Sample Acid/Base, Buffer, Ksp Problems
Use the following information and answer questions 1-6:
Species
HC2H3O2
HClO2
HNO2
HCN
Ka
1.8 x 10-5
1.2 x 10-2
4.0 x 10-4
6.2 x 10-10
1. Rank the following 0.100 M solutions from most acidic to most basic (left to right):
C2H3O2-, HCl, HNO2, CN-, NaCl
A)
B)
C)
D)
E)
2.
HCl, HNO2, NaCl, C2H3O2-, CNHCl, NaC, HNO2, C2H3O2-, CNCN-, HCl, HNO2, NaCl, C2H3O2NaCl, HNO2, HCl, C2H3O2-, CNCN-, C2H3O2-, NaCl, HNO2, HCl
If you were interested in making a buffer at pH 3.8. Which acid/conjugate base pair would you use?
A)
B)
C)
D)
E)
HCl/ClHC2H3O2/ C2H3O2HNO2/NO2HClO2/ClO2HCN/CN-
3. A 0.100 M solution of which weak acid will have a pH of 1.46?
A)
B)
C)
D)
E)
HCl
HC2H3O2
HClO2
HNO2
HCN
4. What is the pH of a solution that is 0.100 M in both HClO 2 and NaClO2?
A)
B)
C)
D)
E)
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7.00
1.00
1.92
12.08
1.46
5. 50.0 mL of a 0.0500 M solution of HNO2 is titrated with 0.100 M NaOH. What is the pH of the solution at
equivalence?
A)
B)
C)
D)
E)
7.00
6.04
7.96
2.44
8.52
6. What pH does a solution of 0.100 M HCN have to be in order to have equal amounts of the acid and conjugate
base present at equilibrium?
A)
B)
C)
D)
E)
9.21
7.00
4.79
5.10
8.90
7. 50.0 mL of a 0.050 M solution of HBr is titrated with 20.0 mL of 0.100 M KOH. What is the pH of the
solution?
A)
B)
C)
D)
E)
1.30
1.45
2.00
2.15
7.00
8. Which of the following solutions will be acidic?
A)
B)
C)
D)
E)
0.050 M NH3
0.100 M NaCl
0.025 M NaNO3
0.100 M CrCl3
0.200 M Ca(OH)2
9. Determine the Ksp of Bi2S3 for which the solubility is 1.0 x 10-15 M at 298 K.
A)
B)
C)
D)
E)
1.0 x 10-15
1.0 x 10-30
6.0 x 10-30
1.1 x 10-73
1.0 x 10-75
10. What Ag+ concentration will result when solid Ag2SO4 (Ksp = 1.2 x 10-5) is placed in water?
A)
B)
C)
D)
E)
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0.029 M
0.014 M
0.0035 M
1.4 x 10-10 M
1.0 x 10-5 M
11. A solution contains 0.36 M HA (Ka = 2.0 x 10-7) and 0.24 M NaA. Calculate the pH after 0.04 mol of NaOH is
added to 1.00 L of this solution?
A)
B)
C)
D)
E)
6.76
6.52
6.64
6.40
6.70
12. Which of the following will not produce a buffered solution?
A)
B)
C)
D)
E)
100 mL of 0.1 M Na2CO3 and 50 mL of 0.1 M HCl
100 mL of 0.1 M NaHCO3 and 25 mL of 0.2 M HCl
100 mL of 0.1 M Na2CO3 and 75 mL of 0.2 M HCl
50 mL of 0.2 M Na2CO3 and 5 mL of 0.1 M HCl
100 mL of 0.1 M Na2CO3 and 50 mL of 0.1 M NaOH
13. In which solution would hypochlorous acid have the highest percent ionization?
A)
B)
C)
D)
E)
0.15 M potassium hypochlorite
0.25 M hydrochloric acid
0.10 M lithium hypochlorite
0.20 M magnesium chloride
none of the above
14. In which of the following solutions would lead iodide have the highest solubility?
A)
B)
C)
D)
E)
0.17 M sodium iodide
0.47 M lead nitrate
0.20 M lithium chloride
0.30 M lead acetate
0.11 M ammonium iodide
15. What solid will precipitate first if an aqueous solution of sodium chromate at 25°C is slowly added to an
aqueous solution containing 0.100 M lead nitrate and 0.100 M barium nitrate at 25°C?
Ksp (BaCrO4) = 2.1 x 10-10, Ksp (PbCrO4) = 1.8 x 10-14?
A)
B)
C)
D)
E)
Ba(NO3)2(s)
BaCrO4(s)
NaNO3(s)
PbCrO4 (s)
none of the above
16. Copper(II) oxalate is only slightly soluble in water, having K sp = 2.9 x 10-8 at 25°C. This means that the
solubility of CuC2O4 in water at 25°C is.
A) 1.1  10-5 M
B) 1.5  10-5 M
C) 8.6  10-5 M
D) 1.7  10-4 M
E) none of the above
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Useful Information
(a clearer periodic table will be provided)
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