exam 1

Question 1

states of matter are dictated by

Answer 1

intermolecular forces (IMF) attraction

Question 2

stronger forces bring molecules…

Answer 2

closer together

Question 3

kinetic energy keeps molecules

Answer 3

apart and moving

Question 4

IMF solids

Answer 4

very strong
-melting points, malleability, ductility, conductivity

Question 5

IMF liquids

Answer 5

strong/middle force
-boiling points, surface tension, viscosity, vapor pressure

Question 6

IMF gas

Answer 6

essentially none

Question 7

IMFs are results from

Answer 7

the mutual attraction of unlike charges (cations and anions) or the repulsion of like charges

Question 8

IMFs are the bonds that

Answer 8

hold atoms together to form molecules

Question 9

dipole moment

Answer 9

EN difference between two atoms in a bond

Question 10

for a molecule to be polar

Answer 10

EN difference and the polar bonds cannot be canceled out

Question 11

london dispersion forces (LDF)

Answer 11

occurs between ALL molecules and is the only IMF b/w two nonpolar molecules

Question 12

LDFs are a result from

Answer 12

the motion of electrons that gives the molecule a temporary dipole moment

Question 13

molecules with greater number of e- are more polarizable which means

Answer 13

they will have stronger LDFs

Question 14

(LDF) loner, less compact molecules (w/ boiling points)

Answer 14

have higher boiling points

Question 15

(LDF) more compact molecules (w/ boiling points)

Answer 15

have lower boiling points

Question 16

Dipole-induced Dipole forces

Answer 16

occur between polar molecule and a nonpolar molecule

Question 17

a temporary dipole is created

Answer 17

on a nonpolar molecule due to the influence of neighboring on a polar molecule

Question 18

ion-dipole forces

Answer 18

occur between an ion and a polar molecule
-electrical interactions between an ion and the partial charges on a polar molecule

Question 19

dipole-dipole forces

Answer 19

occur b/w polar molecules
result of electrical interactions among dipoles on neighboring molecules

Question 20

as dipole-dipole moments increase the IMF force strength

Answer 20

increases

Question 21

as the IMF force strength increases the boiling point and melting point

Answer 21

increases

Question 22

hydrogen bonds

Answer 22

special dipole-dipole force
strongest IMF
attractive force b/w hydrogen and an EN atom (F,O,N) and an unshared electron pair on another EN atom

Question 23

when comparing substances with comparable molecular sizes

Answer 23

dipole forces are usually more significant than dispersion

Question 24

when comparing substances with very different molecular sizes

Answer 24

dispersion forces are usually more significant than dipole forces

Question 25

breaking IMFs=

Answer 25

endothermic

Question 26

creating IMFs=

Answer 26

exothermic

Question 27

violate

Answer 27

liquids that evaporate easily

Question 28

unviolate

Answer 28

liquids that don't evaporate easily

Question 29

as IMFs decrease, enthalpy of vaporization...

Answer 29

decreased/becomes slower

Question 30

dynamic equilibrium

Answer 30

-closed system -as molecules escape liquid the pressure they exert increases

Question 31

at dynamic equilibrium

Answer 31

-rates of vaporization and condensation are = -they are both occurring, but because they are opposite processes, there is no net gain or loss of vapor or liquid as equilibrium is reached

Question 32

vapor pressure

Answer 32

pressure exerted by vapor when dynamic equilibrium w/ liquid

Question 33

vapor pressure only depends on

Answer 33

IMFS and temperature

Question 34

vapor pressure does not depend on

Answer 34

volume or amount of liquid

Question 35

weaker IMFs b/w molecules (w/vapor) =

Answer 35

more molecules will begin to vapor

Question 36

weaker IMF=

Answer 36

increased/stronger vapor pressure

Question 37

increased vapor pressure (w/violateness)=

Answer 37

more violate liquids

Question 38

increased temp (with molecules)=

Answer 38

increased number of molecules able to escape

Question 39

increased temp (with vapor pressure)=

Answer 39

increased vapor pressure (so larger amount of gas particles)

Question 40

increased vapor pressure (with IMFs)=

Answer 40

decreased IMFs

Question 41

LDF decreases (w/ mm)=

Answer 41

molar mass decreases

Question 42

boiling point

Answer 42

temp of which vapor pressure = atmospheric pressure

Question 43

normal boiling point=

Answer 43

temp at which vapor is 760 torr (1 atm)

Question 44

surface tenstion

Answer 44

the energy required to break through the surface area liquid

Question 45

factors affecting surface tension (T and IMFs)

Answer 45

-liquids with strong intermolecular forces tend to have high surface tensions -raising the temp of a liquid reduces its surface tension

Question 46

raising the temperature of a liquid (with KE)=

Answer 46

increases the average kinetic energy energy of the molecules

Question 47

capillary action

Answer 47

ability of a liquid to flow against gravity up a narrow tube -involves cohesive and adhesive

Question 48

cohesive forces

Answer 48

the attraction (IMFs) between like molecules in a liquid

Question 49

adhesive forces

Answer 49

the attraction between the liquid molecules and the surface of the tube

Question 50

concave up (U-shape)

Answer 50

adhesive>cohesive

Question 51

convex (inverted shape)

Answer 51

cohesive>adhesive

Question 52

viscosity

Answer 52

liquids resistance to flow (like honey or molasses) -cohesive forces within a liquid create an internal friction which reduces the rate of flow

Question 53

stronger IMF (viscosity)=

Answer 53

the greater the viscosity

Question 54

the larger the molecular size (viscosity)=

Answer 54

the higher the viscosity

Question 55

the more branches (spherical) the molecular shape (with viscosity)=

Answer 55

the lower the viscosity

Question 56

raising temperatures (viscosity)=

Answer 56

reduces the viscosity

Question 57

miscible

Answer 57

if two liquids mixed together form homogeneous mixture -ex) water and ethanol

Question 58

immiscible

Answer 58

if two liquids mixed together to form a heterogeneous mixture -ex) oil and water

Question 59

combo of two polar compounds is

Answer 59

miscible

Question 60

combo of two nonpolar compounds is

Answer 60

miscible

Question 61

combo of a polar and nonpolar compound

Answer 61

immiscible