1.4 - Bonding

Question 1

Define Ionic Bond

Answer 1

An ionic bonding is the result of electron transfer from metals to non-metals. This results in the formation of positive and negative ions.
The ionic bonds are held together by the electrostatic force of attraction between the oppositely charged ions.

Question 2

Define Metallic Bond

Answer 2

In metal structures, metal atoms lose their outer electrons.
Metallic bonding is the electrostatic attraction between the sea of delocalised valence electrons and the nuclei of the positively charged metal ions. (Lattice formation)

Question 3

Define covalent Bond

Answer 3

Covalent bonding is the result of electron sharing between atoms to provide stability.
A covalent bond is the electrostatic force of attraction between between the negatively charged electron pair and the positively charged nuclei of the elements.

Question 4

What are the forces of attraction and repulsion in a covalent bond?

Answer 4

Attraction - The electron pair to the positively charged nuclei
Repulsion - Between the electron pair and between the nuclei

Question 5

What is a net balance?

Answer 5

Net balance is the overall attraction or repulsion.
In ionic crystals there is a balance
To form bonds attraction must outweigh repulsion

Question 6

Define coordinate bond
What is another name for this type of bond?

Answer 6

A covalent bond in which both of the shared electrons come from the same atom.
Dative Bond = Coordinate Bond

Question 7

Define electronegativity

Answer 7

The measure of an atom’s ability to attract electrons in a covalent bond.

Question 8

What atom are the electrons attracted toward?

Answer 8

The more electronegative atom

Question 9

What difference in electronegativity defines a Polar Covalent bond?

Answer 9

Between 0.3 - 1.8

Question 10

What difference in electronegativity defines a Pure Covalent bond?

Answer 10

Less than 0.3

Question 11

Define Dipole

Answer 11

A dipole is the slight charge an atom can get in a molecule. It occurs when electrons are drawn towards the more electronegative element, creating charge.

Question 12

What are the three intermolecular forces?

Answer 12

Dipole-dipole force
Induced dipole - Induced dipole force
Hydrogen bonds

Question 13

What can Dipole forces collectively be referred to as?

Answer 13

Van der Waal’s Forces

Question 14

Define Permanent Dipole

Answer 14

A permanent dipole occurs when one atom is more electronegative than the other within a molecule. Electron are drawn to the more electronegative creating a negative charge. The opposite side therefore takes up a positive charge.

Question 15

Define Dipole - Dipole Forces

Answer 15

Dipole - dipole forces are a force of attraction between oppositely charged dipoles on different molecules.
Dipoles are not always aligned due to the movement of molecules

Question 16

What factor effects dipole-dipole force?

Answer 16

The difference in electronegativity effects the strength of the attraction. The more electronegative one side is, the greater attraction of electrons. Therefore, stronger charge, therefore stronger force of attraction between oppositely charged dipoles between molecules.

Question 17

Define Induced Dipole

Answer 17

An induced dipole is a dipole that occurs in molecules with no permanent dipoles.
Electrons are still moving, therefore in particular moments electrons will not be distributed evenly across the two nuclei.
The difference in distribution of electrons in these moments creates a temporary dipole.

Question 18

Define induced dipole - induced dipole force?

Answer 18

An induced dipole is a dipole that occurs in molecules with no permanent dipoles.
Electrons are still moving, therefore in particular moments electrons will not be distributed evenly across the two nuclei.
The difference in distribution of electrons in these moments creates a temporary dipole.

The positive temporary dipole of the molecule,attracts electrons toward it from neighbouring molecules.
This creates an induced negative dipole in the neighbouring molecule.
This process repeats, the second dipole induces the third and so on
These temporary dipoles are created and destroyed constantly due to motion of electrons, but this process is so rapid that the attraction between molecules remains.

Question 20

Define Hydrogen Bond

Answer 20

Hydrogen bonds are intermolecular forces that occur when hydrogenbonds to the lone pairs in fluorine, oxygen or nitrogen

Question 21

Which is the strongest intermolecular force?

Answer 21

hydrogen bonds

Question 22

What increases the strength of induced dipole - induced dipole interactions?

Answer 22

The number of electrons - More electrons means greater fluctuation in movement around the nuclei.
This results in stronger temporary dipoles and therefore stronger forces between molecules.

Question 23

What makes a molecular substance soluble?

Answer 23

-It is soluble if it can form hydrogen bonds to water
-The bigger the molecule the less effective hydrogen bonding is.

Question 24

State VSEPR Theory

Answer 24

-The shape of the molecule is dependent upon the number of pairs of valence electrons in the central atom.
- Electrons - maximum distance minimum repulsion
Lone-pair / Lone pair repulsion is the greatest
Then lone-pair / bonding pair
Then bonding pair / bonding pair

Question 25

How do lone pairs affect bond angle?

Answer 25

Reduce by 2.5 degrees

Question 26

Shape and angle of 2 electrons pairs?

Answer 26

Linear - 180

Question 27

3 electron pairs

Answer 27

Trigonal Planar - 120

Question 28

4 electron pairs

Answer 28

Tetrahedral - 109.5

Question 29

3 electron pairs - 1 lone pair

Answer 29

Trigonal Pyramidal - 107

Question 30

2 electron pairs - 2 lone pairs

Answer 30

V-shaped

Question 31

5 electron pairs

Answer 31

Trigonal Bipyramidal - 90 & 120

Question 32

6 electron pairs

Answer 32

Octahedral - 90