6.3 - Intermolecular Forces

Question 1

What are the 2 types of intermolecular forces?

Answer 1

• hydrogen bonding
• dipole forces

Question 2

What is the strongest type of intermolecular force?

Answer 2

Hydrogen bonding

Question 3

What are the 2 interactions that can be referred to as dipole forces?

Answer 3

• permanent dipole - induced dipole interaction
• permanent dipole - permanent dipole interaction

Question 4

Describe permanent dipole-induced dipole interactions?

Answer 4

When a molecule with a permanent dipole is close to other non polar molecules it causes The non polar molecule to become slightly polar leading to attraction

Question 5

Describe permanent dipole - permanent dipole interactions?

Answer 5

Some molecules with polar bonds have permanent dipoles —> forces of attraction between those dipoles and those of neighbouring molecules

Question 6

Describe London forces

Answer 6

• caused by random movements of electrons
• leads to instantaneous dipoles
• instantaneous dipole induces a dipole in nearby molecules
• induced dipoles attract one another

Question 7

Does b.p increase or decrease down the noble gas group?

Answer 7

Boiling point increases as the number of electrons increases and hence the strength of London forces also increases

Question 8

What is a dipole?

Answer 8

Difference in charge between the two atoms caused by a shift in electron density in the bond