Intermolecular forces

Question 1

What are intermolecular forces?

Answer 1

Attractions between different molecules. They are much weaker than bonds.

Question 2

What are London dispersion forces?

Answer 2

They are weak attractions that exist between all molecules. One end becomes temporarily charged due to chance and introduces a charge in a nearby molecule.

Question 3

Do smaller or larger molecules have stronger van der waals molecules?

Answer 3

Larger.

Question 4

What are dipole-dipole forces?

Answer 4

They are stronger than London forces and exist when there is a pure covalent bond. Attractions between partially positive and partially negative ends of the molecule.

Question 5

What are hydrogen bonds?

Answer 5

Strongest type of intermolecular force. Exists when there is a O-H, N-H or H-F bond.

Question 6

What are 2 essential requirements for formation of hydrogen bond?

Answer 6

• A hydrogen atom must be directly bonded to a highly electronegative atom (e.g. N, O, F).
• An unbonded pair of electrons (lone pair electrons) is presented on the electronegative atom.

Question 7

What are Van der Waals forces?

Answer 7

Dipole-dipole and London dispersion forces.