Chapter 6 - Shapes of molecules and intermolecular forces

Question 1

What shape would a molecule with one lone pair and three bonded pairs be?

Answer 1

Pyramidal

Question 2

What shape would a molecule with two lone pair and two bonded pairs be?

Answer 2

Non-linear

Question 3

What shape would a molecule with 2 electron regions be?

Answer 3

Linear

Question 4

What shape would a molecule with 3 electron regions be?

Answer 4

Trigonal planar

Question 5

What shape would a molecule with 4 electron regions be?

Answer 5

Tetrahedral

Question 6

What shape would a molecule with 5 electron regions be?

Answer 6

Octahedral

Question 7

How much closer to lone pairs push bonds together?

Answer 7

2.5 degrees

Question 8

What is electronegativity?

Answer 8

The ability of an atom to attract the bonding electrons in the covalent bond.

Question 9

What is used to measure electronegativity?

Answer 9

The Pauling scale.

Question 10

What is the bond type if the electronegativity difference is 0?

Answer 10

Covalent.

Question 11

What is the bond type if the electronegativity difference is 0 to 1.8?

Answer 11

Polar covalent.

Question 12

What is the bond type if the electronegativity difference is greater than 1.8?

Answer 12

Ionic.

Question 13

What are two points about non-polar bonds?

Answer 13

The bonded electron pair is shared equally between atoms and they have the same/similar electronegativity.

Question 14

Describe a polar bond.

Answer 14

A bond where the bonded electron pair is shared unequally between the bonded atoms.

Question 15

What are the three types of intermolecular force?

Answer 15

• Induced dipole-dipole interactions(London forces)
• Permanent dipole-dipole interactions
• Hydrogen bonding

Question 16

Summarise induced dipole-dipole interactions (London forces).

Answer 16

The movement of electrons produces a changing dipole in a molecule which induces dipoles on neighbouring molecules.

Question 17

Are non-polar simple molecular substances soluble in non-polar solvents?

Answer 17

Yes.

Question 18

Are non-polar simple molecular substances soluble in polar solvents?

Answer 18

No.

Question 19

Are polar simple molecular substances soluble in polar solvents?

Answer 19

Yes.

Question 20

Why can’t simple molecular substances conduct electricity?

Answer 20

There are no mobile charged particles in the simple molecular structures so there’s nothing to complete an electrical circuit.

Question 21

Hydrogen bonding occurs between hydrogen and what three other elements?

Answer 21

Nitrogen (N), oxygen (O) and Flourine (F).

Question 22

Why does ice float?

Answer 22

It is a rigid structure which is less dense than water as the molecules are held further apart.