Unit 1, intermolecular forces (Van der Waals)

Question 1

Intermolecular forces

Answer 1

the attractions and repulsions between molecules, which determine many of the physical properties of a substance.

Question 2

Intramolecular forces

Answer 2

Intramolecular forces are those within the molecule that keep the molecule together, for example, the bonds between the atoms.

Question 3

states of matter and IMFA

Answer 3

intermolecular forces of attraction increase from gas to liquid to solid

Question 4

types of intermolecular forces

Answer 4

strongest to weakest:
-ion-induced dipole or ion-dipole
-hydrogen bonding
-dipole-dipole
-london dispersion forces (LDF)

Question 5

Hydrogen bonding

Answer 5

-type of dipole-dipole
-polar only
-NOT a bond
-attraction btwn the hydrogen atom from an N-H, O-H, or F-H group of a molecule and a nitrogen, oxygen, or fluorine atom on another molecule
-strongest type of intermolecular force

Question 6

Dipole-dipole

Answer 6

-polar only
-forces of attraction btwn polar molecules, which have a region of partial positive charge and a region of partial negative charge
-(pos attracted to neg side of other molecule)

Question 7

London dispersion forces (LDF)

Answer 7

-non-polar
-forces of attraction btwn molecules and due to spontaneous temporary dipoles that form due to the constant motion of electrons in covalent bonds
-depends on the size (larger molecular weight=larger LDF) and shape of the molecules (more spread out=larger LDF)

Question 8

Boiling point

Answer 8

the temp at which a compound changes from liquid to gas at standard atmospheric pressure

Question 9

Weaker LDF

Answer 9

gas state of matter=low molecular weight
lower boiling point (already a gas)

Question 10

Stronger LDF

Answer 10

solid=greater molecular weight
higher boiling point