Intermolecular Forces

Question 1

IMF

Answer 1

• forces between molecules weak
• london forces
• permanent dipole - permanent dipole
• hydrogen bonding

Question 2

london forces

Answer 2

• cause all atoms and molecules to be attracted to each other
• electrons in charge clouds always moving really quickly

Question 3

Dipole

Answer 3

• any particular moment electrons in atoms are more likely to be more to one side then the other
• this moment atom would have a temporary dipole
• dipole can induce another temporary dipole on the opposite direction on a neighbouring atom
• 2 dipoles are attracted to each other
• second dipole cna induce yet another dipole in a third atom so its like a domino effect
• electrons are constantly moving so dipoles being created and destroyed all the time
• even tho they keep changing overall effect is for atoms to be attracted to each other

Question 4

london forces lattice

Answer 4

• molecules held together in a molecular lattice arrangement by weak london forces
• simple molecular structure

Question 5

stronger london forces

Answer 5

• high m+bp
• larger molecules have larger electron clouds so stronger london forces
• more molecular surface contact and more electrons to interact
• longer so harder to seperate
• more energy needed to overcome london forces
• branched chain alkanes can’t pack closely together and their molecular surfacer contact is small compared to straight chain alkanes of similar molecular mass

Question 6

polar molecules

Answer 6

• have permanent dipole - permanent dipole bonds
• delta + and delta - charges on polar molecules cause weak electrostatic forces of attraction between molecules
• pdpd bonds as well as lf
• generally hmp+BP