Chemical Engineering Chapter 4 1 Sodium hydroxide, also known as caustic soda, is used to neutralize acids and to treat cellulose in making of cellophane. Calculate the number of moles of solute in

Chapter 4: The Major Classes of Chemical Reactions

1. A 0.150 M sodium chloride solution is referred to as a physiological saline solution

because it has the same concentration of salts as normal human blood. Calculate the mass of

solute needed to prepare 275.0 mL of a physiological saline solution.

A) 41.3 g B) 31.9 g C) 16.1 g D) 8.77 g E) 2.41 g

2. Sodium chlorate is used as an oxidizer in the manufacture of dyes, explosives, and

matches. Calculate the mass of solute needed to prepare 1.575 L of 0.00250 M NaClO3 ( =

106.45 g/mol).

A) 419 g B) 169 g C) 0.419 g D) 0.169 g E) 0.00394 g

3. Lithium hydroxide is used in alkaline batteries. Calculate the molarity of a solution

prepared by dissolving 1.495 moles of LiOH in enough water to give a final volume of 750. mL.

A) 1.99 M B) 1.50 M C) 1.12 M D) 0.502 M E) 0.00199 M

4. Hydrochloric acid is widely used as a laboratory reagent in refining ore for the

production of tin and tantalum, and as a catalyst in organic reactions. Calculate the number of

moles of HCl in 62.85 mL of 0.453 M hydrochloric acid.

A) 28.5 mol

B) 1.04 mol

C) 0.139 mol

D) 0.0285 mol

E) 0.00721 mol

5. Sodium hydroxide, also known as caustic soda, is used to neutralize acids and to treat

cellulose in making of cellophane. Calculate the number of moles of solute in 1.875 L of 1.356

M NaOH solution.

A) 2.543 mol D) 0.3932 mol

B) 1.383 mol E) 0.001383 mol

C) 0.7232 mol

6. Calculate the molarity of a 23.55-mL solution which contains 28.24 mg of sodium

sulfate (used in dyeing and printing textiles, = 139.04 g/mol).

A) 8.625 M B) 1.199 M C) 0.8339 M D) 0.2031 M E) 0.008625 M

Chapter 4: The Major Classes of Chemical Reactions

7. When 2.61 g of solid Na2CO3 is dissolved in sufficient water to make 250. mL of

solution, the concentration of Na2CO3 is:

A) 0.0246 M B) 10.4 M C) 0.205 M D) 0.0985 M E) 0.141 M

8. Calcium chloride is used to melt ice and snow on roads and sidewalks and to remove

water from organic liquids. Calculate the molarity of a solution prepared by diluting 165 mL of

0.688 M calcium chloride to 925.0 mL.

A) 3.86 M B) 0.743 M C) 0.222 M D) 0.123 M E) 0.114 M

9. What will be the final volume of a solution prepared by diluting 25 mL of 8.25 M

sodium hydroxide to a concentration of 2.40 M?

A) 330 mL B) 210 mL C) 86 mL D) 60 mL E) 7.3 mL

10. What volume, in L, of 10.0 M HCl is needed to make 2.00 L of 2.00 M HCl solution by

dilution with water?

A) 0.800 L B) 0.400 L C) 0.200 L D) 0.100 L E) none of the above

11. How many mL of concentrated nitric acid (HNO3, 16.0 M) should be diluted with water

in order to make 2.00 L of 2.00 M solution?

A) 32.0 mL B) 62.5 mL C) 125 mL D) 250. mL E) 500. mL

12. Potassium chloride, KCl, sodium sulfate, Na2SO4, glucose, C6H12O6, carbon dioxide,

CO2 and ammonium phosphate, (NH4)3PO4, are soluble in water. Which one produces the

largest number of dissolved particles per mole of dissolved solute?

A) KCl B) Na2SO4 C) C6H12O6 D) CO2 E) (NH4)3PO4

13. Potassium carbonate, K2CO3, sodium iodide, NaI, magnesium chloride, MgCl2,

methanol, CH3OH, and ammonium chloride, NH4Cl, are soluble in water. Which produces the

largest number of dissolved particles per mole of dissolved solute?

A) K2CO3 B) NaI C) MgCl2 D) CH3OH E) NH4Cl

14. How many moles of ions are released when 0.27 mol of cobalt(II) chloride, CoCl2, is

dissolved in water?

A) 0.81 mol B) 0.54 mol C) 0.27 mol D) 0.18 mol E) 0.090 mol

Chapter 4: The Major Classes of Chemical Reactions

15. How many moles of ions are released when 1.6 mol of ammonium phosphate,

(NH4)3PO4, is dissolved in water?

A) 0.40 mol B) 1.6 mol C) 3.2 mol D) 4.8 mol E) 6.4 mol

16. How many moles of H+(aq) ions are present in 750 mL of 0.65 M hydrochloric acid?

A) 1.2 mol B) 0.98 mol C) 0.87 mol D) 0.65 mol E) 0.49 mol

17. How many moles of H+(aq) ions are present in 1.25 L of 0.75 M nitric acid?

A) 0.60 mol B) 0.75 mol C) 0.94 mol D) 1.7 mol E) 1.9 mol

18. How many sodium ions are present in 325 mL of 0.850 M Na2SO4?

A) 1.66 × 1023 sodium ions D) 6.20 × 1023 sodium ions

B) 3.33 × 1023 sodium ions E) 1.57 × 1024 sodium ions

C) 4.99 × 1023 sodium ions

19. Which of the following is most soluble in water?

A) benzene, C6H6 D) hexane, C6H14

B) potassium nitrate, KNO3 E) ethane, C2H4

C) carbon tetrachloride, CCl4

20. Which of the following will be least soluble in water?

A) potassium sulfate, K2SO4 D) calcium chloride, CaCl2

B) ammonium nitrate, NH4NO3 E) ethanol, C2H6O

C) chloromethane, CH3Cl

21. Which one of the following ionic compounds is insoluble in water?

A) Na3PO4 B) AgNO3 C) NaCl D) CaCO3 E) MgCl2

22. Which one of the following ionic compounds is soluble in water?

A) Na2S B) PbI2 C) AgCl D) CuS E) Ca3(PO4)2

23. Which of the following solutions will be the poorest conductor of electrical current?

A) sucrose, C12H22O11(aq) D) lithium hydroxide, LiOH(aq)

B) sodium chloride, NaCl(aq) E) sulfuric acid, H2SO4(aq)

C) potassium nitrate, KNO3(aq)

Chapter 4: The Major Classes of Chemical Reactions

24. Which of the following solutions will be the best conductor of electrical current?

A) methyl alcohol, CH3OH(aq) D) bromine, Br2(aq)

B) glucose, C6H12O6(aq) E) ethylene glycol, C2H6O2(aq)

C) potassium chloride, KCl(aq)

25. 1.0 M aqueous solutions of the following substances are prepared. Which one would you

expect to have the lowest electrical conductivity?

A) NaOH D) CH3COOH (acetic acid)

B) CH3CH2OH (ethanol) E) HClO4

C) KBr

26. Which one of the following substances, when dissolved in water at equal molar

concentrations, will give the solution with the lowest electrical conductivity?

A) CaCl2 B) HNO3 C) NH3 D) C6H12O6 (glucose) E) CO2

27. Which one of the following substances is the best electrolyte?

A) CO B) CH3Cl C) CH4 D) C2H5OH E) HCl

28. In the following reaction, what ions, if any, are spectator ions?

Pb(NO3)2(aq) + 2NaCl(aq) → PbCl2(s) + 2NaNO3(aq)

A) Pb2+(aq), Cl–(aq) D) Na+(aq), Cl–(aq)

B) Na+(aq), NO3–(aq) E) There are no spectator ions.

C) Pb2+(aq), NO3–(aq)

29. What, if any, are the spectator ions when aqueous solutions of HBr and RbOH neutralize

each other?

A) H+ and OH–

B) H+ and Rb+

C) Rb+ and Br–

D) Br– and OH–

E) There are no spectator ions in this reaction.

Chapter 4: The Major Classes of Chemical Reactions

30. Magnesium carbonate, MgCO3, is insoluble. Identify the spectator ions when aqueous

solutions of sodium carbonate and magnesium chloride are combined.

A) Mg2+ and CO32-

B) Na+ and Cl–

C) Mg2+ and Cl–

D) Na+ and CO32-

E) None of the above correctly identifies the spectator ions.

31. Select the precipitate that forms when the following reactants are mixed.

Na2CO3(aq) + BaCl2(aq) →

A) Ba2CO3 B) BaCO3 C) NaCl D) NaCl2 E) BaO

32. Select the precipitate that forms when the following reactants are mixed.

Mg(CH3COO)2(aq) + LiOH(aq) →

A) LiCH3COO

B) Li(CH3COO)2

C) MgOH

D) Mg(OH)2

E) CH3OH

33. Select the precipitate that forms when aqueous ammonium sulfide reacts with aqueous

copper(II) nitrate.

A) CuS B) Cu2S C) NH4NO3 D) NH4(NO3)2 E) CuSO4

34. Select the precipitate that forms when aqueous lead(II) nitrate reacts with aqueous

sodium sulfate.

A) NaNO3 B) Na2NO3 C) PbSO4 D) Pb2SO4 E) PbS

35. Select the correct name and chemical formula for the precipitate that forms when the

following reactants are mixed.

CuCl2(aq) + Na2CO3(aq) →

A) copper(I) carbonate, Cu2CO3 D) copper(II) carbonate, CuCO3

B) copper(II) carbonate, Cu2CO3 E) sodium chloride, NaCl

C) copper(I) carbonate, CuCO3

Chapter 4: The Major Classes of Chemical Reactions

36. Select the correct name and chemical formula for the precipitate that forms when the

following reactants are mixed.

CoSO4(aq) + (NH4)3PO4(aq) →

A) cobalt(II) phosphate, Co3(PO4)2 D) cobalt(III) phosphate, CoPO4

B) cobalt(III) phosphate, Co3(PO4)2 E) ammonium sulfate, (NH4)2SO4

C) cobalt(II) phosphate, CoPO4

37. Select the net ionic equation for the reaction between sodium chloride and mercury(I)

nitrate.

2NaCl(aq) + Hg2(NO3)2(aq) → NaNO3(aq) + Hg2Cl2(s)

A) Na+(aq) + NO3–(aq) → NaNO3(aq)

B) Hg22+(aq) + 2Cl–(aq) → Hg2Cl2(s)

C) NaCl(aq) → Na+(aq) + Cl–(aq)

D) Hg2(NO3)2(aq) → Hg22+(aq) + 2NO3–(aq)

E) Hg22+(aq) → Hg2(s)

38. Consider the reaction:

3Co2+(aq) + 6NO3–(aq) + 6Na+(aq) + 2PO43-(aq) → Co3(PO4)2(s) + 6Na+(aq) + 6NO3–(aq)

Identify the net ionic equation for this reaction.

A) Na+(aq) + NO3–(aq) → NaNO3(aq)

B) 3Co2+(aq) + NO3–(aq) + Na+(aq) + 2PO43-(aq) → Co3(PO4)2(s) + NaNO3(aq)

C) 3Co2+(aq) + 6NO3–(aq) + 6Na+(aq) + 2PO43-(aq) → Co3(PO4)2(s) + 6NaNO3(aq)

D) 3Co2+(aq) + 2PO43-(aq) → Co3(PO4)2(s)

E) None of the above is the correct net ionic equation.

39. Copper(II) sulfide, CuS, is used in the development of aniline black dye in textile

printing. What is the maximum mass of CuS which can be formed when 38.0 mL of 0.500 M

CuCl2 are mixed with 42.0 mL of 0.600 M (NH4)2S? Aqueous ammonium chloride is the other

product.

A) 2.41 g B) 1.82 g C) 1.21 g D) 0.909 g E) 0.044 g

40. An acid

A) produces hydroxide ions when dissolved in water.

B) changes the color of phenolphthalein indicator from colorless to pink.

C) donates electrons in an electron transfer reaction.

D) donates protons in a proton transfer reaction.

E) does none of the above.

Chapter 4: The Major Classes of Chemical Reactions

41. A base

A) causes phenolphthalein indicator to change from colorless to pink.

B) donates a proton in a proton transfer reaction.

C) accepts electrons in an electron transfer reaction.

D) produces hydrogen ions in solution.

E) does none of the above.

42. Which of the following is a weak acid?

A) H2SO4 B) HNO3 C) HF D) HBr E) HCl

43. Which, if any, of the following properties applies to weak acids?

A) They are strong electrolytes.

B) They are excellent conductors of electricity.

C) When dissolved in water, they do not ionize completely.

D) all of the above

E) none of the above

44. Which of the following is a strong acid?

A) H3PO4 B) HNO3 C) HF D) CH3COOH E) H2O

45. Which of the following is a strong base?

A) NH3 B) Ca(OH)2 C) Al(OH)3 D) B(OH)3 E) CH3OH

46. Which of the following is a weak base?

A) NH3 B) Ca(OH)2 C) Ba(OH)2 D) NaOH E) CH3COOH

47. Ammonia, NH3, produces hydroxide ions in aqueous solution by

A) donating a proton to an acid molecule.

B) donating a proton to a water molecule.

C) donating a hydrogen ion to a water molecule.

D) accepting an electron from an acid molecule.

E) accepting a proton from a water molecule.

48. Which one of the following substances is a strong acid?

A) HNO3 B) H2CO3 C) NH3 D) CH3COOH E) H3PO4

Chapter 4: The Major Classes of Chemical Reactions

49. Select the correct set of products for the following reaction.

Ba(OH)2(aq) + HNO3(aq) →

A) BaN2(s) + H2O(l) D) Ba2O(s) + NO2(g) + H2O(l)

B) Ba(NO3)2(aq) + H2O(l) E) No reaction occurs.

C) Ba(s) + H2(g) + NO2(g)

50. Select the net ionic equation for the reaction between lithium hydroxide and hydrobromic

acid.

LiOH(aq) + HBr(aq) → H2O(l) + LiBr(aq)

A) LiOH(aq) → Li+(aq) + OH–(aq)

B) HBr(aq) → H+(aq) + Br–(aq)

C) H+(aq) + OH–(aq) → H2O(l)

D) Li+(aq) + Br–(aq) → LiBr(aq)

E) Li+(aq) + OH–(aq) + H+(aq) + Br–(aq) → H2O(l) + LiBr(aq)

51. A standard solution of 0.243 M NaOH was used to determine the concentration of a

hydrochloric acid solution. If 46.33 mL of NaOH is needed to neutralize 10.00 mL of the acid,

what is the molar concentration of the acid?

A) 0.0524 M B) 0.888 M C) 1.13 M D) 2.26 M E) 2.43 M

52. Automobile batteries use 3.0 M H2SO4 as an electrolyte. How much 1.20 M NaOH will

be needed to neutralize 225 mL of battery acid?

H2SO4(aq) + 2NaOH(aq) → 2H2O(l) + Na2SO4(aq)

A) 0.045 L B) 0.28 L C) 0.56 L D) 0.90 L E) 1.1 L

53. Vinegar is a solution of acetic acid, CH3COOH, dissolved in water. A 5.54-g sample of

vinegar was neutralized by 30.10 mL of 0.100 M NaOH. What is the percent by weight of acetic

acid in the vinegar?

A) 0.184% B) 1.63% C) 3.26% D) 5.43% E) 9.23%

54. A 0.00100 mol sample of Ca(OH)2 requires 25.00 mL of aqueous HCl for neutralization

according to the reaction below. What is the concentration of the HCl?

Equation: Ca(OH)2(s) + 2HCl(aq) → CaCl2(aq) + H2O(l)

A) 0.0200 M D) 4.00 × 10–5 M

B) 0.0400 M E) none of the above

C) 0.0800 M

Chapter 4: The Major Classes of Chemical Reactions

55. How many milliliters of 1.58 M HCl are needed to react completely with 23.2 g of

NaHCO3 ( = 84.02 g/mol)?

HCl(aq) + NaHCO3(s) → NaCl(s) + H2O(l) + CO2(g)

A) 638 mL B) 572 mL C) 536 mL D) 276 mL E) 175 mL

56. Select the best statement relating to the following reaction:

2MnO2(s) + KClO3(aq) + 2KOH(aq) → 2KMnO4(aq) + KCl(aq) + H2O(l)

A) Mn in MnO2 is oxidized. D) H in KOH is oxidized.

B) O in KClO3 is the oxidizing agent. E) Cl in KClO3 is the reducing agent.

C) K in KClO3 is the reducing agent.

57. In a redox reaction, electrons are transferred

A) from the substance being oxidized to the reducing agent.

B) from the oxidizing agent to the reducing agent.

C) from the substance being reduced to the oxidizing agent.

D) from the substance being oxidized to the substance being reduced.

E) from the substance being reduced to the substance being oxidized.

58. Calculate the oxidation number of the chlorine in perchloric acid, HClO4, a strong

oxidizing agent.

A) –1

B) +4

C) +5

D) +7

E) None of the above is the correct oxidation number.

59. Calculate the oxidation number of sulfur in sodium metabisulfite, Na2S2O5.

A) –2

B) +2

C) +4

D) +5

E) None of the above is the correct oxidation number.

Chapter 4: The Major Classes of Chemical Reactions

60. Sodium tripolyphosphate is used in detergents to make them effective in hard water.

Calculate the oxidation number of phosphorus in Na5P3O10.

A) +3

B) +5

C) +10

D) +15

E) None of the above is the correct oxidation number.

61. What is the oxidation number of iodine in I2.

A) –1

B) 0

C) +1

D) +7

E) None of the above is the correct oxidation number.

62. The oxidation numbers of P, S, and Cl in H2PO2–, H2S, and KClO4 are, respectively

A) –1, –1, +3. D) –1, –2, +7.

B) +1, –2, +7. E) –1, –2, +3.

C) +1, +2, +7.

63. Which of the statements below correctly describes the combustion of glucose, shown

below?

C6H12O6 + 6O2 → 6CO2 + 6H2O

A) Hydrogen in C6H12O6 is being reduced.

B) Oxygen in O2 is being oxidized.

C) Hydrogen in C6H12O6 is the reducing agent.

D) Oxygen in C6H12O6 is the oxidizing agent.

E) Carbon in C6H12O6 is being oxidized.

64. Identify the oxidizing agent in the following redox reaction.

Hg2+(aq) + Cu(s) → Cu2+(aq) + Hg(l)

A) Hg2+(aq)

B) Cu(s)

C) Cu2+(aq)

D) Hg(l)

E) Hg2+(aq) and Cu2+(aq)

Chapter 4: The Major Classes of Chemical Reactions

65. Sodium thiosulfate, Na2S2O3, is used as a “fixer” in black and white photography.

Identify the reducing agent in the reaction of thiosulfate with iodine.

2S2O32–(aq) + I2(aq) → S4O62–(aq) + 2I–(aq)

A) I2(aq) D) S4O62–(aq)

B) I–(aq) E) S2O32–(aq) and I–(aq)

C) S2O32–(aq)

66. Which one of the following is not a redox reaction?

A) 2H2(g) + O2(g) → 2H2O(l)

B) Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g)

C) H2O(l) + NH3(g) → NH4+(aq) + OH–(aq)

D) 6FeSO4(aq) + K2Cr2O7(aq) + 7H2SO4(aq) → Cr2(SO4)3(aq) + 3Fe2(SO4)3(aq) +

K2SO4(aq) + 7H2O(l)

E) Cl2(g) + 2KBr(aq) → Br2(l) + 2KCl(aq)

67. Which one of the following is not a redox reaction?

A) 2H2O2(aq) → 2H2O(l) + O2(g)

B) N2(g) + 3H2(g) → 2NH3(g)

C) BaCl2(aq) + K2CrO4(aq) → BaCrO4(aq) + 2KCl(aq)

D) 2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(s)

E) 2H2O(g) → 2H2(g) + O2(g)

68. Which one of the following is a redox reaction?

A) 2Na(g) + Cl2(g) → 2NaCl(s)

B) Ba2+(aq) + SO42–(aq) → BaSO4(s)

C) K2Cr2O7(aq) + 2KOH(aq) → 2K2CrO4(aq) + H2O(l)

D) Na2CO3(s) + 2HCl(aq) → 2NaCl(aq) + CO2(g) + H2O(l)

E) H2O(l) → H+(aq) + OH–(aq)

69. Which one of the following is not a redox reaction?

A) 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

B) H2(g) + Cl2(g) → 2HCl(g)

C) 2H2O2(aq) → 2H2O(l) + O2(g)

D) Fe2O3(s) + 3H2SO4(aq) → Fe2(SO4)3(aq) + 3H2O(l)

E) 2KMnO4(aq) + 10FeSO4(aq) + 8H2SO4(aq) → K2SO4(aq) + 2MnSO4(aq) +

5Fe2(SO4)3(aq) + 8H2O(l)

Chapter 4: The Major Classes of Chemical Reactions

70. Identify all the spectator ions in the following reaction.

2KMnO4(aq) + 10FeSO4(aq) + 8H2SO4(aq) → K2SO4(aq) + 2MnSO4(aq) + 5Fe2(SO4)3(aq) +

8H2O(l)

A) only K+ D) only K+, SO42–, and Fe2+

B) only SO42– E) only K+, SO42–, Fe2+, and Mn2+

C) only K+ and SO42–

71. The amount of calcium present in milk can be determined by adding oxalate to a sample

and measuring the mass of calcium oxalate precipitated. What is the mass percent of calcium if

0.429 g of calcium oxalate forms in a 125-g sample of milk when excess aqueous sodium oxalate

is added?

Na2C2O4(aq) + Ca2+(aq) → CaC2O4(s) + 2Na+(aq)

A) 0.107% B) 0.202% C) 0.343% D) 1.10% E) 1.37%

72. Aqueous potassium iodate (KIO3) and potassium iodide (KI) react in the presence of

dilute hydrochloric acid, as shown below.

KIO3(aq) + 5KI(aq) + 6HCl(aq) → 3I2(aq) + 6KCl(aq) + 3H2O(l)

What mass of iodine (I2) is formed when 50.0 mL of 0.020 M KIO3 solution reacts with an

excess of KI and HCl?

A) 0.13 g I2

B) 0.25 g I2

C) 0.38 g I2

D) 0.76 g I2

E) none of the above

73. Aqueous potassium iodate (KIO3) and potassium iodide (KI) react in the presence of

dilute hydrochloric acid (HCl), as shown below.

KIO3(aq) + 5KI(aq) + 6HCl(aq) → 3I2(aq) + 6KCl(aq) + 3H2O(l)

What mass of iodine (I2) is formed when 15.0 mL of 0.0050 M KIO3 solution reacts with 30.0

mL of 0.010 M KI solution in the presence of excess HCl?

A) 0.023 g I2 B) 0.029 g I2 C) 0.057 g I2 D) 0.046 g I2 E) 0.076 g I2

74. Select the classification for the following reaction.

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

A) precipitation D) combination

B) acid-base E) none of the above

C) redox

Chapter 4: The Major Classes of Chemical Reactions

75. Select the classification for the following reaction.

Fe2+(aq) + 2OH–(aq) → Fe(OH)2(s)

A) precipitation D) decomposition

B) acid-base E) none of the above

C) redox

76. Select the classification for the following reaction.

NH3(aq) + HNO3(aq) → NH4NO3(aq)

A) precipitation D) decomposition

B) acid-base E) none of the above

C) redox

77. Select the classification for the following reaction.

KOH(aq) + HCl(aq) → KCl(aq) + H2O(l)

A) precipitation D) combination

B) acid-base E) none of the above

C) redox

78. Select the classification for the following reaction.

Fe(s) + 2Fe3+(aq) → 3Fe2+(aq)

A) precipitation D) decomposition

B) acid-base E) none of the above

C) redox

79. Select the classification for the following reaction.

BaCl2(aq) + K2SO4(aq) → BaSO4(s) + 2KCl(aq)

A) precipitation D) decomposition

B) acid-base E) none of the above

C) redox

80. Select the classification for the following reaction.

H2(g) + Cl2(g) → 2HCl(g)

A) combination D) acid-base

B) decomposition E) none of the above

C) displacement

Chapter 4: The Major Classes of Chemical Reactions

81. The compound P4O10 is used in refining sugar. Select the classification for the reaction in

which it is synthesized.

P4(s) + 5O2(g) → P4O10(s)

A) combination D) acid-base

B) decomposition E) precipitation

C) displacement

82. Select the classification for the following reaction.

Na2O(s) + H2O(l) → 2NaOH(aq)

A) combination D) acid-base

B) decomposition E) precipitation

C) displacement

83. Select the classification for the following reaction.

2NaCl(l)

electricity

2Na(l) + Cl2(g)

A) acid-base D) displacement

B) precipitation E) decomposition

C) combination

84. Select the classification for the following reaction.

2H2O2(aq) → 2H2O(l) + O2(g)

A) combination D) acid-base

B) decomposition E) none of the above

C) displacement

85. Select the classification for the following reaction.

CaCl2H2O(s)

heat

CaCl2(s) + H2O(g)

A) combination D) acid-base

B) decomposition E) precipitation

C) displacement

86. Select the classification for the following reaction.

H2CO3(aq) → H2O(l) + CO2(g)

A) combination D) acid-base

B) decomposition E) none of the above

C) displacement

Chapter 4: The Major Classes of Chemical Reactions

87. Select the classification for the following reaction.

2Ag+(aq) + Zn(s) → 2Ag(s) + Zn2+(aq)

A) displacement D) precipitation

B) decomposition E) acid-base

C) combination

88. Select the classification for the following reaction.

2I–(aq) + Cl2(aq) → I2(aq) + 2Cl –(aq)

A) combination D) precipitation

B) displacement E) acid-base

C) decomposition

89. Predict the product(s) for the following reaction.

Cl2O7(g) + H2O(l) →

A) HClO4(aq) D) HCl(aq) + O2(g)

B) H2ClO4(aq) E) HClO3(aq)

C) H(ClO4)2 (aq)

90. Predict the product(s) for the following reaction.

BaO(s) + CO2(g) →

A) Ba(s) + CO3(g) D) Ba(s) + CO32–(s)

B) BaCO3(s) E) No reaction occurs.

C) BaO(s) + C(s)

91. Predict the product(s) for the following reaction.

H2SO4(aq) + KOH(aq) →

A) K2SO4(aq) + H2O(l) D) KSO4(aq) + H2O(l)

B) K2S(aq) + H2O(l) E) No reaction occurs.

C) K(s) + H2(g) + SO3(g)

92. Predict the product(s) for the following reaction.

MgCO3(s)

heat

A) MgO2(s) + CO(g) D) Mg2+(s) + CO2(g) + O2(g)

B) MgO(s) + CO2 E) No reaction occurs.

C) Mg(s) + CO2(g) + O2(g)

Chapter 4: The Major Classes of Chemical Reactions

93. Predict the products by completing a balanced equation for the following decomposition

reaction.

CaCl2(l)

electricity

?

A) CaCl2(l)

electricity

Ca(l) + 2Cl–(l)

B) CaCl2(l)

electricity

Ca2+(l) + Cl2(g)

C) CaCl2(l)

electricity

Ca2+(l) + 2Cl–(l)

D) CaCl2(l)

electricity

Ca(l) + Cl2(g)

E) CaCl2(l)

electricity

CaCl(l) + Cl–(l)

94. An aqueous solution of lead nitrate, Pb(NO3)2, is mixed with one of sodium chromate,

Na2CrO4, resulting in the formation of a precipitate of lead chromate. Write a balanced net ionic

equation for this precipitation reaction, showing all phases.

95. In both of the following reactions, a precipitate is formed. Complete and balance the

equations, showing the phases of the products.

a. AgNO3(aq) + CaCl2(aq) →

b. NaOH(aq) + Fe(NO3)3(aq) →

96. In both of the following reactions, a precipitate is formed. Complete and balance the

equations, showing the phases of the products.

a. BaCl2(aq) + Na2SO4(aq) →

b. Mg(NO3)2(aq) + KOH(aq) →

97. Complete and balance the equation for the following acid-base reaction.

Ca(OH)2(aq) + HCl(aq) →

Chapter 4: The Major Classes of Chemical Reactions

98. a. You are provided with a 250 mL volumetric flask, deionized water, and solid NaOH.

How much NaOH should be weighed out in order to make 250. mL of 0.100 M solution?

b. 25.0 mL of the 0.100 M aqueous NaOH is titrated against sulfuric acid, H2SO4, according to

the equation

2NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + 2H2O(l)

If the volume of sulfuric acid solution required to neutralize the NaOH is 18.62 mL, what is its

concentration?

99. Sulfuric acid (H2SO4) reacts with potassium hydroxide (KOH) as follows.

H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(l)

Calculate the volume of 0.100 M sulfuric acid required to neutralize 25.0 mL of 0.0821 M KOH.

Show all your work.

100. A 0.1873 g sample of a pure, solid acid, H2X was dissolved in water and titrated with

0.1052 M NaOH solution. The balanced equation for the neutralization reaction occurring is

H2X(aq) + 2NaOH(aq) → Na2X(aq) + 2H2O(l)

If the molar mass of H2X is 85.00 g/mol, calculate the volume of NaOH solution needed in the

titration.

101. In each of the following cases, write down the oxidation number of the indicated atom.

a. P in P4

b. C in C2H6

c. S in H2SO4

d. Mn in MnO4–

e. S in S4O62–

f. P in Na3PO4

Chapter 4: The Major Classes of Chemical Reactions

102. Write down the oxidation number of the indicated atom in each of the following

formulas:

a. Si in SiO2

b. Cl in ClO2–

c. Mn in KMnO4

d. C in C6H12O6

103. For each of the following species, write down, next to the formula, the oxidation number

of the indicated atom.

a. P in H2PO2–

b. S in Na2S2O3

c. C in CH2O

104. a. Explain or define what is meant by the term “oxidation.”

b. Write down the oxidation numbers of all the atoms in the following formulas.

K2Cr2O7 NaH

105. a. Define “oxidation”.

b. Identify the oxidizing and reducing agents in the following (unbalanced) equation.

HNO3(aq) + C2H6O(aq) + K2Cr2O7(aq) → KNO3(aq) + C2H4O(aq) + H2O(l) + Cr(NO3)3(aq)

106. You are provided with a 250 mL volumetric flask, deionized water, and solid NaOH.

How much NaOH should be weighed out in order to make 250. mL of 0.100 M solution?

107. A solution of methanol (CH4O) in water has a concentration of 0.200 M. What mass of

methanol, in grams, is present in 0.150 liters of this solution?

Chapter 4: The Major Classes of Chemical Reactions

108. a. A solution of common salt, NaCl, in water has a concentration of 0.0921 M. Calculate

the number of moles of NaCl contained in 50.0 mL of this solution.

b. If, instead, an NaCl solution is prepared by dissolving 10.0 g of solid NaCl in enough water to

make 250. mL of solution, what is the molarity?

109. Aluminum metal dissolved in hydrochloric acid as follows:

2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g)

a. What is the minimum volume of 6.0 M HCl(aq) needed to completely dissolve 3.20 g of

aluminum in this reaction?

b. What mass of AlCl3 would be produced by complete reaction of 3.20 g of aluminum?

110. The correct method for preparing one liter of a 1.0 M solution of X is to dissolve exactly

one mole of X in exactly one liter of water.

111. When a solution is diluted with water, the ratio of the initial to final volumes of solution

is equal to the ratio of final to initial molarities.

112. Some covalent compounds dissolve in water to produce conducting solutions.

113. Covalent compounds, dissolved in water, never produce conducting solutions.

114. In an acid-base (neutralization) reaction the indicator will change color at the end point.

115. In an acid-base (neutralization) reaction the equivalence point is the point where the

indicator changes color.

116. All acid-base reactions produce a salt and water as the only products.

117. A particular reaction may be both a precipitation and an acid-base (neutralization)

reaction.

Chapter 4: The Major Classes of Chemical Reactions

118. Oxidation is associated with an increase in oxidation number.

119. Reduction is the loss of electrons.

120. In a redox reaction, the reducing agent undergoes loss of electrons.

121. In a redox reaction, the oxidizing agent undergoes loss of electrons.

122. All combustion reactions are classified as combination reactions.

123. The combustion of an element is always a combination reaction.

124. A combination reaction may also be a displacement reaction.

125. Chemical reactions generally reach equilibrium because one of the reactants is used up.