Intermolecular Forces

Question 1

What is an induced dipole - dipole force (van der Waals)?

Answer 1

Attractive forces between all molecules and atoms

Question 2

How are van der Waals forces formed?

Answer 2

Electron movement in the first molecule repels electron in the second which induces a dipole in that molecule. There is then an attraction between delta plus and delta minus between the molecules

Question 3

What determines the strength of van der Waals forces?

Answer 3

Number of electrons - more electrons more forces

Number of molecules with branches - less branches have higher contact area so higher strength

Question 4

What elements form the strongest hydrogen bonds?

Answer 4

The elements with the greatest difference in electronegativity

Question 5

What elements can a hydrogen bond be formed with?

Answer 5

O, N or F

Question 6

How do you draw a hydrogen bond?

Answer 6

Add the polar charge to molecules
Add the lone pairs or electrons
Draw a dashed line for hydrogen bond and label it