AS.5 Bonding

Question 1

Metallic bonds

Answer 1

electrostatic attraction between positively charged ions and a sea of delocalised electrons

Question 2

diagram to represent metallic bonds

Answer 2

cations relative charge in a circle

sea of delocalised electrons represented by appropriate number of minuses

Question 3

giant

Answer 3

continous bonds

Question 4

lattice

Answer 4

regular and repeating pattern

Question 5

giant metallic lattice - melting and boiling point

Answer 5

very high

strong metallic bonds throughout structure

Question 6

giant metallic lattice - electrical conductivity

Answer 6

very high

delocalised electrons are free to move and carry charge

Question 7

giant metallic lattice - solubility

Answer 7

insoluble

some may react with water

Question 8

comparing the strength of metallic bonds

Answer 8

more e- and higher nucleur charge

stronger electrostatic attraction

stronger metallic bond

higher melting/boiling point

Question 9

ionic bonds

Answer 9

electrostatic attraction between two oppositely charged ions

Question 10

dot and cross ionic

Answer 10

square brackets with charge in top right corner

no dots or crosses on metal

appropriate dots and crosses on non-metal

number in front to indicate how many

Question 11

why do metals and non metals lose/gain electrons

Answer 11

full outer shell- more stable

Question 12

giant ionic lattice - melting and boiling point

Answer 12

high

strong ionic bonds throughout

Question 13

giant ionic lattice - electrical conductivity

Answer 13

solids do not conduct - ions are in fixed position - not mobile

molten/aqueous do conduct - ions are free to move

Question 14

Covalent bond

Answer 14

Strong electrostatic attraction between a shared pair of electrons and the nuclei of the 2 bonded atoms

Question 15

Dative covalent bonds

Answer 15

Both electrons in the covalent bond come from one of the atoms

The atom giving the electron pair must have a lone pair

The atom accepting the lone pair must have empty orbital space

Question 16

Why do molecules have a specific 3D shape

Answer 16

Result in minimum amount of repulsion between electron pairs

Question 17

Repulsion

Answer 17

MOST

Lone pair to lone pair

Lone pair to bond pair

Bond pair to bond pair

LEAST

Question 18

Linear

Answer 18

2-0-2

180*

Question 19

Trigonal planar

Answer 19

3-0-3

120*

Question 20

Tetrahedral

Answer 20

4-0-4

109.5*

Question 21

Pyramidal

Answer 21

3-1-4

107*

Question 22

Non-linear

Answer 22

2-2-4

104.5*

Lone pairs repel bonding pairs

Question 23

Octahedral

Answer 23

6-0-6

90*

Question 24

Each lone pair decreases angle by…

Answer 24

2.5*

Question 25

Electronegativity

Answer 25

Ability of an atom to attract the electron pair in a covalent bond

Question 26

Electronegativity increases as…..

Answer 26

Atomic radius decreases Bonding pair is closer to nucleus

Question 27

Polar molecules

Answer 27

Imbalanced electronegativity Has polar bonds Asymmetrical

Question 28

Intermolecular forces

Answer 28

Bonds between molecules in a simple covalent lattice

Question 29

London forces

Answer 29

Non-polar molecule Uneven distribution of electrons Creates temporary dipole Induces dipole in neighbouring molecule Two dipoles attract each other

Question 30

London force strength

Answer 30

1) no of electrons 2) surface area contact points

Question 31

Permanent dipole dipole forces

Answer 31

Polar molecules Dipoles attract each other Stronger than London forces because permanent

Question 32

Hydrogen bonds

Answer 32

H-F H-O H-N Strongest IMF Very polar Lone pair on F/O/N is very attracted to H

Question 33

Why ice is less dense than water

Answer 33

Each water molecule is able to form 4 hydrogen bonds as molecules are far more ordered in solid state Increase in number of hydrogen bonds that can be formed pushes molecules further apart Now adopt tetrahedral shape

Question 34

Simple molecular lattice - melting and boiling point

Answer 34

Low Breaking IMF which are much weaker than bonds

Question 35

Simple molecular lattice - electrical conductivity

Answer 35

Very low No mobile electrons or ions

Question 36

Simple molecular lattice - solubility

Answer 36

Polar dissolves in polar solvent Non polar dissolves in non polar solvent

Question 37

Giant covalent lattice vs simple covalent lattice

Answer 37

Giant has covalent bonds spread throughout so breaking bonds instead of IMF

Question 38

Graphite

Answer 38

Each carbon forms 3 covalent bonds Trigonal planar Hexagonal layers 1 delocalised electron between layers - London forces

Question 39

Diamond

Answer 39

Each carbon has 4 covalent bonds Tetrahedral SO2 has same structure

Question 40

Giant covalent lattice - melting and boiling point

Answer 40

Very high Very strong covalent bonds throughout

Question 41

Giant covalent lattice - electrical conductivity

Answer 41

Diamond - very low No delocalised electrons or mobile ions Graphite/graphene - very good Delocalised electrons

Question 42

Giant covalent lattice - solubility

Answer 42

Very low Can’t interact with water

Question 43

Graphene

Answer 43

Single layer of graphite Delocalised electron on surface - conduct

Question 44

Anamalous properties of water

Answer 44

Liquid denser than solid H bonds hold molecules apart in solid Strong H bonds Higher mp than expected

Question 45

Volatile

Answer 45

High bp = low volatility