Bonding

Question 1

What is the metallic bond

Answer 1

The electrostatic force of attraction between the positively charged ions and delocalised electrons.

Question 2

Describe the structure of a metallic bond

Answer 2

a giant lattice of positively charged ions in a sea of delocalised electrons.

Question 3

3 properties of a metallic bond

Answer 3

Electrical conductors
High mpts
Good thermal conductors

Question 4

Metals going across the period trends and why

Answer 4

Conductivity increases as there are more delocalised electrons.

Question 5

Metals going down a group trends and why

Answer 5

Mpts decrease as there are more occupied energy levels so the nucleus is further from the delocalised electrons.

Question 6

What does a single covalent bond consist of

Answer 6

one shared pair of electrons

Question 7

Define a pure covalent bond

Answer 7

when atoms of the same element form a covalent bond and the electrons are shared equally. This is because they have the same electronegativity.

Question 8

Define a polar covalent bond

Answer 8

When atoms of different elements share electrons. Atoms with different electronegativity values will share the pair of bonding electrons unequally, forming partial changes or a permanent dipole.

Question 9

In covalent bonds, what do the atom with the highest electronegativity do

Answer 9

will attract the bonding electrons closer towards it, therefore it turns slightly negative.

Question 10

In covalent bonds what atom attracts the electrons (turns negative)

Answer 10

Highest electronegativity

Question 11

Define the ionic bond

Answer 11

The ionic bond is the electrostatic attraction between positive and negative ions

Question 12

Ionic bond structure

Answer 12

3D crystal lattice where oppositely charged ions surround each other.

Question 13

What do elements far apart in the periodic table more likely to do

Answer 13

Form ionic rather than covalent bonds

Question 14

4 properties of ionic bonds

Answer 14

Don’t conduct as solid ions are not free to move
High mpts
Conduct in molten or solution
Many are soluble

Question 15

3 covalent networks

Answer 15

Boron
Carbon
Silicon

Question 16

4 covalent network properties

Answer 16

High mpts
Hard substances
Don’t conduct
Insoluble

Question 17

What state do van der Waals hold molecules

Answer 17

Liquid or solid

Question 18

What atoms/molecules do vdw hold

Answer 18

Discrete atoms (noble gases)
Discrete molecules (diatomics)

Question 19

Are VDW weak or strong

Answer 19

Weak

Question 20

2 types of VDW

Answer 20

Permanent dipole - permanent dipole
London Dispersion Forces

Question 21

What is LDF in monatomics

Answer 21

a force caused by an uneven distribution of the constantly moving electrons around the nucleus.

Question 22

What does the uneven distribution of electrons do to monatomics

Answer 22

causes one side of the atom to have a temporary dipole.

Question 23

What is a temporary dipole

Answer 23

a slightly + charge and one side a slightly - charge

Question 24

Why do monatomics have low mpt/bpt

Answer 24

Their LDF are weak

Question 25

How are LDF formed in covalent moleculars

Answer 25

formed as a result of electrostatic attractions between the temporary dipoles and induced dipoles caused by the movement of electrons

Question 26

What is a polar covalent bond

Answer 26

a covalent bond in which the atoms have a difference in electronegativity.

Question 27

What is a permanent dipole

Answer 27

the difference in charge in polar bonds

Question 28

What forces of attraction between polar molecules

Answer 28

PD-PD

Question 29

What does the spatial arrangement of polar covalent bonds do

Answer 29

sometimes result in the overall molecule becoming non polar.

Question 30

Are hydrocarbons polar or nonpolar

Answer 30

Nonpolar

Question 31

When does hydrogen bonding occur

Answer 31

Between very polar molecules

Question 32

3 very polar molecules

Answer 32

F, N and O

Question 33

What are hydrogen bonds

Answer 33

electrostatic forces of attraction between molecules that contain highly polar bonds.

Question 34

What does a greater number of e/gfm mean for bpt and why

Answer 34

increases it as it makes a greater the chance of temporary and induced dipoles forming and therefore creating stronger LDF of attraction, so it requires more energy to separate the molecules.

Question 35

Why sulfur has larger bpt than phosphorus

Answer 35

-Sulfur has an S8 discrete molecule structure and phosphorus has a P4 discrete molecule structure. -The sulfur molecule contains more electrons than phosphorus, so there are more temporary dipoles in sulfur. -This creates stronger LDF between the sulfur molecules, requiring more energy to separate them.

Question 36

Fullerne/C60 mpt

Answer 36

280

Question 37

Why would fullerene have a higher mpt than sulfur

Answer 37

it has more atoms present in the structure and therefore more LDF.

Question 38

Why compare substances with similar electrons or gfms

Answer 38

because LDF are acting on all molecules, so same gfms/e means that the strength of the LDF will be similar. Means a bpt difference can be attributed to another type of van der Waal

Question 39

Polar behaviour in electric fields

Answer 39

If a charged rod is held in a stream of liquid, the PD of polar liquids are attracted to the rod. (The flow changes)

Question 40

Viscosity meaning

Answer 40

The resistance to flow

Question 41

What molecules bonds are typically more viscous

Answer 41

polar or hydrogen bonds

Question 42

Polar and nonpolar miscibility

Answer 42

Very polar molecules do not mix with nonpolar molecules

Question 43

Explain polar and nonpolar immiscibility

Answer 43

The stronger hydrogen bonds between the water (polar) molecules cannot be broken by the nonpolar molecules as they have no charge to attract the polar molecules.

Question 44

Ionic compounds and polar covalent compounds miscibility

Answer 44

tend to be soluble in polar solvents such as water.

Question 45

Nonpolar molecular substances solubility

Answer 45

soluble in nonpolar substances.

Question 46

If charge is evenly distributed the bonding is...

Answer 46

Nonpolar

Question 47

If charge is unevenly distributed...

Answer 47

Polar

Question 48

What type of bond/force is not a van der waal

Answer 48

Covalent

Question 49

What type of bonds/forces are van der waals

Answer 49

Hydrogen LDF PD-PD

Question 50

What does hydrogen bonding do to a compound

Answer 50

The presence of O-H or N-H bonds will increase the solubility of a compound.

Question 51

Molecules with pd-pd polarity

Answer 51

Polar

Question 52

Permanent dipole (describe and compare to H bonding)

Answer 52

Due to a difference in electronegativity between the atoms involved in a covalent bond. PD-PD interactions are weaker than hydrogen bonding.