

Answer 22

1) good electrical conductivity
2) malleable and ductile
3) High melting and boiling points

Question 23

Why are metallic bonding strong

Answer 23

Strong attraction between the positive metal ions and sea of delocalised electrons

Question 24

Explain why metallic bonding have good electrical conductivity

Answer 24

delocalised electrons carry charge and move around structure freely

Question 25

Explain why metallic bonding are malleable and ductile

Answer 25

Pure metals are arranged in layers and are the same size 2) Layers slide past each other when a force is extered

Question 26

Describe diamond structure [3]

Answer 26

1) 1 carbon is bonded 4 more times 2) All covalent bonds are strong and identical 3) No intermolecular forces

Question 27

Describe graphite structure

Answer 27

1) 1 carbon is bonded 3 more times that form layers of hexagons leaving 1 delocalised electron per carbon atom 2) Covalent bonds between layers are strong 3) Layers are attracted to each other by weak intermolecular forces

Question 28

Why is graphite used as a lubricant

Answer 28

Layers can slide past each other

Question 29

Why is graphite used as a electrode [3]

Answer 29

1) good conductor of electricity 2) chemically stable 3) Have high melting & boiling point

Question 30

Why is diamond used as a cutting tool

Answer 30

Diamond have lots of strong covalent bonds making it a hard material that can cut through other materials

Question 31

Describe the giant covalent structure of silicon(IV) oxide, SiO2 [2]

Answer 31

1) Each Silicon atom forms covalent bonds with 4 Oxygen atoms and each Oxygen atom in turn forms covalent bonds with 2 Silicon atoms 2) tetrahedral arrangement

Question 32

Describe the similarity in properties between diamond and silicon(IV) oxide, related to their structures [4]

Answer 32

1) both have tetrahedral arrangement 2) SiO2 has lots of very strong covalent bonds and no intermolecular forces like diamond 3) both have high boiling & melting points 4) Both are hard 5) Silicion oxide can form acidic oxide

Question 33

Define lattice

Answer 33

A repeating pattern of particles

Question 34

Define electrostatic forces

Answer 34

he attractive or repulsive force between two electrically charged objects.

Question 35

Ammonium

Answer 35

NH4

Question 36

Hydroxide

Answer 36

OH

Question 37

Nitrate

Answer 37

NO3

Question 38

Sulfate

Answer 38

SO4

Question 39

Carbonate

Answer 39

CO3

Question 40

Hydrgoen carbonate

Answer 40

HCO3