Chapter 4 - Bonding

Question 0

Charges of Ions

Answer 0

Most transition metals are 2+ (except Ag 1+)

Question 1

Ionic Bond

Answer 1

The electrostatic attraction between oppositely charged ions.

Question 2

Exceptions to Charges

Answer 2

Fe (+2, +3)
Cu (+1, +2)
Pb (+4, +2)

Question 3

Nitrate

Answer 3

NO3 -1

Question 4

Sulfate

Answer 4

SO4 -2

Question 5

Hydroxide

Answer 5

OH -

Question 6

Carbonate

Answer 6

CO3 -2

Question 7

Phosphate

Answer 7

PO4 -3

Question 8

Ammonium

Answer 8

NH4 +1

Question 9

Lewis Dot Diagram

Answer 9

A representation of the valence electrons and their behaviour.

Question 10

Covalent Bonds

Answer 10

Occur by the mutual attraction of nuclei for the shared electrons.

Question 11

Naming Covalent Bonds

Answer 11

1 - Mono
2 - Di
3 - Tri
4 - Tetra
5 - Penta
6 - Hexa
7 - Septa
8 - Octa
9 - Nona
10 - Deca

Question 12

Structural Diagram

Answer 12

Lewis diagram but only show bonded pairs.

Question 13

Length and Strength

Answer 13

Decreasing length = Increasing strength

Single bond —> Double bond —> Triple bond

Question 14

Rulebreakers

Answer 14

Be only needs 4 valence electrons.

B only needs 6 valence electrons.

Question 15

Dative Bonding

Answer 15

Anytime the central atom has more bonds than normal, the central atom is doing all the sharing.

Question 16

Macromolecules

Answer 16

Large/giant covalent molecules (network solids)

Question 17

VSEPR

Answer 17

Valence Shell Electron Pair Repulsion

1. Valence electrons act in pairs
2. Pairs repel
3. Unbonded pairs repel more
4. Electrons in multiple bonds act as a single “charge centre”

Question 18

4 Bonded Pairs

Answer 18

Electrons: Tetrahedral

Atoms: Tetrahedral

Question 19

4 Pairs (3 bonded)

Answer 19

Electrons: Tetrahedral

Atoms: Trigonal Pyramid

Question 20

4 Pairs (2 bonded)

Answer 20

Electrons: Tetrahedral

Atoms: Bent

Question 21

4 Pairs (1 bonded)

Answer 21

Electrons: Tetrahedral

Atoms: Linear

Question 22

2 Charge Centres

Answer 22

Electrons: Linear

Atoms: Linear

Question 23

3 Pairs

Answer 23

Electrons: Flat Triangle

Atoms: Planear Triangle

Question 24

3 Charge Centres

Answer 24

Electrons: Flat Triangle Atoms: Bent

Question 25

Polarity

Answer 25

HIGH: 1.7-3.3 (ionic bonds) MODERATE: 0.5-1.7 (polar bonds) LOW: 0-0.5 (diatomic bonds)

Question 26

Bond Dipole vs Molecular Dipole

Answer 26

Bond dipoles add to give you the overall molecular dipole.

Question 27

Bonding Capacity

Answer 27

``` H - 1 Cl (halogens) 1 O, S - 2 N, P - 3 C - 4 ```

Question 28

Intermolecular Bonds

Answer 28

Bonds between molecules are weaker than bonds in the molecule. The bond is broken when a substance melts, boils, evaporates or dissolves. The weaker the bond, the lower the bp, mp, and more volatile.

Question 29

Van der Waals'

Answer 29

Fluctuating dipole bond. The bigger the molecule, the more likely to happen. Present in non-polar substances. (weakest)

Question 30

Dipole-Dipole

Answer 30

Dipole bond between 2 polar substances (stronger)

Question 31

H-Bonding

Answer 31

Occurs when H is bonded to O, N, F (strongest)

Question 32

SiO2

Answer 32

Silicon dioxide - Very high melting

Question 33

Graphite

Answer 33

Sheets of carbon atoms (size of sheets determines hardness) Conducts electricity because double bond can move.

Question 34

Diamond

Answer 34

Very hard, high melting, doesn't conduct.

Question 35

Bucky Ball (C-60)

Answer 35

Closed cage of 60 carbons (12 pentagons, 20 hexagons) Good conductor Forms crystals

Question 36

Metallic Bonding

Answer 36

The electrostatic attraction between a lattice of positive ions and delicacies electrons.

Question 37

Metallic Ions

Answer 37

``` Good conductors (delocalized electrons are mobile) Very malleable (delocalized electrons move non-directionally) ```

Question 38

Trends in Melting Point

Answer 38

Na - Al are metallic bonds (strong) Si is a giant covalent bond (very strong) P4 - Ar are Van der Waals' (weak)

Question 39

Bond Strength

Answer 39

VDW < Dipole-Dipole < H-bonding < Metallic < Ionic/Covalent

Question 40

Conductivity

Answer 40

Depends on ability to have free moving charges (either electrons or ions)

Question 41

Solubility

Answer 41

Depends on ability to bind with solvent ("like dissolves like")

Question 42

Physical Properties: Ionic

Answer 42

Very high melting point Can conduct in liquid/aqueous, but not solid Very soluble in water because ions are attracted to different ends of water molecules

Question 43

Physical Properties: Covalent (VDW, DD, H-bond)

Answer 43

Very low melting point Poor conductors Can bond with water if polar or H-bond

Question 44

Physical Properties: Covalent

Answer 44

``` Very high melting point Not good conductor (diamond) unless bonds can move (graphite) Not soluble (non-polar) ```

Question 45

Physical Properties: Metallic

Answer 45

``` Greater the charge, higher the melting point Good conductor (liquid, solid) Not soluble ```