AP chem
Text: chapter 11
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Review - 8
(Solutions)
M = mol/L
m = mol/kg
χa = na/nT
o
Psoln = χsolvP solv (nonvolatile solute)
PROBLEMS
1. A solution is prepared by dissolving
1.25 g of an unknown substance in
100.0 mL of water. Which
procedure could be used to find if
the solute is an electrolyte?
a. Measure the specific heat of
the solution.
b. Measure the volume of the
solution.
c. Measure the freezing point of
the solution.
d. Determine the specific heat of
the solution.
e. Determine the volume of the
solute.
2.
3.
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Strontium sulfate will precipitate
when a solution of sodium sulfate is
added to a strontium nitrate
solution. What will be the strontium
2+
ion, Sr , concentration remaining
after 30.0 mL fo a 0.10 M Na2SO4
solution are added to 70.0 mL of
0.20 M Sr(NO3)2 solution?
a. 0.14 M
b. 0.15 M
c. 0.11 M
d. 0.20 M
e. 0.030 M
4.
Which is a strong electrolyte?
a. HNO2(aq)
b. KNO3(aq)
c. C2H5OH(aq)
d. CH3COOH(aq)
e. NH3(aq)
5.
A solution with a total chloride ion,
Cl , concentration of 1.0 M is
needed. Initially, the solution is
0.30 M in MgCl2. How many moles
of solid CaCl2 must be added to 400
mL of the MgCl2 solution to yield the
desired concentration of chloride?
a. 0.10
b. 0.080
c. 0.20
d. 0.15
e. 0.16
Psoln = χaP
ΔT = iKm
π = iMRT
o
a
+ χ bP
6.
Assuming the volumes are additive,
+
what is the final H concentration
after mixing 30.0 mL of 0.50 M
HNO3 with 70.0 mL of 1.00 M HCl?
a. 0.75 M
b. 1.50 M
c. 1.25 M
d. 0.85 M
e. 0.43 M
7.
The molality of a 1.0-M ethyl
alcohol solution may be determined
if which of the following is supplied?
a. density of solution
b. van’t Hoff factor for ethyl
alcohol
c. temperature of the solution
d. volume of the solution
e. solubility of ethyl alcohol
+
What is the final [K ] in a solution
made by mixing 300 mL of 1.0 M
KNO3 and 700 mL of 2.0 M K3PO4?
a. 1.5 M
b. 5.0 M
c. 3.0 M
d. 2.0 M
e. 4.5 M
Name: ____________________
8.
9.
A solution of chloroform, CHCl3, in
carbon tetrachloride, CCl4, is nearly
ideal. The vapor pressure of
o
chloroform is 170 mmHg at 20 C,
and the vapor pressure of carbon
tetrachloride is 87 mmHg at this
temperature. What is the mole
fraction of carbon tetrachloride in
the vapor over an equimolar
solution of these two liquids?
a. 0.25
b. 0.87
c. 0.66
d. 0.50
e. 0.34
To prepare 3.0 L of a 0.20 M K3PO4
solution (MW = 212), a student
should follow which of the following
procedures?
a. The student should weigh 42 g
of solute and add sufficient
water to obtain a final volume
of 3.0 L.
b. The student should weigh out
42 g of solute and add 3.0 kg
of water.
c. The student should weigh 130
g of solute and add sufficient
water to obtain a final volume
of 3.0 L.
d. The student should weigh 42 g
of solute and add 3.0 L of
water.
e. The student should weigh 130
g of solute and add 3.0 L of
water.
o
b
(volatile solute)
10. A 5.2 m solution of CH3OH(aq) is
supplied. What is the mole fraction
of methyl alcohol in this solution?
a. 0.10
b. 0.19
c. 0.086
d. 0.050
e. 0.094
11. Which has the highest boiling pt?
a. 0.10 M HI(aq)
b. 0.10 M (NH4)3PO4(aq)
c. 0.20 M C2H5OH(aq)
d. 0.10 M NH4Cl(aq)
e. 0.10 M NaI(aq)
12. How many grams of MgSO4 are in
100.0 mL of a 5.0 M solution?
a. 600 g
b. 5.0 g
c. 12 g
d. 60.0 g
e. 120 g
13. How many mL of concentrated nitric
acid (16.0 M HNO3) are needed to
prepare 0.500 L of 6.0 M HNO3?
a. 0.19 mL
b. 250 mL
c. 375 mL
d. 190 mL
e. 100 mL
14. When using the freezing-point
depression method to find the molar
mass of a nonelectrolyte, what is
needed in addition to the following?
ž the freezing point constant, Kf
ž the freezing point of pure solvent
ž the freezing point of the solution
a. the mass of the solute
b. the volume of the solvent and
the mass of the solute
c. the mass of the solvent and the
boiling point of the solvent
d. the mass of the solvent and the
mass of the solute
e. no more information is needed
15. A solution has a mole fraction of
0.20 of CHCl3 in CCl4. What is the
molality of chloroform?
a. 1.7 m
b. 0.17 m
c. 0.20 m
d. 1.3 m
e. 1.20 m
© S. O’Malley 2012
16. A solution is 10% urea by mass.
Which item(s) are needed to find
the molarity of this solution?
i. the density of the solution
ii. the density of the solvent
iii. the molecular weight of urea
a. i and iii
b. i only
c. ii only
d. iii only
e. i and ii
17. Which of the following solutions has
the greatest ΔTf?
a. 0.10 m (NH4)2SO4(aq)
b. 0.10 m MnSO4(aq)
c. 0.10 m NaF(aq)
d. 0.10 m KCl(aq)
e. 0.10 m CH3OH(aq)
18. Which solution has the greatest
conductivity?
a. 0.2 M NaOH
b. 0.2 M RbCl2
c. 0.2 M NH4NO3
d.
e.
0.2 M HNO2
0.2 M K3PO4
19. An aqueous solution of KNO3 is
o
o
cooled from 75 C to 15 C. Which
statement is true?
a. The molarity of the solution
does not change.
b. The molality of the solution
decreases.
c. The density of the solution
does not change.
d. The molality of the solution
does not change.
e. The mole fraction of the solute
increases.
20. How many milliliters of water must
be added to 50.0 mL of 10.0 M
HNO3 to prepare 4.00 M HNO3?
a. 50.0 mL
b. 125 mL
c. 500 mL
d. 250 mL
e. 75.0 mL
21. Pick the pair of substances that will
most likely obey Raoult’s law.
a. CH3CH2CH2CH2COOH and
C5H12
b. C5H12 and H2O
c. CH3CH2CH2CH2COOH and
H 2O
d. H3PO4 and H2O
e. C5H12 and C6H14
22. The best method to isolate pure
MgSO4 from MgSO4(aq) is
a. Evaporate the solution to
dryness.
b. Titrate the solution.
c. Electrolyze the solution.
d. Use paper chromatography.
e. Filter the solution.
23. Which conditions yield the highest
concentration of N2(g) in water?
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a. Pgas = 1.0 atm, T = 25 C
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b. Pgas = 0.5 atm, T = 55 C
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c. Pgas = 2.0 atm, T = 25 C
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d. Pgas = 2.0 atm, T = 85 C
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e. Pgas = 1.0 atm, T = 85 C
FREE-RESPONSE
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24. Five beakers each containing 100.0 mL of an aqueous solution are placed on a lab bench. The solutions are all at 25 C.
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Solution 1 contains 0.20 M KNO3.
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Solution 2 contains 0.10 M BaCl2.
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Solution 3 contains 0.15 M C2H4(OH)2.
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Solution 4 contains 0.20 M (NH4)2SO4.
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Solution 5 contains 0.25 M KMnO4.
a. One of the solutions could oxidize two of the other solutions. Which solution is it? Which solutions could it oxidize?
b.
Which solution has the lowest pH? Explain.
c.
Which pair of solutions would give a precipitate if they are mixed? What is the formula for this precipitate?
d.
Which solution would be the poorest conductor of electricity? Explain.
e.
Rank the solutions in order of increasing boiling point. Explain.
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1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
C
E
C
B
B
D
A
E
C
C
B
D
D
D
A
A
A
E
D
E
E
A
C
25. Five beakers at 25 C are placed in a row on a countertop. Each beaker is half filled with a 0.20 M aqueous solution. The
solutes, in order, are:
(1) potassium sulfate
(2) methyl alcohol
(3) sodium carbonate
(4) ammonium chromate
(5) barium chloride.
a. Which solution will form a precipitate when ammonium chromate is added to it? Give the formula of the precipitate.
b.
Which solution is the most basic? Explain.
c.
Which solution will exhibit the lowest boiling point elevation? Explain.
d.
Which solution is colored?
e.
Which of the other solutions will not react with solution (5)?
Problems taken from “5 Steps to a 5”, McGraw Hill
24.
a. solution 5, solutions 2 and 3
b. solution 4, NH4+ is a weak acid and undergoes hydrolysis
c. solutions 2 and 4, BaSO4
d. solution 3, it is a non-electrolyte
e. 3 < 2 < 1 < 5 < 4; number of particles increases
25.
a. (5), BaCrO4
b. (3), Na2CO3 is a basic salt in solution
c. (2), CH3OH is a non-electrolyte and does not dissociate
d. (4), (NH4)2CrO4 is yellow
e. (2), CH3OH will not react with BaCl2