Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 × 10-5 ) and 0.172 M sodium
1)
acetate is __________.
A) 9.92
B) 4.08
C) 8.37
D) 5.43
E) 8.57
2) Consider a solution containing 0.100 M fluoride ions and 0.126 M hydrogen fluoride. The
concentration of fluoride ions after the addition of 5.00 mL of 0.0100 M HCl to 25.0 mL of this
solution is __________ M.
A) 0.0817
B) 0.00167
C) 0.00253
D) 0.0850
E) 0.0980
3) Consider a solution containing 0.100 M fluoride ions and 0.126 M hydrogen fluoride. The
concentration of hydrogen fluoride after addition of 5.00 mL of 0.0100 M HCl to 25.0 mL of this
solution is __________ M.
A) 0.126
B) 0.00193
C) 0.100
D) 0.107
2)
3)
E) 0.00976
4) Calculate the pH of a solution prepared by dissolving 0.370 mol of formic acid (HCO2 H) and 0.230
4)
mol of sodium formate (NaCO2H) in water sufficient to yield 1.00 L of solution. The Ka of formic
acid is 1.77 × 10-4.
A) 10.46
B) 2.30
C) 3.95
D) 2.09
E) 3.54
5) Calculate the pH of a solution prepared by dissolving 0.250 mol of benzoic acid (C7 H5 O2 H) and
5)
0.150 mol of sodium benzoate (NaC7 H5 O2) in water sufficient to yield 1.00 L of solution. The Ka of
benzoic acid is 6.50 × 10-5.
A) 4.41
B) 2.39
C) 10.0
D) 4.19
E) 3.97
6) A 25.0 mL sample of an HCl solution is titrated with a 0.139 M NaOH solution. The equivalence
point is reached with 15.4 mL of base. The concentration of HCl is __________ M.
A) 0.0856
B) 0.139
C) 0.00214
D) 0.267
E) 11.7
7) The concentration of iodide ions in a saturated solution of lead (II) iodide is __________ M. The
solubility product constant of PbI2 is 1.4 × 10-8.
A) 3.0 × 10-3
B) 3.8 × 10-4
C) 1.5 × 10-3
D) 3.5 × 10-9
B) 5.0 × 10-4
C) 1.6 × 10-2
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D) 1.6 × 10-5
7)
E) 1.4 × 10-8
8) The solubility of lead (II) chloride (PbCl2) is 1.6 × 10-2 M. What is the Ksp of PbCl2 ?
A) 4.1 × 10-6
6)
8)
E) 3.1 × 10-7
9) Which one of the following pairs cannot be mixed together to form a buffer solution?
9)
A) NH3, NH4 Cl
B) RbOH, HBr
C) NaC2H3O2 , HCl (C2 H3O2 - = acetate)
D) H3 PO4, KH2 PO4
E) KOH, HF
10) A solution containing which one of the following pairs of substances will be a buffer solution?
10)
A) NaI, HI
B) CsF, HF
C) KBr, HBr
D) RbCl, HCl
E) none of the above
11) What change will be caused by addition of a small amount of HCl to a solution containing fluoride
ions and hydrogen fluoride?
11)
A) The concentration of hydrogen fluoride will decrease and the concentration of fluoride ions
will increase.
B) The concentration of fluoride ion will decrease and the concentration of hydrogen fluoride
will increase.
C) The fluoride ions will precipitate out of solution as its acid salt.
D) The concentration of hydronium ions will increase significantly.
E) The concentration of fluoride ions will increase as will the concentration of hydronium ions.
12) Of the following solutions, which has the greatest buffering capacity?
12)
A) They are all buffer solutions and would all have the same capacity.
B) 0.821 M HF and 0.217 M NaF
C) 0.100 M HF and 0.217 M NaF
D) 0.121 M HF and 0.667 M NaF
E) 0.821 M HF and 0.909 M NaF
13) The addition of hydrofluoric acid and __________ to water produces a buffer solution.
A) NaNO3
B) HCl
C) NaF
D) NaCl
2
E) NaBr
13)
14) Which of the following could be added to a solution of sodium acetate to produce a buffer?
acetic acid
hydrochloric acid
potassium acetate
14)
sodium chloride
A) sodium chloride or potassium acetate
B) acetic acid or hydrochloric acid
C) hydrochloric acid only
D) potassium acetate only
E) acetic acid only
15) In which of the following aqueous solutions would you expect AgBr to have the lowest solubility?
15)
A) 0.10 M LiBr
B) pure water
C) 0.15 M KBr
D) 0.10 M AgNO3
E) 0.20 M NaBr
16) In which of the following aqueous solutions would you expect AgBr to have the highest solubility?
16)
A) 0.20 M NaBr
B) 0.10 M AgNO3
C) 0.10 M LiBr
D) pure water
E) 0.15 M KBr
17) In which of the following aqueous solutions would you expect PbCl2 to have the lowest solubility?
17)
A) pure water
B) 0.020 M KCl
C) 0.020 M BaCl2
D) 0.015 M PbNO3
E) 0.015 M NaCl
18) In which one of the following solutions is silver chloride the most soluble?
A) pure water
B) 0.0176 M LiNO3
C) 0.0181 M HCl
D) 0.744 M LiNO3
E) 0.181 M NaCl
3
18)
19) A solution is prepared by dissolving 0.23 mol of chloroacetic acid and 0.27 mol of sodium
chloroacetate in water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of HCl to this
buffer solution causes the pH to drop slightly. The pH does not decrease drastically because the
HCl reacts with the __________ present in the buffer solution. The Ka of chloroacetic acid is 1.36 ×
19)
10-3.
A) This is a buffer solution: the pH does not change upon addition of acid or base.
B) H2 O
C) chloroacetic acid
D) H3 O+
E) chloroacetate ion
20) A 25.0 mL sample of 0.150 M nitrous acid is titrated with a 0.150 M NaOH solution. What is the pH
at the equivalence point? The Ka of nitrous acid is 4.50 × 10-4.
A) 8.11
B) 10.35
C) 3.35
D) 10.65
E) 7.00
21) A 25.0 mL sample of an acetic acid solution is titrated with a 0.175 M NaOH solution. The
equivalence point is reached when 37.5 mL of the base is added. The concentration of acetic acid is
__________ M.
A) 0.263
B) 0.119
C) 0.365
D) 0.175
E) 1.83 × 10-4
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20)
21)