Unit 5 - IMFAs

Question 1

Intermolecular Forces

Answer 1

Forces that exist between covalent molecules

Question 2

Intramolecular forces

Answer 2

Forces that hold atoms together within a molecule

Question 3

London Dispersion Forces

Answer 3

Caused by a temporary dipole due to an unequal distribution of electrons (weakest of the IMFAs and the predominant force in nonpolar molecules)

Question 4

Are smaller or larger molecules stronger?

Answer 4

Larger molecules will have stronger lDFS than smaller molecules because more electrons result in larger temporary dipoles, resulting in a stronger IMFA

Question 5

Dipole-Dipole

Answer 5

Caused by a permanent dipole, which exists as a result of the electronegativity differences between the atoms in a bond (predominant force in polar molecules)

Question 6

H-Bonding

Answer 6

Occurs in molecules that contain H-O, H-N, or H-F bonds and is caused by the extreme difference in EN between the atoms of the bond (strongest IMFA)

Question 7

Nonpolar Covalent Bond

Answer 7

0.0-0.4 EN difference

Question 8

Polar Covalent Bond

Answer 8

0.5-1.8 EN difference

Question 9

Ionic Bond

Answer 9

1.8+ EN difference

Question 10

Polar molecules must have…

Answer 10

1 polar bond its molecular shape must be asymmetrical (different atoms around central atom and lone pairs around central atom)

Question 11

Relationship between IMFAs and Boiling Point

Answer 11

The stronger the IMFA bond