Chapter 6

Question 1

Covalent bonds

Answer 1

The bonds between non-metallic atoms

Question 2

Chemical properties of covalent melcules

Answer 2

Low melting and boiling temperatures because they are gases
Poor conductors of electricity due to no mobile charge particles
Ignite easily
Gases or liquids at room temperature

Question 3

Covalent molecular element

Answer 3

Made up of identical atoms held together by covalent bonds including diatomic molecules

Question 4

Covalent molecular compounds

Answer 4

Any compounds containing covalent bonds

Question 5

Lone pairs

Answer 5

Two dots arranged as a pair

Question 6

Bonding pairs

Answer 6

Single dots (unpaired) are available for sharing

Question 7

Structural formula

Answer 7

When bonding pairs are replaced by a dash to make a diagram

Question 8

Different molecular shapes

Answer 8

Pyramidal
Tetrahedral
V-shaped
Linear
Planar

Question 9

VSEPR theory

Answer 9

Valence shell electron pair repulsion theory takes into account the spacing between the lone pairs and the bonding molecules to create the correct molecular shape

Question 10

Prefixes

Answer 10

1 - mono
2 - di
3 - tri
4 - tetra
5 - penta
6 - hexa
7 - hepta
8 - octa
9 - nona
10 - deca

Question 11

Rules for naming molecular compounds

Answer 11

1. The first element is named in full
2. second element is named as an anion with -ide
3. Prefixes are used to show how many each have

Question 12

The Pauling scale of electronegativities

Answer 12

1. Electronegativities increase from left to right within a period.
2. Electronegativities decrease from top to bottom within a group.
3. Metals generally have lower electronegativities than non-metals.

Question 13

Non polar covalent bonds

Answer 13

When two atoms of the similar elctronegativites are bonded together and share the elcetrons equally between them

Question 14

Polar covalent bonds

Answer 14

When two atoms of different electronegativities are bonded together and share the electrons unequally between the atoms

Question 15

Non-polar molecules

Answer 15

In non-polar molecules, the atoms have equal electronegativity and share electrons equally ot they are arranged in a way that cancels each other out

Question 16

Polar molecules

Answer 16

When the overall charge is polar because the bonds are polar and the molecule is arranged in a way that doesnt balance out

Question 17

Which molecular shapes are polar?

Answer 17

V-shaped or pyramidal molecules

Question 18

Which molecular shapes are non-polar?

Answer 18

Linear, planar and tetrahedral

Question 19

Intramolecular attractions

Answer 19

The bonds between the atom ie; covalent, metallic and ionic

Question 20

Intramolecular forces

Answer 20

The forces between molecules of a covalent molecular compound

Question 21

Different intramolecular forces

Answer 21

Dispersion
Dipole-Dipole
Hydrogen

Question 22

Dispersion forces

Answer 22

Occurs between all molecules
The weakest of the forces
The more electrons in the molecules the stronger the dispersion forces
The shape of the molecule affects the forces as a liquid state will hold the molecules together closer than gas

Question 23

Dipole-Dipole

Answer 23

Only occurs between polar molecules
Stronger force and causes higher boiling point
When the positive side of one molecule attracts the negative side of another molecule

Question 24

Hydrogen bonding

Answer 24

Occurs between two molecules in which hydrogen is bonded to nitrogen, oxygen or fluorine.
Strongest force
Because the hydrogen (positive end) is unshielded, the other dipole can approach far more closely. The closer the dipoles get, the stronger the bond that forms

Question 25

Properties of molecular compounds

Answer 25

Non-conductors because they are electrically neutral
Polar molecules dissolve in water because water is polar
Low mp/bp because of weak intermolecular forces
Soft and easily scratched