Analytical Chemistry CC

Multiple Choice. Answer in letter only.

1. Which of the following statements is true?

A. When water freezes, the volume increases and thus the density decreases
B. When water freezes, the volume decreases and thus the density increases.
C. When water freezes, the volume decreases and thus the density decreases
D. When water freezes, the volume increases and thus the density increases.
2. The normal boiling point of a liquid is
A. 373 K.
B. the temperature at which a liquid's vapor pressure equals 1 atm.
C. the pressure at which the liquid boils at 373 K.
D. dependent upon the volume of the liquid.
E. dependent upon the surface area of the liquid..
3. What type of solid is generally soluble in nonpolar solvents?
A. metallic B. ionic C. molecular D. crystalline E. covalent
4. Which of the following processes is/are endothermic?
1. the combustion of hydrogen 2. the condensation of water 3. the evaporation of isopropyl alcohol
A. 1 only B. 2 only C. 3 only D. 1 and 3 E. 1, 2, and 3
Solutions and Colligative Properties
5. Which of the following is not an acceptable way of expressing concentration?
A. Mass of solute/volume of solution
B. Mass of solute/mass of solution
C. Mass of solute/100 g of water
D. Volume of solute/volume of solution
6 A student adds 6.00 g of a solid to 30.0 mL of water. What is the concentration of this solution
expressed as mass/volume percent? (If necessary to the calculation, assume that 1.00 mL of
water has a mass of 1.00 g and that the total volume remains 30.0 ml.)
A. 0.200% B. 16.7 % C. 20.0% D. 500 %
7. A student adds 6.00 g of a solid to 30.0 mL of water. What is the concentration of this solution
expressed as mass/mass percent? (Assume the volume of the solution remains 30.0 mL and, if
necessary to the calculation, assume that 1.00 mL of water has a mass of 1.00 g.)
A. 0.167 % (m/m) B. 0.200 %(m/m) C. 16.7 % (m/m) D. 20.0 %
8. A student adds 6.00 g of a solid to 30.0 mL of water. The solid has a molar mass of 72.0 g/mol.
What is the molar concentration of the solution? (If necessary to the calculation, assume that
1.00 mL of water has a mass of 1.00g and that the solution volume is 30.0 mL.)
A. 2.78 mol/L B. 0.00278 mol/L C. 0.00250 mol/L D. 0.360 mol/L
9. An environmental toxin is present in an extremely small amount in a sample of river water.
What is the best way to report its concentration?
A. mol/L B. % (v/v) C. % (m/m) D. ppm
10. What mass of solute is present in 250. mL of a 0.100 mol/L solution of NaOH (molar mass of
NaOH = 40.00 g/mol)?
A. 0.625 B. 1.00 g C. 6.25 D. 1000 g
 11. A
student dilutes 50.0 mL of a 0.10 mol/L solution of HCl to 0.010 mol/L by adding water.
Which statement is true?
A. The volume of the solution remains the same.
B. The volume of the solvent remains the same.
C. The total amount of solute remains the same.
D. The total amount of solute decreases.
12. When preparing a dilute acid solution from a concentrated acid solution,
A. adding the acid to the water aids the mixing process
B. adding the acid to the water prevents the splattering of hot acid
C. wear appropriate protective clothing and goggles and work in a fume hood
D. all of the above are true
13. How would you prepare 500.0 mL of a 2.00 mol/L solution of HCl from a concentrated solution
of 12.0 mol/L?
A. To some water in a 500.0 mL volumetric flask, add 83.3 mL of concentrated acid, then
dilute to the mark.
B. To some water in a 500.0 mL volumetric flask, add 8.33 mL of concentrated acid, then
dilute to the mark.
C. To some water in a 500.0 mL volumetric flask, add 3.00 mL of concentrated acid, then
dilute to the mark.
D. Pour 83.3 mL of concentrated acid into a 500.0 mL volumetric flask. Dilute with water to
the mark.
14. To prepare 0.250 L of 0.100 M aqueous NaCl (58.4 g/mol), one may
A. dissolve 0.100 g of NaCl in 250 mL of water.
B. dissolve 1.46 g of NaCl in 250 mL of water.
C. dissolve 0.100 g of NaCl in enough water to make 0.250 kg of solution.
D. dissolve 1.46 g of NaCl in enough water to make 0.250 L of solution.
E. dissolve 0.100 g NaCl in 0.250 kg of water.
15. If 25.00 mL of 2.00 M NaCl is transferred by pipet into a volumetric flask and diluted to 5.00 L,
what is the molarity of the diluted NaCl?
A. 0.0100 M B. 0.0160 M C. 0.0625 M D. 0.400 M E. 16.0 M
16. What volume of 6.0 M HNO3 is required to prepare 250 mL of 0.40 M HNO 3?
A. 9.7 mL B. 17 mL C. 27 mL D. 38 mL E. 270 L
17. If 26.5 g of methanol (CH3OH) is added to 735 g of water, what is the molality of the methanol?
A. 0.0348 m B. 2.03 m C. 1.13 m D. 3.61 m E. 36.1 m
18. What mass of Cu(NO3)2 (187.6 g/mol) is present in 25.0 g of 1.00 m Cu(NO3)2(aq)?
A. 3.95 g B. 4.69 g C. 13.8 g D. 25.0 g E. 63.5 g
19The concentration of lead nitrate (Pb(NO 3)2 in a 0.726 M solution is ______
molal. The density of the solution is 1.202 g/ml.
A. 0.476 B. 1.928 C. 0.755 D. 0.819
20. The concentration of a benzene solution prepared by mixing 12.0 g C 6H6 with
38.0 g CCl4 is _____ molal
A. 4.04 B. 240 C. 0.622 D. 031
21. To prepare a solution that is 15.0% aqueous KCl by mass, one should
A. dissolve 15.0 g KCl in 85.0 g H2O.
B. dissolve 15.0 g KCl in 1.00 × 102 g H2O.
C. dissolve 15.0 g KCl in 0.850 mol H2O.
D. dissolve 0.150 mol KCl in 0.850 mol H2O.
 E. dissolve 0.150 mol KCl in 1.00 mol H2O.
22. What mass of HCl is required to prepare 1.00 kg of 5.5% by mass aqueous HCl?
A. 0.018 g B. 5.5 g C. 18 g D. 55 g E. 550 g
23. 1.0 N NaOH is equivalent to 1.0 M NaOH . 12 N Ca(OH) 2 is equivalent to
A. 12 M C. 4 M

Colligative Properties of Solutions

24.Henry's law states that gas solubility is
A. directly proportional to temperature of the solution.
B. directly proportional to the molar mass of the gas.
C. inversely proportional to the combined pressure of all gases over the solution.
D. inversely proportional to the pressure of the gas over the solution.
E. directly proportional to the pressure of the gas over the solution.
25. Which of the following statements concerning osmosis is/are CORRECT?
1. Osmosis involves the movement of a solvent through a semipermeable membrane.
2. Solvents move from regions of high solute concentration to regions of lower solute
concentration.
3. Osmotic pressure is a colligative property.
A. 1 only B. 2 only C. 3 only D. 1 and 3 E. 1, 2, and 3
26. An aqueous solution is composed of 7.50 g NaCl (MM = 58.44 g/mol) diluted to 0.100 L. Calculate
the osmotic pressure of the solution at 298 K. (R = 0.0821 L⋅atm/mol⋅K)
A. 5.83 atm B. 9.22 atm C. 18.3 atm D. 31.4 atm E. 62.8 atm
27. A solution is prepared by dissolving 4.21 g of a nonelectrolyte in 50.0 g of water. If the boiling
point increases by 0.203°C, what is the molar mass of the solute? The boiling point elevation
constant for water is 0.512°C/m.
A. 33.4 g/mol B. 111 g/mol C. 172 g/mol D. 212 g/mol E. 810 g/mol
28. Which of the following electrolytes is likely to have a van't Hoff factor equal to 3?
A. CaI2 B. Na3PO4 C. KCl D. answers a and b E. answers a, b, and c
29. A 0.230 m solution of an unknown electrolyte depresses the freezing point of water by 0.821°C.
What is the Van't Hoff factor for this electrolyte? The freezing point depression constant for water
is 1.86°C/m.
A. 0.521 B. 1.92 C. 2.00 D. 2.30 E. 4.41
30. An isotonic solution will produce an osmotic pressure of 7.84 atm measured against pure
water at human body temperature (37.0 C). How many g of sodium chloride must be
dissolved in a liter of water to produce an isotonic solution?
A. 36.0 g B. 24.0 g C. 18.02 D. 9.01
PH and POH
31. Which of the following household products could have a pH =12.0 ?
A. soda pop B. tap water C. lemon juice D. oven cleaner
32. Which best describes an acid?
A. [H+] > 1.0 x10-7 M at 25 oC C. pH > 7 at 25 o C
B. [H+] = [OH-] D. red litmus turns blue
33.. Which has the largest pH?
A. 0.01 M HCl B. 0.01 M KOH C. 0.1 M HNO3 D. 0.001 M NaOH
34. Which describes tap water that has a pH of 8?
A. acidic with [H +] = 10-8mol/L C. basic with [H +] = 10-8 mol
 B. acidic with [OH -] = 10-8mol/L D. basic with [OH-] = 10-8 mol/L

35.Seawater has a hydroxide ion concentration of 2.0  106 M. What is the pH of seawater?
A. 8.30 B. 5.70 C. 6.99 D. 7.53 E. 8.30
37. All of the following species are strong acids EXCEPT
A. HClO4 B. HBr. C. H2SO4. D. HF E. H
38. All of the following species are strong bases EXCEPT
A. NaOH. B. KOH. C. Mg(OH)2 D. Sr(OH)2. E. RbOH.
39. An aqueous solution with a pH of 2.00 is diluted from 1.0 L to 3.0 L. What is the pH of the diluted
solution?
A. 0.67 B. 2.00 C. 2.48 D. 4.33 E. 6.00
40. Which of the following solutions will have a pH closer to 3.0?
A. 1 x 10-3 M CH3CO2H B. 1x 10-3 M NH3 C. 1 x 10-3 M NH4+ D. 1 x 10-3 M HI
E. Answers b and c are correct.
42. The pH of 10-5 g hydrogen ion per liter of solution is
A. 7 B. 8 C. 5 D. 4 E. 3
43. The pH of a solution is 6.38. Find the concentration of hydroxide ion in moles per liter
A. 2.39 x10-8M B. 2.23 x10 -7 M C. 1.22 x 10 -6 M D. 3.20 x 10-6 M
44. If the solution X has a pH of 6 and solution Y has a hydronium ion concentration twice that of
solution X, the approximate pH of the solution Y is
A. 12.0 B. 3.0 C. 5.7 D. 9.0
-5
44. The acidity constant for acetic acid is 1.8 x 10 . Find pKa
A. 3.6 B. 4.2 C. 4.7 D. 5.4
45. In a 0.1 M cyanic acid is 4.4 percent dissociated. Find Ka
A. 2.0 x 10 -4 B. 2.0 x 10-5 C. 2.0 x 10 -6 D. 2.0 x 10 -7
46. Calculate the pH solution of 0.10 M ammonium hydroxide. Kb = 1.8 x 10 -5
A. 2.9 B. 3.3 C. 11.1 D. 12.2
47. Phenol is a monobasic acid with an ionization constant at 25 oC of 1.3 x 10 -10. What is the pH
value of a I M solution?
A. 1.2 B. 6.44 C.3.45 D. 9.06
48. A solution of acetic acid whose analytical concentration was 0.100 M was found to have a
hydrogen ion concentration of 1.32 x 10 -3 M. Calculate the equilibrium constant for the
dissociation of this acid.
A. 1.76 x 10 -5 B. 2.01 x 10 -4 C. 2.01 x 10 -5 D. 1.76 x 10 -4
49. The pH of a solution is 5.0. Its hydrogen ion concentration is decreased hundred times . Then the
solution will be
A. more acidic B. neutral C. basic D. of the same acidity
50. A 0.20 M solution of a weak acid HA is 0.6% ionized. What is the value of ionization constant,
Ka , for this acid?
A. 7.2 x 10 -6 B. 7.2 x 10 -7 C. 7.9 x 10 -6 D. 7 x10 -5
51.What is the pH of 0.10 M solution of nitrous acid (HNO2)? Ka = 7.2 x 10-4
A. 1.43 B. 4.24 C. 2.07 D. 2.65

Acid – Base Equilibria

52. Which of the following acids build up in muscles that are overexerted, causing pain?
A. Hydrochloric acid B. Acetic acid C. Carbonic acid D. Hypochlorous acid E. Lactic acid
53. An acid-base equilibrium system is created by dissolving 0.50 mol CH3CO2H in water to a
volume of 1.0 L. What is the effect of adding 0.50 mol CH 3CO2–(aq) to this solution?
1. The pH of the solution will equal 7.00 because equal concentrations of a weak acid and its
conjugate base are present.
2. Some CH3CO2H(aq) will ionize, increasing the concentration of CH 3CO2–(aq) and increasing the
pH.
3. Some CH3CO2–(aq) will react with H3O+(aq), increasing the concentration of CH 3CO2H(aq)
and reestablishing the solution equilibrium.
A. 1 only B. 2 only C. 3 only D. 1 and 3 E. 1, 2, and 3
54. What is the effect of adding NaOH(aq) to an aqueous solution of ammonia?
1. The pH of the solution will increase.
2. The concentration of NH4+(aq) will decrease.
3. The concentration of NH3(aq) will increase.
A. 1 only B. 2 only C. 3 only D. 2 and 3 E. 1, 2, and 3
55. All of the following statements concerning acid-base buffers are true EXCEPT
A. buffers are resistant to pH changes upon addition of small quantities of strong acids or bases.
B. buffers are used as colored indicators in acid-base titrations.
C. the pH of a buffer is close to the pKa of the weak acid from which it is made.
D. buffers contain appreciable quantities of a weak acid and its conjugate base.
E. buffers are resistant to changes in pH when diluted with water.
56. Which of the following pairs will form a buffer when mixed together in an aqueous solution?
A. KCl and KH2PO4
B. HCl and KOH
C. Ca(OH)2 and NaOH
D. HF and NaF
E. None of the above will form a buffer.
57. What is the pH of a solution that results from diluting 0.30 mol acetic acid (CH 3CO2H) and 0.20
mol sodium acetate (NaCH3CO2) with water to a volume of 1.0 L? (Ka of CH 3CO2H = 1.8 × 10–5)
A. 4.35 B. 4.57 C. 4.74 D. 4.92 E. 5.14
58. What is the pH of an aqueous solution composed of 0.64 M NH4+ and 0.20 M NH3?
(Ka of NH4+ = 5.6 × 10–10)
A. 4.80 B. 8.75 C. 9.20 D. 9.25 E. 9.76
59. The Ka of hypobromous acid, HOBr, is 2.6 × 10 −9. Calculate the pH of a solution which is
composed of 0.40 M HOBr and 0.40 M NaOBr.
A. 0.40 B. 0.80 C. 4.49 D. 8.59 E. 9.12
60. A buffer may be prepared by mixing a weak acid with a roughly equivalent amount of strong
base. Which of the acids below is best for the preparation of a buffer with a pH of 9.00?
A. chlorous acid, HClO2; Ka = 2.8 × 10 −8
B. formic acid, HCO2H; Ka = 1.9 × 10 −4
C. benzoic acid, HC7H5O2; Ka = 6.6 × 10 −5
D. dihydrogen phosphate ion, H2PO4−; Ka = 6.2 × 10 −8
E. ammonium ion, NH4+; Ka = 5.6 × 10 −10

Solubility and Ksp

61. Consider the equilibrium of PbCl2(s) in water. PbCl2(s) == Pb 2+(aq) + 2Cl−(aq)
What is the effect of adding NaCl(aq) to the equilibrium solution?
A. The sodium ion reduces the Pb 2+ to Pb(s).
B. PbCl2 solubility increases due to the common-ion effect.
C. PbNa2(s) precipitates.
D. The NaCl(aq) has no effect on the system.
 E. PbCl2(s) precipitates until equilibrium is reestablished.
62. Consider the equilibrium of Ca(OH)2(s) in water. Ca(OH) 2(s) === Ca 2+(aq) + 2OH−(aq)
What is the effect of raising the pH of the solution?
A. Ca 2+(aq) is reduced to Ca(s).
B. The concentration of hydronium ion increases.
C. The concentration of Ca 2+ increases as Ca(OH)2 dissolves.
D. Ca(OH)2(s) precipitates until equilibrium is reestablished.
E. Hydroxide ion is reduced to H 2(g).
63. The Ksp of aluminum hydroxide, Al(OH)3, is 2 × 10−31.
What pH is required to limit the Al3+ concentration to less than or equal to 1 × 10−10 M?
A. 3.6 B. 6.4 C. 6.9 D. 7.8 E. 11.5
64. The Ksp of barium chromate is 1.2 × 10−10. What is the concentration of Ba2+ in equilibrium
with BaCrO4(s) if [CrO4 2−] = 4.3 × 10−3 M?
A. 5.1 × 10−13 M B. 2.8 × 10−8 M C. 1.1 × 10−5 M D. 1.7 × 10−4 M E. 2.5 × 10−3 M
65. The Ksp of Fe(OH)3(s) is 3 × 10−39. What concentration of Fe3+ can exist in solution at pH 3.0?
A. 3 × 10−4 M B. 3 × 10−6 M C. 3 × 10−21 M D. 3 × 10−24 M E. 3 × 10−30 M
66. For Ca(OH)2, Ksp = 4.0 × 10−6. What will occur if 1.0 L of 0.100 M Ca(NO 3)2 is prepared in a
solution that is buffered at pH 12.50?
A. Q > Ksp. A precipitate will form.
B. Ksp > Q. A precipitate will form.
C. Q = Ksp. No precipitate will form.
D. Q > Ksp. No precipitate will form.
E. Ksp > Q. No precipitate will form.
67. The Ksp of Ca(OH)2 is 5.5 × 10–5 at 25°C. What is the concentration of OH –(aq) in a saturated
solution of Ca(OH)2(aq)?
A. 1.9 × 10–3 M B. 7.4 × 10–3 M C. 2.4 × 10–2 M D. 4.0 × 10–2 M E. 4.8 × 10–2 M
68. At pH 10.0, only 0.019 g of MgCl2 ( 95.0 g/mol) will dissolve per 1 L of solution. What is the Ksp
of magnesium hydroxide, Mg(OH)2?
A. 2 × 10−13 B. 2 × 10−12 C. 2 × 10−10 D. 2 × 10−8 E. 2 × 10−6
69. What is the water solubility of AgCl (Ksp = 1.8 × 10−10) in 0.25 M NaCl?
A. 4.5 × 10−11 M B. 7.2 × 10−10 M C. 1.8 × 10−9 M D. 1.7 × 10−7 M E. 1.3 × 10−5 M
70. Given the following reactions,
AgBr(s) ===Ag+(aq) + Br–(aq) Ksp = 5.4 × 10–13
Ag+(aq) + 2 CN–(aq) ==== Ag(CN)2–(aq) Kf = 1.2 × 10 21
determine the equilibrium constant for the reaction below.
AgBr(s) + 2 CN–(aq) == Ag(CN)2–(aq) + Br–(aq)
A. 4.5 × 10–34 B. 1.5 × 10–9 C. 6.5 × 108 D. 1.2 × 1021 E. 2.2 × 1033

Lab Concepts
71. A solution containing an unknown metal ion is analyzed by qualitative analysis.
Addition of chloride has no effect on the solution. Addition of H2S at pH 0.5 results in a precipitate.
What group of cations is present?
A. Alkali Group B. Silver Group C. Cu- As Group D . Al- Fe Group E. Alkaline Earth
72 . Which of the following metals will precipitate as chloride salts: Ag+, Pb2+, Ca2+, K+, and Cu2+?
a. Ag+ b. Pb2+, Ca2+, and Cu2+ c. Ag+, K+, and Cu2+ d. Ag+ and Pb2+ e. Ca2+ and Cu2+
73 . In the qualitative analysis scheme, Mg2+ is a group IV cation (alkaline earth group) . What anion
is used to precipitate Mg2+?
a. OH− b. Cl− c. PO4 3− d. S 2− e. CO3 2−
Redox Reactions
74. Which of the following reaction is a redox reaction?
(a) K2CrO4 + BaCl2 →BaCrO4 + 2KCl
(b) Pb2 2+ + 2Br- →PbBr
(c) Cu + S → CuS
A. (a) only B. (b) only C. (c) only D. (a) and (c)
75. Which substance is the reducing agent in the reaction below?
Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O
A. Pb B. H2SO4 C. PbO2 D. PbSO4
76. One of the product formed when nitric acid oxidizes non metal sulfides is,
A. NO B. SO2
C. acid of the non metal D. metal sulfides
77 . One of the product formed when concentrated nitric acid is reacted with metals
A. NO2 B. metallic nitrite C. NO D. metal hydride
78. In which of the following chemical formula is the oxidation number of nitrogen
different?
A. NO3 - B. N2O5 C. NH4Cl D. Ca(NO3)2
79. The oxidation number of zinc in a reaction increases by 2. This indicates that
A. zinc is reduced and loses 2 electrons.
B. zinc is reduced and gains 2 electrons.
C. zinc is oxidized and loses 2 electrons.
D. zinc is oxidized and gains 2 electrons.

80. Consider the redox reaction below:

2 BrO3- + 10Cl- + 10 H+ ----Br2 + 5Cl2 + 6H2O
The oxidation half-reaction involved in this reaction is

A. 2Cl- ---- Cl2 + 2e

B. 2H+ ------ H2 + 2e
C. BrO3- + 6H+ + 5e -------1/2 Br2 + 3H20
D. BrO3- + 6H+ -----1/2 Br2 + 3H2O + 5e