Clarifying terms and definitions

Question 1

What’s the difference between intermolecular and intramolecular attraction?

Answer 1

Intermolecular means between molecules, intramolecular means within molecules

Eg. the intramolecular bond between a single H2 molecule is strong, but the intermolecular bonds between a H2 molecule to another H2 molecule is very weak

Question 2

How do you describe bonds?

Answer 2

Ionic, covalent, metallic

Question 3

How do you describe structure?

Answer 3

Ionic:
- Giant lattice structure

Covalent:
- Simple molecular structure
- Giant molecular structure

Metallic:
- Lattice of positive ions surrounded by a sea of mobile electrons
- Giant metallic structure

Question 4

What is the relationship between forces and bond?

Answer 4

All bonds are forces but not all forces are bonds

Question 5

How do you describe forces (of attraction)?

Answer 5

• Electrostatic
• Intermolecular
• Intramolecular

Question 6

Define metallic bonds

Answer 6

Electrostatic forces of attraction between cations and electrons (not anions)

Question 7

Define ionic bonds

Answer 7

Electrostatic forces of attraction between cations and anions

Question 8

Define covalent bonds

Answer 8

• Electrostatic forces of attraction between shared electrons and the nucleus

Question 9

Why do metals conduct electricity?

Answer 9

Dependent on electrons (not ions)
- Delocalised electrons move and conduct electricity

Question 10

Why do ionic compounds conduct/not conduct electricity?

Answer 10

Dependent on ions (not electrons)
- No free-moving ions in solid state as ions are held in place by lattice structure
- When molten or dissolved in water, cations and anions are free to move/available to conduct electricity

Question 11

Why do giant molecular bonds conduct/not conduct electricity?

Answer 11

Dependent on electrons (not ions)

• When all outer electrons are used for bonding in a giant molecular structure, no free moving electrons can move through the structure to conduct electricity
  Eg. diamond-structured compounds
• If there’s at least one outer electron unused for bonding in a giant molecular structure, it is delocalised and will move freely along layers of atoms
• It is free moving and can conduct electricity

Question 12

Why don’t simple molecular structures conduct electricity?

Answer 12

Dependent on electrons (not ions)

They do not have free moving delocalised electrons to move freely within a structure to conduct electricity

Question 13

Usual state of metallic/covalent molecules

Answer 13

• Metals are monoatomic
• Non-metals are rarely monoatomic, usually diatomic
• Oxygen can be O3, sulfur exists as S8

Question 14

Charges of transition metals to remember

Answer 14

1+: silver

2+: Zinc

3+ Aluminium

Question 15

What’s the difference between sulfur dioxide, sulfur trioxide, sulfite and sulfate?

Answer 15

SO2, SO3, SO3(2-), SO4(2-)