Molecular Structure

Question 1

Definition of bond energy

Answer 1

The amount of energy absorbed to break a chemical bond, or energy released when a bond is formed

Question 2

Definition of bond length

Answer 2

The average distance between nuclei of 2 bonded atoms in a molecule

Question 3

What is molecular polarity determined by?

Answer 3

• polarity of bonds
• shape of the molecule

Question 4

Definition of electronegativity

Answer 4

The tendency of an atom to attract a shared electron pair during bonding

Question 5

Definition of dative or coordinate bonding

Answer 5

A coordinate bond is formed when one atom donates both electrons to form a bonding pair

Question 6

Meaning of VSEPR

Answer 6

Valence shell electron pair repulsion

Question 7

What is bond polarity determined by?

Answer 7

The electronegativity of the 2 atoms that form the bond

Question 8

Definition of a polar molecule

Answer 8

A molecule over which charge is distributed unevenly

An unequal distribution of electrons between two atoms during bonding

Question 9

Definition of a non-polar molecule

Answer 9

A molecule over which the charge is evenly distributed

An equal distribution of electrons between two atoms during bonding

Question 10

Definition of chemical bond

Answer 10

The net electrostatic force that two atoms sharing electrons exert on each other

Question 11

What is bond length determined by?

Answer 11

• atom size
• bond order
• difference in electronegativity

Question 12

What is bond strength determined by?

Answer 12

• bond length
• atom size
• bond order

Question 13

What group is the central atom of an angular shape in?

Answer 13

Group 6

Question 14

What group is the central atom of a trigonal planar in?

Answer 14

Group 3

Question 15

What group is the central atom of a trigonal pyramidal in?

Answer 15

Group 5

Question 16

What are the classes of bond polarity?

Answer 16

1. Non-polar covalent
2. Polar covalent
3. Ionic

Question 17

What are the two IMF types?

Answer 17

• Van der Waals forces
• hydrogen bonds

Question 18

List and explain the types of Van der Waals forces:

Answer 18

1. Dipole - dipole forces (2 polar molecules)
2. Dipole - induced dipole forces (polar + non-polar molecules)
3. Induced dipole - induced dipole / london forces (2 non-polar molecules)
4. Ion - dipole / ion - induced dipole

Question 19

VSEPR theory

Answer 19

A model used to predict the shape of a molecule based on the number of electron pairs that surround the central atom

Question 20

Non-ideal shapes

Answer 20

1. Angular
2. Bent
3. Trigonal pyramidal

Question 21

Ideal shapes

Answer 21

1. Linear
2. Trigonal planar
3. Tetrahedral