Ch 12 Section 2

Question 1

molecules or ions of the solute are

Answer 1

attracted by the solvent

Question 2

because the dissolution process occurs at the surface of the solute, it can be speeded up if the surface area of the solute is

Answer 2

increased

Question 3

in general, the more finely divided a substance is, the greater the surface area per unit mass and the more

Answer 3

quickly it dissolves

Question 4

very close to the surface of a solute, the concentration of dissolved solute is

Answer 4

high

Question 5

stirring or shaking helps to disperse the solute particles and bring fresh solvent into

Answer 5

contract with the solute surface

Question 6

the effect of stirring results in increased contact between the

Answer 6

solvent and the solute surface

Question 7

as the temperature of the solvent increases, solvent molecules move faster, and their

Answer 7

average kinetic energy increases

Question 8

at higher temperatures, collisions between the solvent molecules and the solute are more frequent and are of higher energy than at

Answer 8

lower temperatures

Question 9

this helps to separate solute molecules from one another and to disperse them among the

Answer 9

solvent molecules

Question 10

for every combination of solvent with a solid solute at a given temperature, there is a limit to the amount of solute that can be

Answer 10

dissolved

Question 11

the point at which this limit is reached for any solute solvent combination is difficult to predict precisely and dpends on the nature of the

Answer 11

solute, nature of the solvent, as well as the temperature

Question 12

as more solid dissolves and the concentration of dissolved molecules increases, collisions become more

Answer 12

frequent

Question 13

eventually, molecules are returning to crystal at the same rate at which they are going into solution, and a dynamic equilibriuim is established between

Answer 13

dissolution and crysstallization

Question 14

solution equilibrium is the physical state in which the opposing processes of dissolution and crystallization of a solute occur at

Answer 14

equal rates

Question 15

a solution that contains the maximum amount of dissolved solute is described as a

Answer 15

saturated solution

Question 16

a solution that contains less solute than a saturated solution under the existing conditions is an

Answer 16

unsaturated solution

Question 17

when a saturated solution of a solute whose solubility increases with temperature is cooled, the excess solute usually comes out of solution, leaving the solution satureated at the

Answer 17

lower tempearture

Question 18

sometimes, if the solution is left to cool undistrubted, the excess solute does not separate and a

Answer 18

supersaturated solution is produced

Question 19

a supersaturated solution is a solution that contains more dissolved solute than a saturated solution contains under the

Answer 19

same conditions

Question 20

a supersaturated solution may remain unchanged for a long time it if is not disturbed, but once crystals begin to form, the process continues until equilibrium is

Answer 20

reestablished at the lower temperature

Question 21

the solubility of a substance is the amount of that substance required to form a saturated solution with a specific amount of … at a specified …

Answer 21

solvent; temperature

Question 22

the temperature must be specified because solubility varies with

Answer 22

temperature

Question 23

for gases, pressure must also be

Answer 23

specified

Question 24

the rate at which a solid dissolves is unrelated to its solubility at that

Answer 24

temperature

Question 25

the maximum amount of a given solute that dissolves and reaches equilibrium is always the same under the

Answer 25

same conditions

Question 26

"like dissolves like" is a useful rule for predicting whether one substance will

Answer 26

dissolve in another

Question 27

what makes substances similar depends on the type of bonding, the polarity or nonpolarity of molecules, and the intermolecular forces between the

Answer 27

solute and solvent

Question 28

the polarity of water molecules plays an important role in the formation of solutions of

Answer 28

ionic compounds in water

Question 29

the slightly charged parts of water molecules attract the ions in the ionic compound and surround them to keep them separated from the other

Answer 29

ions in the solution

Question 30

this solution process with water as the solvent is referred to as

Answer 30

hydration

Question 31

as ydrated ions diffuse into the solution, other ions are exposed and are drawn away from the

Answer 31

crystal surface by the solvent

Question 32

the entire crystal gradually dissolves and hydrated ions become unifromly

Answer 32

distributed in the solution

Question 33

when crystallized from aqueous solutions, some ionic substances form crystals that incorporate water

Answer 33

molecules

Question 34

these crystalline compounds, hydrates, retain specific ratios of water molecules and are represented by formulas such as

Answer 34

CuSO4 . 5H2o

Question 35

heating the crystals of hydrate can drive off the wter of hydration and leave the

Answer 35

anhydrous salt

Question 36

when a crystalline hydrate dissolves in water, the water of hydration returns to

Answer 36

the solvent

Question 37

the behavior of a solution made from a hydrate is no different from the behavior of one made from the

Answer 37

anhydrous form

Question 38

dissolving either form results in a system containing

Answer 38

hydrated ions and water

Question 39

ionic compounds are generally not soluble in

Answer 39

nonpolar solvents

Question 40

the nonpolar solvent molecules do not attract the ions of the crystal strongly enought to overcome the forces holding the

Answer 40

crystal together

Question 41

liquids that are not soluble in each other are

Answer 41

immiscible

Question 42

nonpolar substances are generally quite soluble in

Answer 42

nonpolar liquids

Question 43

the only attractions between the nonpolar molecules are

Answer 43

london forces

Question 44

the intermolecular forces existing in the solution are therefore very similar to those in

Answer 44

pure substances

Question 45

liquids that dissolve freely in one another in any proportion are said to be

Answer 45

miscible

Question 46

changes in pressure have very little effect on the solubilities of

Answer 46

liquids or solids in liquid solvents

Question 47

increases in pressure increas gas

Answer 47

solubilities in liquid

Question 48

when a gas is in contact with ther surface of a liquid, gas molecules can

Answer 48

enter the liquid

Question 49

as the amountof dissolved gas increases some molecules begin to escape and reenter the

Answer 49

gas phase

Question 50

an equilibrium is eventually established between the rates at which gas molecules enter and leave the

Answer 50

liquid phase

Question 51

as long as this equilibrium is undistrubed, the solutibility of the gas in the liquid is unchanged at a given

Answer 51

pressure

Question 52

gas + solvent ⇌

Answer 52

solution

Question 53

increasing the pressure of the solute gas above the solution puts stress on the

Answer 53

equilibrium

Question 54

molecules collide with the liquid surface more

Answer 54

often

Question 55

the increase in pressure is partially offset by an increase in the rate of gas molecules entering the

Answer 55

solution

Question 56

in turn the increase in the amount of dissolved gaas causes an increase in the rate at which molecules escape from the liquid surface and become

Answer 56

vapor

Question 57

eventually equilibrium is restored at a

Answer 57

higher gas solubility

Question 58

an increase in gas pressure casues the equilibirium to shift so that more molecules are in the

Answer 58

liquid phase

Question 59

the solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid:

Answer 59

henry's law

Question 60

henry's law applies to gas liquid solutions at

Answer 60

constant temperature

Question 61

when a mixture of ideal gases is confined in a constant volume at a constant temperature, each gas exerts the same pressure it would exert if it occupied the space

Answer 61

alone

Question 62

assuming that the gases do not react in any way, each gas dissolves to the extent it would dissolve if no other gases were

Answer 62

present

Question 63

the rapid escape of a gas from a liquid in which it is dissolved is known as

Answer 63

effervescence

Question 64

increasing temperature usually decreases

Answer 64

gas solubility

Question 65

as the temperature increases, the average kinetic energy of the molecules in solution

Answer 65

increases

Question 66

a greater number of solute molecules are able to escape from the attraction of solvent molecules and return to

Answer 66

the gas phase

Question 67

at higher temperatures, equilibrium is reached with fewer gas molecules in solution, and gases are generally less

Answer 67

soluble

Question 68

the effect of temperature on solubility of solids in liquids is more difficult to

Answer 68

predict

Question 69

often, increasing temp increases solubility of

Answer 69

solids

Question 70

however, an equibalent temp increase can result in a large increase in solubility for some solvents and onlyt a

Answer 70

slight change for others

Question 71

in some cases, solubility of a solid decreases with an

Answer 71

increase in temperature

Question 72

the formation of a solution is accompanied by an

Answer 72

energy change

Question 73

the formation of a solid liquid solution can apparently either absorb energy or

Answer 73

release enrgy as heat

Question 74

during the formation of a solution solvent and solute particles experience changes in the forces attracting them to other

Answer 74

particles

Question 75

befor3e dissolving begins solvent molecules are held together by

Answer 75

intermolecular forces (solvent solvent attaction_

Question 76

in the solute molecules are held together by

Answer 76

intermoelcular forces (solute solute attraction)(

Question 77

energy is requoired to separate solute molecules and solvent moecules from their

Answer 77

neightbors

Question 78

a solute particle that is surrounded by solvent molecules is said to be

Answer 78

solvated

Question 79

the net amount of energy absorved as heat by the solution when a specific amount of solute dissolves in a solvent is the

Answer 79

enthalpy of solution

Question 80

thyou know tghat heating decreases the solubility of a gas, so dissolution of gases is

Answer 80

exothermic

Question 81

in the gaseous state, molecules are so far apart that there are virtually no intermolecular forces of

Answer 81

attraction between them

Question 82

therefore the solute solute interaction has little effect on the

Answer 82

enthalpy of a solution of a gas

Question 83

energy is relreased when a gas dissolves in a liquid because attraction between solute gas and solvent molecules outweighs the energy needed to separatge

Answer 83

solevent molecules

Question 84

Enthalpy of solution is negative when energy is

Answer 84

Released

Question 85

Enthalpy of solution is positive when energy is

Answer 85

Absorbed

Question 86

Energy is absorbed when solute particles becoming

Answer 86

Separated from solid

Question 87

Energy is absorbed when solvent particles being moved apart to allow

Answer 87

Solute particles to enter liquid

Question 88

Energy being released when solvent particles being attracted to and

Answer 88

Solvating solute particles