LEC 14: Intermolecular Forces, Liquids, and Solids

Question 1

attraction between molecules

Answer 1

intermolecular force

Question 2

much weaker than ionic or covalent bonds

Answer 2

intermolecular forces

Question 3

when a substance melts or boils, intermolecular forces are _______

Answer 3

broken

Question 4

when a substances condenses, intermolecular forces are ______

Answer 4

formed

Question 5

______ reflect intermolecular force strength

Answer 5

• boiling points
• melting point

Question 6

high boiling point indicates _______ attractive forces

Answer 6

strong

Question 7

______ melting point indicates strong attractive forces

Answer 7

high

Question 8

intermolecular forces that exist between neutral molecules

Answer 8

van der Waals forces

Question 9

van der Waals forces include:

Answer 9

• london dispersion forces
• dipole-dipole forces
• hydrogen-bonding forces

Question 10

interactions important in solutions

Answer 10

ion-dipole

Question 11

physical properties of substances are understood in terms of _______

Answer 11

kinetic-molecular theory

Question 12

highly compressible and assume the shape and volume of their container

Answer 12

gas

Question 13

_____ are far apart and do not interact much with one another

Answer 13

gas molecules

Question 14

almost incompressible, assume the shape but not the volume of the container

Answer 14

liquid

Question 15

liquid molecules are held together _____ than gas molecules but not so _____ that the molecules cannot slide past each other

Answer 15

• more closely
• rigidly

Question 16

incompressible and have a definite shape and volume

Answer 16

soild

Question 17

solid molecules are _____ together

Answer 17

packed closely

Question 18

solid molecules are _____packed that they cannot easily slide past each other

Answer 18

so rigidly

Question 19

condensed phases

Answer 19

• solid
• liquid

Question 20

solids with highly ordered structures

Answer 20

crystalline

Question 21

converting gas into a liquid or solid requires the molecules to get ____ to each other

Answer 21

closer

Question 22

converting a solid into a liquid or gas requires the molecules to move _____ apart

Answer 22

further

Question 23

forces holding solids and liquids together

Answer 23

intermolecular forces

Question 24

there are forces _____ molecules

Answer 24

between

Question 25

solid to liquid/gas conversion can be accomplished by ____ the pressure on the gas

Answer 25

heating or reducing

Question 26

gas to liquid or solid conversion can be accomplished by _____ the gas

Answer 26

cooling or compressing

Question 27

weakest of all intermolecular forces

Answer 27

london-dispersion forces

Question 28

ease with which an distribution can be deformed

Answer 28

polarizability

Question 29

the ____ the molecule, the more polarizable it is

Answer 29

larger

Question 30

london disperion forces increase as ______ increases

Answer 30

molecular weight

Question 31

london dispersion forces depend on the ____ of the molecule

Answer 31

shape

Question 32

the greater the surface area available for contact, the ____ the dispersion forces

Answer 32

greater

Question 33

london dispersion forces between spherical molecules are _____ than those between more cylindrically shaped molecules

Answer 33

smaller

Question 34

exist between neutral polar molecules

Answer 34

dipole-dipole forces

Question 35

polar molecules _____ each other

Answer 35

attract

Question 36

special type of intermolecular attraction

Answer 36

hydrogen bonding

Question 37

interaction between an ion and the partial charge on the end of a polar molecule/dipole

Answer 37

ion-dipole

Question 38

resistance of a liquid to flow

Answer 38

viscosity

Question 39

amount of energy required to increase the surface area of a liquid by a unit amount

Answer 39

surface tension

Question 40

intermolecular forces that bind molecules to one another

Answer 40

cohesive forces

Question 41

intermolecular forces that bind molecules to a surface

Answer 41

adhesive forces

Question 42

rise of liquids up very narrow tubes

Answer 42

capillary action

Question 43

changes of state

Answer 43

phase changes

Question 44

solid to gas

Answer 44

sublimation

Question 45

solid to liquid

Answer 45

melting or fusion

Question 46

liquid to gas

Answer 46

vaporization

Question 47

gas to liquid

Answer 47

desposition

Question 48

gas to liquid

Answer 48

condensation

Question 49

liquid to solid

Answer 49

freezing

Question 50

enthalpy of fusion

Answer 50

heat of fusion

Question 51

how do liquids flow

Answer 51

by sliding molecules over one another

Question 52

viscosity depends on:

Answer 52

- attractive forces between molecules - tendency of molecules to become entangled - temperature

Question 53

the stronger the intermolecular forces, the ____ the viscosity

Answer 53

higher

Question 54

viscosity ____ as molecules become entangled with one another

Answer 54

increases

Question 55

viscosity usually _____ with an increase in temperature

Answer 55

decreases

Question 56

______ (in liquid) are equally attracted to their neighbors

Answer 56

bulk molecules

Question 57

surface molecules are only attracted ____ towards the bulk molecules

Answer 57

inward

Question 58

surface molecules are packed ____ than bulk molelcules

Answer 58

more closely

Question 59

bulk molecules causes the liquid to behave as if it had a _____

Answer 59

skin

Question 60

stronger intermolecular forces causes _____ surface tension

Answer 60

higher

Question 61

water has a ____ surface tension

Answer 61

high

Question 62

hg has an _____ surface tension

Answer 62

even higher

Question 63

there are very strong ____ bonds between Hg atoms

Answer 63

metallic

Question 64

shape of the liquid surface

Answer 64

meniscus

Question 65

if _____ forces are greater than ____ forces, the meniscus is u-shaped

Answer 65

- adhesive forces - cohesive forces

Question 66

if _____ forces are greater than ______ forces, the meniscus is curved downwards

Answer 66

- cohesive forces - adhesive forces

Question 67

rise of liquids up very narrow tubes

Answer 67

capillary action

Question 68

the liquid climbs up (in capillary action) until adhesive and cohesive forces are ______

Answer 68

balanced by gravity

Question 69

endothermic phase changes:

Answer 69

- sublimation - melting or fusion - vaporization

Question 70

exothermic phase changes:

Answer 70

- freezing - deposition - condensation

Question 71

Δ H > 0 endothermic or exothermic

Answer 71

endothermic

Question 72

Δ H < 0 endothermic or exotehrmic

Answer 72

exothermic

Question 73

the heat of fusion is less than the heat of ______

Answer 73

vaporization

Question 74

it takes _____ energy to completely separate molecules than to partially separate them

Answer 74

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