Chapter 12 and 13: Intermolecular Forces

Question 1

how are intemolecular forces to diffusion

Answer 1

IMF is inversely related to diffusion

Question 2

what is the strength of gas’s IMF

Answer 2

weak

Question 3

what is the strength of liquid’s IMF

Answer 3

moderate to strong IMF

Question 4

what is the strength of solid’s IMF

Answer 4

strong IMF

Question 5

as molecular motions increase, what happens to IMF

Answer 5

IMF decreases as molecular motions increase

Question 6

how is kinetic energy related to IMF

Answer 6

IMF and KE are inversely related; when KE is high, IMF is low

Question 7

what are intermolecular forces?

Answer 7

IMF is how atoms, molecules, and ions are attracted to or repelled from one another

Question 8

intermolecular forces operate where in the molecule?

Answer 8

between molecules

Question 9

IMF are based on what?

Answer 9

electrical interactions (unlike charges attract, like charges repel)

Question 10

what does IMF do for molecules?

Answer 10

it hols them toghter in liquid and solids

Question 11

strength of IMF depends on the BLANK of the molecules

Answer 11

structure

Question 12

what are two key factors in the strength of IMF regarding structure of the molecule

Answer 12

the polarity and size of molecule

Question 13

what is the boiling point of a liquid a measure of?

Answer 13

The strength of the IMF

Question 14

the stronger the attractive forces in a liquid, the BLANK the temperature needed for separating the molecules form liquid state to a vapor

Answer 14

higher the temperature

Question 15

what is indicated when size is similar but boiling point is different

Answer 15

the polarity of the molecules is different

Question 16

what are the 4 types of IMF?

Answer 16

dipole-dipole forces, ion-dipole forces, hydrogen bonds, and dispersion forces

Question 17

what is dipole-dipole force?

Answer 17

ineraction between 2 polar molecules

Question 18

what is ion-diple force?

Answer 18

interaction between ion and a polar molecule

Question 19

what is dispersion force?

Answer 19

interaction that occurs between ALL molecules

Question 20

stength of dispersion force depends on what?

Answer 20

molecular size

Question 21

what is hydrogen bond?

Answer 21

interaction between N-H, O-H, or F-H bond and a lone pair on an electronegative N, O, F atom on another molecule

Question 22

polar molecules have what kind of charges?

Answer 22

opposite charges

Question 23

the more polar a molecule the BLANK the dipole-dipole force

Answer 23

stronger

Question 24

all hydrocarbons are nonpolar or polar?

Answer 24

nonpolar

Question 25

what do disperions forces do to the electron cloud around a molecule or an atom?

Answer 25

dipsersion forces distort the cloud—think of a sphere being pulled into an egg shape

Question 26

why are larger molecules more polarizable?

Answer 26

larger molecules have greater number of electrons, thus their electrons are farther from the nuclei

Question 27

disperson forces generally increase with size, except when what bonds are involved?

Answer 27

hydrogen bonds

Question 28

strength of ion-dipole forces depend on what 3 things?

Answer 28

charge of the ion, size of the ion, and polarity the molecule

Question 29

in ion-dipole forces, what is the relationship between charge of ion and strength of force?

Answer 29

higher the charge, stronger the force

Question 30

in ion-dipole forces, what is the relationship between size of ion and strength of force?

Answer 30

the smaller the ion, the stronger the ion-dipole force

Question 31

in ion-dipole forces, what is the relationship between polarity of molecule and strength of force?

Answer 31

the more pole, the stronger the force

Question 32

what is vapor pressure of a liquid

Answer 32

the pressure exerted by the apor particles in equilibrium with the liquid at constant temperature

Question 33

in a closed container, rate of evaporation =

Answer 33

rate of condensation

Question 34

how is vapor pressure of a liquid related to stregth of IMF

Answer 34

vapor pressure is inversely related to strength of IMF; stronger IMF equals lower vapor pressure

Question 35

vapor pressure increases and what increases?

Answer 35

temperature

Question 36

what is the strongest intermolecular force and why?

Answer 36

ion-ion force, they have the highest formal charge

Question 37

what is the second strongest intermolecular force and why?

Answer 37

ion-dipole force, the charge of any ion is much greater than the charge of a dipole

Question 38

why are hydrogen bonds stronger than most dipole dipole forces?

Answer 38

hydrogen bonds contain O, N, and F, which are 3 of the most electronegative elements, therefore the most polarized

Question 39

describe partial polarity in London dispersion force

Answer 39

one side of an atom is slightly negative and one side is slightly positive... SLIGHTLY

Question 40

in a liquid, the amount of heat energy stored equals what?

Answer 40

the precise amount of energy needed for the particles to be liberated to a gas

Question 41

relationship between boiling point and attraction force

Answer 41

the stronger the attraction force of a substance, the higher the boiling point (or energy needed) to melt/boil/break the bonds