Name ________________________________________ Class _________________ Date _______________
PROPERTIES OF SOLUTIONS
18.1
SECTION REVIEW
Objectives
• Identify the factors that determine the rate at which a solute dissolves
• Calculate the solubility of a gas in a liquid under various pressure conditions
Key Terms
• saturated solution
• solubility
• unsaturated
• miscible
• immiscible
• Henry’s law
• supersaturated solution
Key Equation
S
P1
S
P2
• Henry’s law: }}1 5 }}2
Part A Completion
Use this completion exercise to check your understanding of the concepts and terms
that are introduced in this section. Each blank can be completed with a term, short
phrase, or number.
Changes in the temperature of a system and
solute alter the
2
1
of a
1.
at which a solute dissolves. The extent
2.
to which a gas dissolves in a liquid is proportional to the
of the gas in accordance with
Prentice Hall, Inc. All rights reserved.
decreases with
5
4
3
3.
law. The solubility of a gas
temperature. A solution that contains the
maximum amount of solute at a given temperature is said to be
6
9
A
7
. Generally the
8
of a solid in water
7.
8.
with increasing temperature, but there are exceptions.
10
5.
6.
. Two liquids that are mutually soluble in each other are
said to be
4.
9.
solution holds more solute than theoretically possible.
10.
Part B True-False
Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT.
________ 11. The rate at which a solute dissolves can be increased by grinding.
Review Module / Chapters 17–20
31
Name ________________________________________ Class _________________ Date _______________
________ 12. As the temperature of a solvent decreases, the solubility of a solute
increases.
________ 13. Stirring a solute when adding it to a solvent should increase the rate of
its dissolving.
________ 14. Henry’s law states that the solubility of a gas in a liquid is a function of
temperature.
________ 15. Two liquids which dissolve in each other are miscible.
Part C Matching
Match each description in Column B to the correct term in Column A.
Column B
________ 16. saturated solution
a. the amount of a substance that dissolves in a given quantity
of solvent at a given temperature
________ 17. solubility
b. The solubility of a gas in a liquid is directly proportional to
the pressure of the gas above the liquid.
________ 18. unsaturated
c. solution that contains the maximum amount of solute for a
given amount of solvent at a constant temperature
________ 19. miscible
d. a solution containing more solute than it can theoretically
hold at a given temperature
________ 20. immiscible
e. description of two liquids that dissolve in each other
________ 21. Henry’s law
f. a solution that contains less solute than possible at a given
temperature
________ 22. supersaturated
solution
g. description of two liquids that do not dissolve in each other
Part D Questions and Problems
Solve the following problem in the space provided. Show your work.
23. The solubility of a gas in water is 1.6 g/L at 1.0 atm of pressure. What is the
solubility of the same gas at 2.5 atm? Assume the temperature to be constant.
32
Review Module / Chapters 17–20
Prentice Hall, Inc. All rights reserved.
Column A
Name ________________________________________ Class _________________ Date _______________
18.2
CONCENTRATIONS OF SOLUTIONS
SECTION REVIEW
Objectives
• Solve problems involving the molarity of a solution
• Describe how to prepare dilute solutions from more concentrated solutions of
known molarity
• Explain what is meant by percent by volume [%(v/v)] and percent by mass
[%(m/v)] solutions
Key Terms
• concentration
• dilute solution
• concentrated solution
• molarity (M)
Key Equations
moles of solute
liters of solution
M1 3 V1 5 M2 3 V2
volume of solute
Percent by volume [%(v/v)] 5 }} 3 100%
solution volume
mass of solute (g)
Percent (mass/volume)[%(m/v)] 5 }}} 3 100%
solution volume (mL)
• Molarity (M) 5 }}
•
•
•
Part A Completion
Use this completion exercise to check your understanding of the concepts and terms
that are introduced in this section. Each blank can be completed with a term, short
phrase, or number.
Prentice Hall, Inc. All rights reserved.
The relative amounts of solute and
3
be described qualitatively as
1
2
in a
can
or concentrated. Quantitative
1.
2.
units of concentration include molar concentration, percent by
3.
volume, and percent (mass/volume).
4.
Molarity, the most important unit of concentration in
chemistry, is expressed as
4
of solute per
5
5.
of solution. 6.
Solutions of different concentrations can be prepared by
6
a stock solution. In dilution, the moles of
the same, while the amount of
8
7
7.
remain
8.
changes.
Review Module / Chapters 17–20
33
Name ________________________________________ Class _________________ Date _______________
Part B True-False
Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT.
________ 9. One hundred mL of 1.0M sodium hydroxide solution is more
concentrated than 1.0 L of 5M sodium hydroxide solution.
________ 10. The amount of sodium hydroxide in 100 mL of 1.0M NaOH is less than
that in 1.0 L of 5M NaOH solution.
________ 11. Fifty mL of a 32% solution (v/v) of ethyl alcohol in water would
contain 42 mL of water.
________ 12. A dilute solution is a quantitative expression of concentration.
Part C Matching
Match each description in Column B to the correct term in Column A.
Column A
Column B
________ 13. concentration
a. number of moles of solute dissolved in 1 L of solution
________ 14. dilute solution
b. measure of the amount of solute that is dissolved in a
given quantity of solvent
________ 15. concentrated solution
c. solution that contains a low concentration of solute
________ 16. molarity
d. concentration expressed as volume or mass of solute
over volume of solution 3 100%
________ 17. percent solution
e. solution that contains a high concentration of solute
Part D Questions and Problems
18. What mass of sucrose, C12H22O11, is needed to make 300.0 mL of a
0.50M solution?
34
Review Module / Chapters 17–20
Prentice Hall, Inc. All rights reserved.
Solve the following problem in the space provided. Show your work.
Name ________________________________________ Class _________________ Date _______________
COLLIGATIVE PROPERTIES OF SOLUTIONS
18.3
SECTION REVIEW
Objectives
• Explain on a particle basis why a solution has a lower vapor pressure than the
pure solvent of that solution
• Explain on a particle basis why a solution has an elevated boiling point and a
depressed freezing point compared with the pure solvent
Key Terms
• colligative properties
• boiling-point elevation
• freezing-point depression
Part A Completion
Use this completion exercise to check your understanding of the concepts and terms
that are introduced in this section. Each blank can be completed with a term, short
phrase, or number.
1
The effects in solution of a nonvolatile
properties of the solvent are called
point and vapor pressure
4
2
on the
3
2.
. In
3.
proportional to
4.
. They include
, and boiling point
each case, the magnitude of the effect is
6
1.
5
the number of solute molecules or ions present in the
7
.
5.
Colligative properties are a function of the number of solute
Prentice Hall, Inc. All rights reserved.
8
in solution. For example, one mole of sodium chloride
produces
9
as many particles in solution as one mole of
sucrose and, thus, will depress the freezing point of water
as much.
10
6.
7.
8.
9.
10.
Part B True-False
Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT.
________ 11. When added to 1000 g of water, 2 moles of a solute will increase the
boiling point by 0.512 8C.
________ 12. One mole of solute A will depress the freezing point of 1000 g of water
the same as one mole of solute B.
Review Module / Chapters 17–20
35
Name ________________________________________ Class _________________ Date _______________
________ 13. Addition of a nonvolatile solute will lower the boiling point of a
solvent.
________ 14. Addition of a nonvolatile solute will lower the freezing point of a solvent.
Part C Matching
Match each description in Column B to the correct term in Column A.
Column A
Column B
________ 15. colligative properties
a. difference between the freezing point of a solution
and the freezing point of the pure solvent
________ 16. boiling-point elevation
b. pressure exerted by a vapor that is in equilibrium
with its liquid in a closed system
________ 17. freezing-point depression
c. difference between the boiling point of a solution
and the boiling point of the pure solvent
________ 18. vapor pressure
d. properties of solutions that depend only on the
number of particles in solution
Part D Questions and Problems
Answer the following questions in the space provided.
19. How many moles of solute particles are produced by adding one mole of each
of the following to water?
a. sodium nitrate
b. glucose
d. potassium iodide
20. An equal number of moles of NaCl and K2CO3 are dissolved in equal volumes of
water. Which solution has the higher
a. boiling point?
b. vapor pressure?
c. freezing point?
36
Review Module / Chapters 17–20
Prentice Hall, Inc. All rights reserved.
c. aluminum chloride
Name ________________________________________ Class _________________ Date _______________
18.4
CALCULATIONS INVOLVING COLLIGATIVE PROPERTIES
SECTION REVIEW
Objectives
• Calculate the molality and mole fraction of a solution
• Calculate the molar mass of a molecular compound from the freezing-point
depression or boiling-point elevation of a solution of the compound
Key Terms
• molality (m)
• mole fraction
• molal boiling-point
• molal freezing-point
elevation constant (Kb)
depression constant (Kf)
Key Equations
moles of solute
kilogram of solvent
moles of solute
1000 g of solvent
• Molality 5 }}} 5 }}
n
nB
A
• mole fractions: XA 5 }
n 1}
n
A
XB 5 }
n 1}
n
B
A
where nA 5 moles of solute
nB 5 moles of solvent
B
• DTb 5 Kb 3 m
• DTf 5 Kf 3 m
Part A Completion
Use this completion exercise to check your understanding of the concepts and terms
that are introduced in this section. Each blank can be completed with a term, short
phrase, or number.
Molality is an expression of concentration involving the ratio
1
Prentice Hall, Inc. All rights reserved.
of
2
particles to
moles of solute per
3
particles. Molality is expressed as
of solvent.
1.
2.
3.
Another expression of concentration is
4
, in which
4.
concentrations are expressed as the ratio of moles of solute to the
5.
total number of moles of solvent and solute. Each solvent has a
6.
characteristic
6
5
elevation constant and molal freezing-point
constant. The elevation in boiling point of a solution can
7
be calculated by multiplying the
solution by the boiling-point
8
7.
8.
concentration of the
constant of the solvent.
Review Module / Chapters 17–20
37
Name ________________________________________ Class _________________ Date _______________
Part B True-False
Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT.
________ 9. It is possible to calculate the molar mass of a solute if you know the
Kb or Kf of a solvent.
________ 10. Molal concentration is the same as molar concentration.
________ 11. The depression in freezing point of a solution is proportional to the
molal concentration of solute.
________ 12. The sum of XA and XB for any solution is always 1.
Part C Matching
Match each description in Column B to the correct term in Column A.
Column A
Column B
________ 13. molality
a. a constant for a given solvent equal to the change in
boiling point for a 1m solution
________ 14. mole fraction
b. number of moles of solute dissolved in 1 kilogram of
solvent
________ 15. molal boiling-point
elevation constant
c. mass of one mole of a substance
________ 16. molal freezing-point
depression constant
d. a constant for a given solvent equal to the change in
freezing point for a 1m solution
________ 17. molar mass
e. ratio of moles of solute in solution to the total number
of moles of solute and solvent
Solve the following problem in the space provided. Show your work.
18. What is the freezing point of a solution that contains 2.0 mol of CaCl2 in 800.0 g
of water? Kf for water 5 1.86 8C/m
38
Review Module / Chapters 17–20
Prentice Hall, Inc. All rights reserved.
Part D Questions and Problems