Structure

Question 1

Giant structure

Answer 1

Regular repeating pattern of ions (or atoms) , known as a lattice. Each ion/atom is held in place by strong chemical bonds

Question 2

Simple structure

Answer 2

Small molecules which are strongly bonded inside the molecule and have different levels of intermolecular bonding between molecules

Question 3

Metals - MP+BP

Answer 3

HIGH
- Strong electrostatic forces between + ions and delocalised - electrons
- High amount of energy needed to break

Question 4

Metals - Conduction

Answer 4

CONDUCTIVE
- Free moving/mobile/delocalised electron can carry charge

Question 5

Metals - Solubility

Answer 5

INSOLUBLE
(In any solvent)

Question 6

Giant Ionic - MP+BP

Answer 6

HIGH
- Strong electrostatic attraction between oppositely charged ions
- High amount of energy needed to break

Question 7

Ionic - Conductivity

Answer 7

CONDUCTIVE if aqueous or molten
- Ions are mobile - carry charge

NOT CONDUCTIVE if solid
- Ions are fixed in place in lattice

Question 8

Giant Ionic - Solubility

Answer 8

SOLUBLE in POLAR solvent
Ex: H2O - δ+ H attracts anions
(O more electronegative/asymmetrical molecule) δ - O attracts cations
➡️ ions pulled away from lattice + dissociate (dissolves)

INSOLUBLE in NON polar solvent

Question 9

Giant covalent structures

Answer 9

Lattice of covalently bonded atoms, ‘macromolecular structure’

Question 10

Diamond

Answer 10

• 4 bonds per C ➡️ tetrahedral
• HARD, HIGH MP+BP - strong covalent bonds
• NOT conductive - localised e-
• INSOLUBLE in any solvent - attractions between solvent molecules never strong enough to overcome diamond covalent bonds

Question 11

Graphite

Answer 11

• 3 bonds per C (hexagonal sheets)
• HIGH MP+BP - strong covalent bonds between atoms
• CONDUCT - delocalised e- (3 bonds)
• INSOLUBLE - (same reason as diamond)
• Sheets bonded by weak temporary dipole dipole forces

Question 12

Graphene

Answer 12

• one atom thick layer of C atoms (pure form of C)
• Strong for low weight
• CONDUCTIVE - delocalised e- (potential use in electronics)

Question 13

Silicon

Answer 13

• HIGH MP+BP, hard - strong covalent bonds between atoms
  -NOT conductive - localised e-

Question 14

Physical properties of simple molecular structures determined by…

Answer 14

Bonding BETWEEN molecules

Question 15

3 types of intermolecular forces

Answer 15

1. Induced dipole dipole (London forces)
2. Permanent dipole dipole
3. Hydrogen bonding

Question 16

Iodine MP+BP

Answer 16

• LOW MP+BP - little energy needed to break the weak temporary induced dipole dipole attractions between molecules (sometimes sublimes at low temperature)

Question 17

Iodine conductivity

Answer 17

NOT conductive - no mobile ions/delocalised e-

Question 18

Iodine Solubility in Polar Solvents

Answer 18

Partially soluble
- simple structures unable to break H bonds in h2o + unable to make H bonds with polar water molecules ( solution turns light brown)

Question 19

Iodine solubility in non-polar solvents

Answer 19

Soluble
- simple structures are able to break weak induced dipole dipole between NP solvents
- simple structures are able to make induced dipole dipole bonds with NP solvents
(Solution turns purple)

Question 20

Structure of Silicon

Answer 20

Giant covalent

Question 21

What are ionic bonds always stronger than

Question 22

Shape of molecule determined by?

Answer 22

Shape of molecule is determined by electron repulsion theory as lone pairs repel more than bond pairs. Electron pairs repel as far as possible

Question 23

AgBr in water? Meaning?

Answer 23

AgBr is insoluble in h2o → ions remain fixed in giant lattice → cannot carry charge/conduct electricity in h2o