11. Liquids, Solids, Intermolecular Forces

Question 1

ThermAl energy high relative to intermolecular forces then matter tends to be ____

Answer 1

Gaseous

Question 2

Thermal energy low relative to intermolecular forces then matter tends to be ____

Answer 2

Liquid or solid

Question 3

Solid and liquid densities are ____ than gas

Answer 3

Greater

Question 4

Thermal energy ___ attractions between a molecules in a liquid

Answer 4

Overcomes

Question 5

Liquids

Answer 5

Not easily compressed
Molecules are in close contact
High density
Moderate IMF

Question 6

Gas

Answer 6

Easily compressed
Become gas at higher temperatures or reduced pressure
Molecules stay in tact but break IMFs

Question 7

Solid

Answer 7

Not compressible
Solid at cooler temperatures
May be crystalline(well ordered 3D array) or amorphous(no order)

Question 8

At room temperature moderate to strong IMFs tend to be____ and have high melting and boiling points

Answer 8

Liquids or sounds

Question 9

At room temperature weak IMFs tend to be____ and have low melting and boiling points

Answer 9

Gaseous

Question 10

Binding forces are ___ IMFs because _____

Answer 10

Stronger than; they have large charges(protons and electrons) interacting closely

Question 11

IMFs are ____ binding forces because ____

Answer 11

Weaker than; because smaller charges at higher distances

Question 12

Dispersion forces

Answer 12

. Exist in all molecules
. Result in electrons being unevenly distributed causing an instantaneous dipole
. The magnitude of the forces depends on size of molecule( bigger molecule means electrons are more shielded from nucleous)
. As dispersion force increase (bigger molar) boiling point increases
Shape matters if there is more area to interact

Question 13

Dipole-dipole forces

Answer 13

.exist in polar molecules
.polar ends create slightly charged ends attracting other polar molecules
. Stronger than dispersion forces
. Has to have net dipole

Question 14

Hydrogen bonding

Answer 14

. Occurs when a polar molecule contains an H bonded to F O N
. Hydrogen carries large partial positive charge when bonded to these molecules
. Also small distances create stronger bonds

Question 15

Ion-dipole forces

Answer 15

Positive ions interacting with polar ends of molecules

Strongest of all IMFs

Question 16

Surface tension

Answer 16

Energy required to increase surface area

Question 17

Oscillating

Answer 17

Move back and forth at regular speed

Question 18

Vaporization

Answer 18

Thermal energy overcoming intermolecular forces. Endothermic(requires heat). Liquid to gas

Question 19

Higher temperature results in —- average energy for the molecule

Answer 19

Higher

Question 20

Condensation

Answer 20

Molecules plunge back into substance; lower end of energy curve. Exothermic releases heat( steam on hand) gas to liquid

Question 21

Volatile

Answer 21

Easily evaporate( weak IMFs) low boiling

Question 22

Heat of vaporization

Answer 22

Amount of heat requires to vaporize one mole of liquid to a gas(always positive because it is absorbing) if substance is hotter the Hvap can be lower because less heat is required. Units: kj/mole

Question 23

Dynamic equilibrium

Answer 23

Rate of condensation and vaporization becomes constant. In sealed container at constant temperature

Question 24

Vapor pressure

Answer 24

Pressure of gas in dynamic equilibrium with liquid. Depends on IMFs and temperature

Question 25

Le chatelier princple

Answer 25

When a system in dynamic equilibrium is disturbed it will minimize or maximize to return to equilibrium

Question 26

Temperature and vapor pressure

Answer 26

As temperature increases vapor pressure increases, it allows more molecules to vaporize

Question 27

Boiling point

Answer 27

Temperature at which vapor pressure equals external pressure(allows molecules to break free from interior not just surface) no external pressure pushing down