Intermolecular forces

Question 1

Name given to London forces and Dipole-dipole forces

Answer 1

Van der Waal’s forces

Question 2

Dipole-dipole forces

Answer 2

• Occur between polar molecules
• Partially charged ends of molecules attract and repel each other

Also called permanent dipole

Question 3

Hydrogen bonds

Answer 3

• Very strong dipole-dipole
• Only occurs when hydrogen is bonded to nitrogen, oxygen or fluorine
• Hydrogen poles are attracted to the lone pairs

Question 4

London dispersion forces

Answer 4

• Present in any molecule
• Starts with temporary dipole with an uneven distribution of electrons, creating slightly negative and slightly oositive end
• An opposite dipole forms in a nearby molecule
• Temporary dipole spreads to all the molecules, holding them together in a solid structure.

Question 5

How to increase London forces

Answer 5

1. Larger radius has more electrons
2. More electrons
3. Less branching to allow for more surface area

Question 6

Why do the boiling points of halogens increase as you go down the group?

Answer 6

The number of electrons increases due to increasing number of energy levels, creating greater potential for a dipole as there could be a bigger difference in charge with a lot of electrons on one side