chapter 13 (exam 2)

Question 1

solution

Answer 1

-homogeneous mixture made of 2 or more different chemical substances in the SAME phase
-made of solvent and solute

Question 2

solvent

Answer 2

the substance in the solution that in the LARGEST amount
-longer name, larger amount

Question 3

if it solution is (aq)

Answer 3

the solvent is water

Question 4

solute

Answer 4

the substance in the SMALLER amount
-smaller name, smaller amount

Question 5

if one of the substances is a liquid and all the others are solids or gases…

Answer 5

the liquid would be the solvent, not matter how much of it there is

Question 6

solution formation is a result from IMFs of the solute and solvent which shows

Answer 6

-miscible, “like dissolves like”
-polar with polar and non polar with non polar

Question 7

nature usually has spontaneous mixing, but uniform mixing is

Answer 7

more energetically favorable

Question 8

dilute solution

Answer 8

contains SMALL quantities of solute relative to the amount of solvent

Question 9

concentrated solution

Answer 9

contains LARGE quantities of solute relative to the amount of solvent

Question 10

molarity equation

Answer 10

M= moles solute/solution volume (L)

Question 11

molality equation

Answer 11

m= moles solute/ mass of solvent (kg)

Question 12

mass percent

Answer 12

%m/m= (mass solute)/ (total mass solution) x100%

Question 13

parts per million

Answer 13

ppm= mass solute (g)/ mass solution (g) x10^6

Question 14

volume percent

Answer 14

%v/v= (vol solute/ vol solution) x100%

Question 15

mole fraction

Answer 15

Xa= moles of component A/ total moles in solution

Question 16

mass solution =

Answer 16

mass solute + mass solvent

Question 17

solubility

Answer 17

the amount of a substance that will dissolve in a given amount of a solvent

Question 18

solubility of a substance depends on

Answer 18

-entropy (tendency to spontaneous mixing)
- types of IMFs

Question 19

a solution will form solvent-solute interactions that are

Answer 19

comparable or stronger than the solvent-solvent or solute-solute interactions

Question 20

when the solvent-solute interactions are weaker than the sum of the solute-solute and solvent-solvent interactions…

Answer 20

the solution can only form if the energy difference is small enough to be overcome by and increase in entropy

Question 21

if solvent-solute > solvent-solvent and solute solute

Answer 21

solution forms

Question 22

if solvent-solute < solvent-solvent and solute solute

Answer 22

solution may or may not form depending on the disparity

Question 23

if solvent-solute = solvent-solvent and solute solute

Answer 23

solution will form

Question 24

formation of a solution step 1

Answer 24

1) solute separated into its constituent parts
- the ΔH solute > 0

Question 25

formation of a solution step 2

Answer 25

2) solvent particles are separated from each other to make room for solute particles - the ΔH solvent > 0

Question 26

formation of a solution step 3

Answer 26

3) the solute particles and solvent particles are mixed together - the ΔH mix < 0

Question 27

ΔH solution

Answer 27

ΔH solute(+) + Δ H solvent(+) + ΔH mixing(-)

Question 28

if ΔH solution is < 0

Answer 28

exothermic -releases heat

Question 29

if ΔH solution > 0

Answer 29

endothermic -absorbs heat

Question 30

in some cases, solution formation with small positive or negative enthalpy of solution the

Answer 30

entropic contributions dominate and the solution forms easily -the ΔG < 0

Question 31

in some cases, the enthalpy of solution is expected to be large positive or negative the

Answer 31

the entropic contribution is too small to overcome the enthalpy so the solution will not form -the ΔG > 0

Question 32

enthalpy of solvation

Answer 32

energy difference btw a free ion and the solvated ion

Question 33

enthalpy of hydration

Answer 33

when solvent is water -the heat released when 1 mole of gas ions dissolves in water

Question 34

the enthalpy of hydration is _____ for ionic compounds

Answer 34

always large and exothermic

Question 35

ΔH hydration=

Answer 35

ΔH solvent + ΔH mixing

Question 36

as the attraction btw solvent particles and the ion increases

Answer 36

the enthalpy of hydration becomes more exothermic

Question 37

larger ion charge and small ionic radius leads to a

Answer 37

stronger attraction -more exothermic enthalpy of hydration

Question 38

ΔH solution =

Answer 38

ΔH hydration - ΔH lattice energy

Question 39

when the absolute value of ΔH solute < ΔH hydration --->

Answer 39

ΔH solution <0 -increase in temp so container feels hot

Question 40

when the absolute value of ΔH solute > ΔH hydration --->

Answer 40

ΔH solution >0 - decrease in temp so container feels cold

Question 41

when the absolute value of ΔH solute = ΔH hydration --->

Answer 41

ΔH solution = 0 -no noticeable change

Question 42

stage one of solution equilibrium

Answer 42

-solution process starts by solute particles surrounded by the solvent particles -solute particles decrease over time

Question 43

solution equilibrium stage 2

Answer 43

-at some point, there's high enough concentration of solute particles in solution and they will precipitate when they bump into each other

Question 44

solution equilibrium stage 3

Answer 44

-the rate of dissolution (dissolving) = rate of recrystallization (precipitation) -solution is at dynamic equilibrium

Question 45

saturated

Answer 45

solution has the solute and the solvent in dynamic equilibrium

Question 46

saturated solution

Answer 46

-solution containing the max amount of dissolved solute at equilibrium

Question 47

if you add more solute to a saturated solution

Answer 47

it will not dissolve -the solution concentration won't change at that temp

Question 48

supersaturated

Answer 48

solution has more solute than saturated is said to be -must be heated, dissolved, then cooled down

Question 49

unsaturated

Answer 49

solution has less solute than saturation is said to be

Question 50

supersaturated solutions are ___ and excess solute normally___

Answer 50

-unstable -precipitated out of solution

Question 51

when a solution is saturated

Answer 51

-its at dynamic equilibrium -net rate of dissolution of solute is zero -net rate of precipitation of solute is zero

Question 52

as temperature increases (sol)

Answer 52

solubility usually increases -depends on the enthalpy of solution

Question 53

if ΔH solution < 0 (exothermic) has its temp decreased

Answer 53

the solubility increases

Question 54

if ΔH solution > 0 (endothermic) has its temp increased

Answer 54

the solubility increases

Question 55

solubility of gases in liquids decreases with increasing

Answer 55

temperature

Question 56

henry's law

Answer 56

as the pressure of a gas increases, the solubility of the gas increases

Question 57

S/ Cg=

Answer 57

kH Pgas