Structure And Bonding

Question 1

Describe pure covalent bonding

Answer 1

The shared pair of electrons is shared equally by the atoms in the molecule

Question 2

Describe polar covalent bonding

Answer 2

Unequal sharing of the bonded electrons. Which causes one atom to have a slightly negative charge, and the other having a slightly positive charge

Question 3

What do polar covalent bonds create?

Answer 3

Permanent dipoles

Question 4

Explain electronegativity

Answer 4

A numerical measurement on a scale of 0-4 (low to high) used to sssess an elements ability to attract bonded electrons

Question 5

What does the difference in electronegativity between atoms in a compound show?

Answer 5

An indication of the type of bonding present

Question 6

Describe the bonding continuum

Answer 6

The type of bonding changes gradually as the difference in electronegativity between atoms increases

Question 7

What is at either ends of the bonding continuum?

Answer 7

Ionic bonding at one end and pure covalent bonding at the other

Question 8

What is in the middle of the bonding continuum?

Answer 8

Polar covalent bonding

Question 9

What are intermolecular forces, and what is the other name they are known by?

Answer 9

Act between molecules, known as van der waals forces

Question 10

Name the three types of van der waals forces

Answer 10

London dispersion forces
Permanent dipole- permanent dipole interactions
Hydrogen bonding

Question 11

Describe London dispersion forces

Answer 11

Weak attractions between temporary dipoles in molecules, and are significant between non-polar molecules

Question 12

Describe permanent dipole-permanent dipole interactions.

Answer 12

Attractions between polar molecules which have permanent dipoles

Question 13

When will a molecule only be polar?

Answer 13

If one side of the molecule is slightly positive and the other is slightly negative

Question 14

When do hydrogen bonds form?

Answer 14

Form between highly polar molecules which have hydrogen bonded to the greatly electronegative elements

Question 15

What’s are the highly electronegative elements that allow for hydrogen bonds when they are bonded with hydrogen?

Answer 15

Fluorine
Oxygen
Nitrogen

Question 16

What does hydrogen bonds give compounds that is unusual?

Answer 16

Unusually high melting and boiling points

Question 17

Why do hydrogen bonding give unusually high melting and boiling points?

Answer 17

Because they are the strongest van der waals forces so they need more energy to separate the molecules

Question 18

An example of hydrogen bonding?

Answer 18

Water

Question 19

When water is cooled to 4 degreees Celsius what happens?

Answer 19

It expands and decreases density

Question 20

Why does water expand and decrease density when cooled?

Answer 20

The water molecules form a more open structure with increased hydrogen bonding

Question 21

Compounds with molecules and which have hydrogen bonds between them are more viscous than?

Answer 21

Compounds with molecules which have other intermolecular forces

Question 22

The polar nature of water makes it a good solvent for what type of compounds?

Answer 22

Ionic and polar covalent compounds

Question 23

Non-polar solvents can dissolve what type of substances?

Answer 23

Non-polar substances

Question 24

The molecules of polar covalent liquids which are miscible with water form hydrogen bonds with?

Answer 24

Water molecules

Question 25

What do polar covalent bonds create?

Answer 25

Permanent dipoles

Question 26

What does the difference in electronegativity between atoms in a compound show?

Answer 26

An indication of the type of bonding present

Question 27

What are intermolecular forces, and what is the other name they are known by?

Answer 27

Act between molecules, known as van der waals forces

Question 28

When will a molecule only be polar?

Answer 28

If one side of the molecule is slightly positive and the other is slightly negative

Question 29

What’s are the highly electronegative elements that allow for hydrogen bonds when they are bonded with hydrogen?

Answer 29

Fluorine
Oxygen
Nitrogen

Question 30

What does hydrogen bonds give compounds that is unusual?

Answer 30

Unusually high melting and boiling points

Question 31

Why do hydrogen bonding give unusually high melting and boiling points?

Answer 31

Because they are the strongest van der waals forces so they need more energy to separate the molecules

Question 32

Why does water expand and decrease density when cooled?

Answer 32

The water molecules form a more open structure with increased hydrogen bonding

Question 33

Compounds with molecules and which have hydrogen bonds between them are more viscous than?

Answer 33

Compounds with molecules which have other intermolecular forces

Question 34

Is water polar or non-polar?

Answer 34

Polar

Question 35

The polar nature of water makes it a good solvent for what type of compounds?

Answer 35

Ionic and polar covalent compounds

Question 36

Non-polar solvents can dissolve what type of substances?

Answer 36

Non-polar substances

Question 37

The molecules of polar covalent liquids which are miscible with water form hydrogen bonds with?

Answer 37

Water molecules