Chemistry Test 4 Chapter 12

Front 1

Interactions Between Molecules
Many of the phenomena we observe are related to interactions between molecules that do not involve a _____________.

Back 1

chemical reaction.

Front 2

Structure determines ___________.

Back 2

properties

Front 3

Low densities compared to solids and liquids.

Back 3

Gases

Front 4

Fluid.
The material exhibits a smooth, continuous flow as it moves.

Back 4

Gases

Front 5

Take the shape of their container(s).

Back 5

Gases

Front 6

Expand to fill their container(s).

Back 6

Gases

Front 7

Can be compressed into a smaller volume.

Back 7

Gases

Front 8

In the _______, the particles have complete freedom from each other.

Back 8

gas state

Front 9

(gas state) The ______ are constantly flying around, bumping into each other and their container(s).

Back 9

particles

Front 10

In the _______, there is a lot of empty space between the particles. (On average.)

Back 10

gas state

Front 11

Because there is a lot of empty space, the particles can be squeezed closer together. Therefore, gases are _________.

Back 11

compressible

Front 12

(gas state) Because the particles are not held in close contact and are moving freely, gases expand to fill and take the shape of their ________, and will flow.

Back 12

container(s)

Front 13

High densities compared to gases.

Back 13

Liquids

Front 14

Fluid.
-The material exhibits a smooth, continuous flow as it moves. (not gases)

Back 14

Liquids

Front 15

Take the shape of the bottom of their container(s).

Back 15

Liquids

Front 16

Keep their volume, do not expand to fill their container(s).

Back 16

Liquids

Front 17

Cannot be compressed into a smaller volume.

Back 17

Liquids

Front 18

The particles in a _____ are closely packed, but they have some ability to move around.

Back 18

liquid

Front 19

The close packing results in liquids being
__________.

Back 19

incompressible.

Front 20

The ability of the particles to move allows _______ to take the shape of their container and to flow. However, they don’t have enough freedom to escape and expand to fill the ________.

Back 20

liquids, container(s)

Front 21

High densities compared to gases.

Back 21

Solids

Front 22

Nonfluid.
They move as an entire “block” rather than a smooth, continuous flow.

Back 22

Solids

Front 23

Keep their own shape, do not take the shape of their container(s).

Back 23

Solids

Front 24

Keep their own volume, do not expand to fill their container(s).

Back 24

Solids

Front 25

Cannot be compressed into a smaller volume.

Back 25

Solids

Front 26

The particles in a ______ are packed close together and are fixed in position.
--Though they are _______.

Back 26

solid, vibrating

Front 27

The close packing of the particles results in solids being __________.

Back 27

incompressible

Front 28

The inability of the particles to move around results in _____ retaining their shape and volume when placed in a new container, and prevents the particles from flowing.

Back 28

solids

Front 29

Some ______ have their particles arranged in an orderly geometric pattern. We call these ___________.
---Salt and diamonds.

Back 29

solids, crystalline solids

Front 30

Other _______ have particles that do not show a regular geometric pattern over a long range. We call these ____________.
---Plastic and glass.

Back 30

solids, amorphous solids.

Front 31

The ______ a material exists in depends on the attraction between _______ and their ability to overcome the attraction.

Back 31

state, molecules

Front 32

The attractive forces between ions or molecules depends on their ______.
----The attractions are electrostatic.
---- They depend on shape, polarity, etc.

Back 32

structure

Front 33

The ability of the molecules to overcome the attraction depends on the amount of ________ they possess.

Back 33

kinetic energy

Front 34

Phase Changes
Adding _____ _____increases the amount of kinetic energy of the molecules in the solid.

Back 34

heat energy (Solid to Liquid)

Front 35

Phase Changes
Adding heat energy increases the amount of kinetic energy of the molecules in the solid.

Eventually, they acquire enough energy to partially overcome the _______ _______ holding them in place.

Back 35

attractive forces (Solid to Liquid)

Front 36

Phase Changes
Adding heat energy increases the amount of kinetic energy of the molecules in the solid.
Eventually, they acquire enough energy to partially overcome the attractive forces holding them in place.
This allows the ______ enough extra freedom to move around a little and rotate.

Back 36

molecules (Solid to Liquid)

Front 37

Phase Changes
Adding heat energy increases the amount of _____ _______ of the molecules in the liquid.

Back 37

kinetic energy (Liquid to Gas)

Front 38

Phase Changes
Adding heat energy increases the amount of kinetic energy of the molecules in the liquid.
Eventually, they acquire enough _____ to completely overcome the attractive forces holding them together.

Back 38

energy (Liquid to Gas)

Front 39

Phase Changes
Adding heat energy increases the amount of kinetic energy of the molecules in the liquid.
Eventually, they acquire enough energy to completely overcome the attractive forces holding them together.
This allows the molecules _________ ________ to move around and rotate.

Back 39

complete freedom (Liquid to Gas)

Front 40

Liquids tend to minimize their surface—a phenomenon we call ______ _______.

Back 40

surface tension

Front 41

This tendency causes liquids to have a surface that resists ________. (surface tension)

Back 41

penetration

Front 42

The _______ the attractive force between the molecules, the larger the surface tension.

Back 42

stronger

Front 43

The stronger the attractive force between the molecules, the larger the _______ ________.

Back 43

surface tension

Front 44

Some liquids ____ more easily than others.

Back 44

flow

Front 45

The resistance to flow is called ________.

Back 45

viscosity

Front 46

The stronger the attractive forces between the molecules, the more _______ the liquid.

Back 46

viscous

Front 47

Also, the less ______ the molecule’s shape, the larger the liquid’s ________.
---Some liquids are more viscous because their molecules are long and get tangled in each other, causing them to resist flowing.

Back 47

round, viscosity

Front 48

The process of liquid molecules breaking free from the surface is called _______.

Back 48

evaporation

Front 49

The process of liquid molecules breaking free from the surface is called evaporation.
---Also known as ______.

Back 49

vaporization

Front 50

Evaporation is a _____ change in which a substance is converted from its liquid form to its gaseous form.
---The gaseous form is called a ________.

Back 50

physical, vapor

Front 51

Over time, liquids ________—the molecules of the liquid mix with and dissolve in the air.

Back 51

evaporate

Front 52

Evaporation happens ____ ____ ______.

Back 52

at the surface.

Front 53

Molecules on the surface experience a smaller net ________ ______ than molecules in the interior.

Back 53

attractive force

Front 54

Molecules on the ______ experience a smaller net attractive force than molecules in the interior

Back 54

surface

Front 55

Molecules on the surface experience a smaller net attractive force than molecules in the _______.

Back 55

interior

Front 56

All the surface molecules do not escape at once, only the ones with sufficient ________ ______ to overcome the attractions will escape.

Back 56

kinetic energy

Front 57

All the surface molecules do not escape at once, only the ones with sufficient kinetic energy to overcome the _______ will escape.

Back 57

attractions

Front 58

The _______ kinetic energy is directly proportional to the Kelvin temperature.

Back 58

average

Front 59

Those molecules on the surface that have enough ______ _____ will escape.
---Raising the ________ increases the number of molecules with sufficient energy to escape

Back 59

kinetic energy, temperature

Front 60

Since higher energy molecules from liquid leave, the total kinetic energy of the liquid ________, and the liquid .

Back 60

decreases, cools

Front 61

Since the higher energy molecules from the liquid are leaving, the total kinetic energy of the liquid decreases, and the liquid cools.
The remaining molecules ______ their energies, generating more ______ ________ molecules.

Back 61

redistribute, high energy

Front 62

Since the higher energy molecules from the liquid are leaving, the total kinetic energy of the liquid decreases, and the liquid cools.
The remaining molecules redistribute their energies, generating more high energy molecules.
The result is that the liquid continues to ________ .

Back 62

evaporate

Front 63

Factors Effecting Rate of Evaporation
Liquids that evaporate quickly are called ______ liquids, while those that do not are called ________.

Back 63

volatile, non-volatile

Front 64

Factors Effecting Rate of Evaporation
Increasing the _______ _______ increases the rate of evaporation.
-More surface molecules

Back 64

surface area

Front 65

Factors Effecting Rate of Evaporation
Increasing the ________ increases the rate of evaporation.
---Raises the average kinetic energy, resulting in more molecules that can escape.

Back 65

temperature

Front 66

Factors Effecting Rate of Evaporation
_________ attractive forces between the molecules = faster rate of evaporation.

Back 66

Weaker

Front 67

Condensation
When a liquid evaporates in a closed container, the vapor molecules are ________ .

Back 67

trapped

Front 68

The vapor molecules may eventually bump into and stick to the surface of the container or get recaptured by the liquid. This process is called __________ .
A ________ change in which a gaseous form is converted to a liquid form.

Back 68

condensation, physical

Front 69

Evaporation and condensation are ________ processes.

Back 69

opposite

Front 70

Evaporation and condensation are opposite processes.
Eventually, the rate of evaporation and rate of condensation in the container will be ____ ______.

Back 70

the same

Front 71

Opposite processes that occur at the same rate in the same system are said to be in _______ ________.
----Imagine an evenly balanced, moving “see-saw”.

Back 71

dynamic equilibrium

Front 72

Once dynamic equilibrium is reached, from that time forward, the amount of _____ in the container will remain the same.
---As long as you don’t change the conditions.

Back 72

vapor

Front 73

Once equilibrium is reached, from that time forward, the amount of vapor in the container will remain the same. (As long as you don’t change the conditions.)
The partial pressure exerted by the vapor is called the _____ ______.

Back 73

vapor pressure

Front 74

The vapor pressure of a liquid depends on the temperature and strength of ______ attractions.

Back 74

intermolecular

Front 75

In an open container, as you heat a liquid the average kinetic energy of the molecules ______, giving more molecules enough energy to escape the surface. (So the rate of evaporation increases.)

Back 75

increases

Front 76

In an open container, as you heat a liquid the average kinetic energy of the molecules increases, giving more molecules enough energy to escape the surface. (So the rate of evaporation increases.)
Eventually, the temperature is high enough for molecules in the interior of the liquid to escape. A phenomenon we call _________.

Back 76

boiling

Front 77

The temperature at which the vapor pressure of the liquid is the same as the atmospheric pressure is called the _____ _____. (The temperature at which the _____ boils)

Back 77

boiling point, liquid

Front 78

The boiling point depends on what the ________ pressure is. (The temperature of boiling water on the top of a mountain will be cooler than boiling water at sea level.)

Back 78

atmospheric

Front 79

The temperature of boiling water on the top of a mountain will be cooler than ______ water at sea level.

Back 79

cooler

Front 80

As you heat a liquid, its temperature increases until it reaches its _______ ______.

Back 80

boiling point.

Front 81

As you heat a liquid, its temperature increases until it reaches its boiling point.
Once the liquid starts to boil, the temperature remains the same until it all turns to a ____.

Back 81

gas

Front 82

As you heat a liquid, its temperature increases until it reaches its boiling point.
Once the liquid starts to boil, the temperature remains the same until it all turns to a gas.
All the ______ from the heat source is being used to overcome all of the attractive forces in the liquid.

Back 82

energy

Front 83

As it ______ its high energy molecules through evaporation, a liquid cools.

Back 83

loses

Front 84

As it loses its high energy molecules through evaporation, a liquid cools.
The liquid then _____ ____ from its surroundings to maintain its temperature.

Back 84

absorbs heat

Front 85

Processes in which heat flows into a system from the surroundings are said to be _______.

Back 85

endothermic

Front 86

As heat flows out of the surroundings, it causes the surroundings to ______.
As alcohol evaporates off your skin, it causes your skin to _____.

Back 86

cool, cool

Front 87

As it gains the high energy molecules through condensation, a liquid ______.

Back 87

warms

Front 88

As it gains the high energy molecules through condensation, a liquid warms.
The liquid then releases heat to its surroundings to maintain its _________.

Back 88

temperature

Front 89

Processes in which heat flows out of a system into the surroundings are said to be ________.

Back 89

exothermic

Front 90

Processes in which heat flows out of a system into the surroundings are said to be exothermic.
As heat flows into the surroundings, it causes the surroundings to _______.

Back 90

warm

Front 91

The amount of heat needed to vaporize one mole of a liquid is called the _____ of _______.

Back 91

heat, vaporization

Front 92

_______ required to vaporize one mole of water at 100 °C.

Back 92

40.7 kJ

Front 93

40.7 kJ required to vaporize ____ _____ of water at 100 °C.

Back 93

one mole

Front 94

40.7 kJ required to vaporize one mole of water at _____.

Back 94

100 °C.

Front 95

D(<-- triangle)Hvap depends on the _____ _______.

Back 95

initial temperature.

Front 96

Since condensation is the opposite process to evaporation, the same amount of energy is transferred but in the _____ _______.

Back 96

opposite direcion

Front 97

kJ / mol
cal / mol etc

Back 97

Heat of vaporization units:

Front 98

As you heat a solid, its temperature increases until it reaches its _____ _____.

Back 98

melting point

Front 99

As you heat a solid, its temperature increases until it reaches its melting point.
Once the solid starts to melt, the temperature remains the same until it all turns to a _____.

Back 99

liquid

Front 100

As you heat a solid, its temperature increases until it reaches its melting point. Once the solid starts to melt, the temperature remains the same until it all turns to a liquid. All the energy from the heat source is being used to overcome some of the ______ ______ in the solid that hold them in place.

Back 100

attractive forces

Front 101

When a solid melts, it absorbs heat from its surroundings, it is _________ .

Back 101

endothermic

Front 102

When a liquid freezes, it releases heat into its surroundings, it is ________.

Back 102

exothermic

Front 103

As heat flows out of the surroundings, it causes the surroundings to ____.
As heat flows into the surroundings, it causes the surroundings to ______.

Back 103

cool, warm

Front 104

The amount of heat needed to melt one mole of a solid is called the _____ of _____.

Back 104

fusion

Front 105

Since freezing (crystallization) is the opposite process of melting, the amount of energy transferred is the ____, but in the opposite direction.

Back 105

same

Front 106

_______ is a physical change in which the solid form changes directly to the gaseous form.
(Without going through the liquid form.)

Back 106

Sublimation

Front 107

Like melting, sublimation is _____.

Back 107

endothermic

Front 108

The stronger the ______ forces of attraction, the more energy it takes to separate the molecules.

Back 108

intermolecular

Front 109

Substances with strong ______ forces have higher boiling points, melting points, and heat of vaporization; they also have lower vapor pressures.

Back 109

intermolecular

Front 110

________forces are a result of attractive forces between opposite charges e.g.:

+ ion to – ion.

Back 110

Intermolecular

Front 111

Why Are Molecules Attracted to Each Other?

Back 111

Intermolecular forces are a result of attractive forces between opposite charges e.g.:

Front 112

Also known as London forces or instantaneous dipoles.

Back 112

Dispersion Forces

Front 113

Caused by distortions in the electron cloud of one molecule inducing distortion in the electron cloud on another molecule.
--Distortions in the electron cloud lead to a temporary dipole.

Back 113

Dispersion Forces

Front 114

The instantaneous dipole induces dipoles in neighboring atoms/molecules -- _____ ______.

Back 114

induced dipoles

Front 115

The temporary dipoles lead to attractions between atoms/molecules— _______ ______ .

Back 115

dispersion forces

Front 116

___ ______ have attractions caused by dispersion forces.

Back 116

All molecules

Front 117

Strength of the Dispersion Force depends on how easily the electrons can move, or be _______.

Back 117

polarized

Front 118

The more electrons and the farther they are from the _____, the larger the dipole that can be induced.

Back 118

nuclei

Front 119

Strength of the dispersion force gets larger with____ ____ (larger molar mass).

Back 119

larger molecules

Front 120

Strength of the dispersion force gets larger with larger molecules (larger _____ _____ ).

Back 120

molar mass

Front 121

Strength of the ____ _____ gets larger with larger molecules (larger molar mass).

Back 121

dispersion force

Front 122

The stronger the intermolecular force, the higher the ____ _____.
--In general, ___ ___ increases with molar mass

Back 122

boiling point, boiling point

Front 123

Polar molecules have _____ _____.

Back 123

permanent dipoles

Front 124

All molecules are attracted by _____ forces.

Back 124

dispersion

Front 125

Dispersion forces increase with ____ ____.

Back 125

molar mass

Front 126

Polar molecules have ____ forces and _____-dipole forces.

Back 126

dispersion, dipole

Front 127

The strength of attraction is stronger between ____ molecules than between non-polar molecules of the same size.
--Boiling points of polar molecules will be higher than those of non-polar molecules of approximately the same size.

Back 127

polar

Front 128

“Like-dissolves-____”

Back 128

like

Front 129

Polar molecules tend to dissolve in _____ solvents

Back 129

polar

Front 130

Non-polar molecules tend to dissolve in non-polar _____.

Back 130

solvents

Front 131

When liquid pentane, a non-polar substance, is mixed with water, a polar substance, the two liquids _______ because they are more attracted to their own kind of molecule than to the other.

Back 131

separate

Front 132

Molecules that contain H ___ ____ to N, O or F have particularly strong intermolecular attractions.
(Unusually high melting and boiling points.)

Back 132

directly bonded

Front 133

Molecules that contain H directly bonded to N, O or F have particularly strong intermolecular attractions.
Unusually high melting and boiling points. This kind of attraction is called a ____ ____. Actually an intermolecular force NOT a chemical bond.

Back 133

hydrogen bond

Front 134

When a very _______ atom is bonded to hydrogen, it strongly pulls the bonding electrons toward it.

Back 134

electronegative

Front 135

When a very electronegative atom is bonded to hydrogen, it strongly pulls the bonding electrons toward it. Since hydrogen has no other electrons, when it loses the electrons, the nucleus becomes _______. (Exposing the proton.)

Back 135

deshielded

Front 136

When a very electronegative atom is bonded to hydrogen, it strongly pulls the bonding electrons toward it. Since hydrogen has no other electrons, when it loses the electrons, the nucleus becomes deshielded. (Exposing the proton.) The exposed proton acts as a very strong center of positive charge, attracting all the ____ _____ from neighboring molecules.

Back 136

electron clouds

Front 137

Water contains __-bonds

Back 137

H

Front 138

Hydrogen bonds are not ______ bonds.

Back 138

chemical

Front 139

Hydrogen bonds are _____ ______between molecules.

Back 139

attractive forces

Front 140

Hydrogen bonds are attractive forces _____ molecules.

Back 140

between

Front 141

Hydrogen bonds are/are not chemical bonds?

Back 141

are not

Front 142

Chemical bonds are attractive forces that ____ molecules.

Back 142

make

Front 143

____ ____ are solids whose composite units are molecules.

Back 143

Molecular solids

Front 144

Molecular solids are solids whose composite units are molecules.
Solid held together by _____ attractive forces.
Dispersion, dipole-dipole, or H-bonding.

Back 144

intermolecular

Front 145

____ _____ are solids whose composite units are formula units.

Back 145

Ionic solids

Front 146

Ionic solids are solids whose composite units are formula units.
Solid held together by electrostatic attractive forces between _____ and ______.

Back 146

cations, anions

Front 147

Cations and anions arranged in a geometric pattern called a _____ ____ to maximize attractions.

Back 147

crystal lattice

Front 148

_____ _____ are solids whose composite units are individual atoms

Back 148

Atomic solids

Front 149

Atomic solids are solids whose composite units are individual atoms.
Solids held together by either ______ bonds, dispersion forces, or metallic bonds.

Back 149

covalent

Front 150

In the simplest model of a metal, each atom
donates one or more ____ to an "electron sea." The metal then consists of the metal cations in a negatively-charged electron sea.

Back 150

electrons

Front 151

Water is found in all three ____ on Earth.

Back 151

states

Front 152

As a liquid, it is the most common _____ found in nature.

Back 152

solvent

Front 153

Without ____, life as we know it could not exist.
The search for extraterrestrial life starts with the search for ____.

Back 153

water, water

Front 154

Water is ____ at room temperature.
Most molecular substances that have a molar mass similar to water’s (18.02 g/mol) are ____.

Back 154

liquid, gaseous

Front 155

Water has an unusually high ____ ____ for Molar Mass.
Due to __-bonding.

Back 155

boiling point, H

Front 156

Water ____ as it freezes. Most substances ____ as they freeze.

Back 156

expands, contract

Front 157

Water Expands as it freezes.
Most substances contract as they freeze.
Causes ice to be ___ dense than liquid water.
Allows life in lakes and oceans to survive winter

Back 157

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