Intermolecular Forces

Question 1

Name the three types of intermolecular force

Answer 1

1. London force
2. Permanent dipole-dipole interacitons
3. Hydrogen bonds

Question 2

Name the weakest type of intermolecular force

Answer 2

London Forces

Question 3

London forces are caused by the [blank] movement of electrons

fill in th blank

Answer 3

random

Question 4

Do all molecules experience London Forces?

Answer 4

Yes

Question 5

What determines the strength of London forces?

Answer 5

1.The number of electrons in the molecule.

The more electrons=the stronger the London forces

2. Surface points of contact

The more points of contact, the stronger the London Forces

Question 6

What is the only type of molecule that has permanent dipole-dipole interactions?

Answer 6

Polar molecules

if this polarity of the molecule is cancelled bc/ it’s symmetrical, it is no longer polar and so does not have any permanent dipole dipole interactions

Question 7

Which 3 elements does Hydrogen bond to in Hydrogen bonding

Answer 7

Hydrogen bonds to the lone pairs of electrons on Nigtrogen, Oxygen and Fluorine, when in -NH, -OH or -HF

Question 8

What properties does hydrogen bonding give to water?

Answer 8

1. Gives water a high melting and boiling point
2. Makes ice less dense than water

Question 9

Why does water have a high boiling point?

Answer 9

1. most simple molecular compounds have low boilng points because they have only london forces
2. Water has both london forces and hydrogen bonds
3. Hydrogen bonds are stronger than London forces
4. A significantly greater amount of energy is required to overcome Hydrogen bonds, so more energy is required than is expected of london forces
5. This gives water a higer melting and boiling point

1) state the intermolecular forces present
2) Compare their strength
3) Say which needs more enrgy to overcome
4) Therefore which has the higher melting/boiling point

Question 10

Why is ice less dense than water?

Answer 10

When water freezes, the hydrogen bonds hold the water molecules further apaprt than they are in liquid form in rigid structure, this makes ice less dense than water

Question 11

What is a simple molecular molecule

Answer 11

A small covalent molecule with a fixed number of atoms attracted by intermolecular forces

Question 12

Explain the solubility of simple molecular compounds

Answer 12

Non-polar simple molecular compounds are soluble in non-polar solvents but not polar solvents

Polar simple molecu;ar compounds are soluble in polar solvents but not non-polar solvents

Question 13

Can simple molecular compounds conduct electricity?

Answer 13

No

Question 14

Why can’t simple mlecular structres conduct electricity?

Answer 14

There are no free moving delocalised ions to carry a charge in simple molecular structures