1. Using the periodic table, predict what the proper empirical formula will be when magnesium reacts with fluorine to form an ionic solid.
   1. MgF₂
   2. MgF
   3. Mg₂F
   4. Mg₂F₂
   5. it cannot be determined.

2. How many grams does 4.00 moles of H₂O weigh?
   1. 4.00 g
   2. 4.50 g
   3. 18.0 g
   4. 72.0 g
   5. 144.0 g

3. How many H₂O molecules are there in a snow flake that weighs 4.0 x 10^-4 g?
   1. 1.3 x 10¹⁹
   2. 2.4 x 10²⁰
   3. 2.2 x 10^-5
   4. 6.02 x 10²³
   5. it cannot be determined

4. If you take a 0.100 g dose of Vitamin C, C₆H₈O₆, how many moles is this?
   1. 0.100 mol
   2. 5.68 x 10^-4 mol
   3. 17.61 mol
   4. 2.01 mol
   5. 6.84 x 10^-2 mol

5. For the following reaction, what is the stoichiometric coefficient for water that balances the reaction?
   N₂O₅ + ___ H₂O --> ___ HNO₃
   1. 1
   2. 2
   3. 3
   4. 4
   5. 5

6. For the following combustion reaction, what is the stoichiometric coefficient for oxygen that balances the reaction?
   C₃H₈ + __ O₂ --> ___ H₂O + ___ CO₂
   1. 1
   2. 2
   3. 3
   4. 4
   5. 5

7. The following reaction: 2Mg + O₂ --> 2MgO can be classified as a
   1. Combustion reaction
   2. Acid-base reaction
   3. Decomposition reaction
   4. Combination reaction
   5. None of these

8. What is the percent composition of phosphorous in P₄O₁₀?
   1. 10.9%
   2. 60.0%
   3. 43.6%
   4. 36.4%
   5. 100%

9. Consider the following (balanced) combustion reaction. If 16 g of CH₄ are consumed, what is the amount of H₂O produced, in g?
   CH₄ + 2O₂ --> CO₂ + 2H₂O

   MW CH4 = 16 g/mol	MW O2 = 32 g/mol
   MW CO2 = 44 g/mol	MW H2O = 18 g/mol

   1. 64 g
   2. 32 g
   3. 18 g
   4. 36 g
   5. 44 g

10. What is the average mass of 10 aluminum atoms?
    1. 26.981 amu
    2. 1.624 x 10^-26 g
    3. 269.81 g
    4. 4.481 x 10^-22 g
    5. 1.661 x 10^-24 g

11. The common name for acetic acid is vinegar. The chemical formula is CH₃CO₂H. How many atoms of hydrogen are present in 35.00 moles of vinegar?
    1. 8.431 x 10²⁵
    2. 2.108 x 10²⁵
    3. 1.400 x 10²
    4. 1.744 x 10^-22
    5. 2.401 x 10²⁴

12. In the balanced equation for the reaction:
    NH₃(g) + O₂(g) --> NO(g) + H₂O(g)

    The coefficient for O₂ is:

    1. 1
    2. 3
    3. 5
    4. 8
    5. 10

13. What is the empirical formula of a compound that contains 30.43% N and 69.57% O?
    1. N₂O
    2. NO
    3. NO₂
    4. N₂O₃
    5. N₂O₄

14. Solid lithium hydroxide is used by NASA to remove (scrub) carbon dioxide from the spacecraft by reacting with the carbon dioxide to form solid lithium carbonate and liquid water. The balanced equation is:
    2LiOH(s) + CO₂(g) --> Li₂CO₃(s) + H₂O(l)

    What mass of lithium carbonate will be formed by reacting 3.80 kg of lithium hydroxide with excess carbon dioxide?

    1. 3.80 kg
    2. 5.86 kg
    3. 11.7 kg
    4. 280 kg
    5. not enough information

15. Apatite is a mineral found in tooth enamel. When fluoride toothpastes are used, the mineral is converted to fluoroapatite, which is much harder and therfore more resistant to tooth decay. The formula for fluoroapatite is Ca₅(PO₄)₃F. What is the molecular weight?
    1. 106.1 g/mol
    2. 200.4 g/mol
    3. 314.4. g/mol
    4. 424.3 g/mol
    5. 504.3 g/mol

16. Which is the limiting reagent when 10.0 g of H₂ and 10.0 g of Cl₂ react according to the reaction:
    H₂(g) + Cl₂(g) --> 2HCl(g)
    1. H₂
    2. Cl₂
    3. HCl
    4. Not enough information.
    5. None of the above. They are present in equal amounts.

17. How many chlorine atoms are contained in 18.29 g of chlorine given that the atomic weight of chlorine is 35.453 amu?
    1. 2.767 x 10²³
    2. 1.244 x 10²⁴
    3. 8.172 x 10^-25
    4. 7.776 x 10¹⁵
    5. 3.107 x 10²³

18. What is the mass in grams of Zirconium (Zr) in 0.3384 mol of the mineral zircon, ZrSiO₄, given the atomic weights: Zr = 91.22 amu; Si = 28.09 amu; O = 16.00 amu?
    1. 30.87 g
    2. 21.66 g
    3. 9.36 g
    4. 273 g
    5. 97.6 g

19. What is the % by weight of carbon in ascorbic acid, C₆H₈O₆, also known as Vitamin C, given the atomic weights: C = 12.01 amu; H = 1.008 amu; O = 16.00 amu?
    1. 40.9%
    2. 4.58%
    3. 54.5%
    4. 30.0%
    5. 12.0%

20. What is the empirical formula of a compound that contains 87.5% N and 12.5% H by weight, given the atomic weights: N = 14.01 g; H = 1.008 g?
    1. N₂H₄
    2. NH₃
    3. NH₂
    4. N₂H₆
    5. N₂H

21. What is the mass of AlBr₃ in grams produced by the reaction of 1.5 mol of HBr according to the following equation:
    2Al + 6HBr --> 2AlBr₃ + 3H₂

    and given the atomic weights: Al = 26.98 amu; Br = 79.90 amu; H = 1.008 amu?

    1. 520 g
    2. 260 g
    3. 130 g
    4. 65.0 g
    5. 79.9 g

22. Which is the limiting reagent when 62.0 g of P₄ and 128 g of S₈ react according to:
    4P₄ + 5S₈ --> 4P₄S₁₀

    and given the atomic weights: P = 31.0 amu; S = 32.0 amu?

    1. P₄
    2. S₈
    3. not enough information
    4. neither P₄ nor S₈
    5. both P₄ and S₈

23. Magnesium metal burns in oxygen to form magnesium oxide, MgO. The theoretical yield of magnesium oxide from a reaction mixture containing 1.204 x 10²⁴ Mg atoms and 25.0 g oxygen gas is: [AW: Mg = 24.31; O = 16.00]
    1. 0.391 mol
    2. 0.781 mol
    3. 1.56 mol
    4. 2.00 mol
    5. 2.78 mol

24. What is the coefficient of O₂ appearing in the following equation when it is balanced with smallest whole numbers?
    C₆H₁₂O₆ + O₂ --> CO₂ + H₂O
    1. 1
    2. 2
    3. 6
    4. 9
    5. 18

25. A reaction occurs between sodium carbonate and hydrochloric acid producing sodium chloride, carbon dioxide and water. The correct coefficients for the balanced equation in the order of the substances given is:
    1. 3, 6, 6, 3, 4
    2. 8, 6, 5, 10, 5
    3. 5, 10, 10, 5, 5
    4. 1, 2, 2, 1, 1
    5. none of these

26. Apatite is a mineral that is found in tooth enamel. When fluoride toothpastes are used, this mineral is converted to fluoroapatite, which is more resistant to tooth decay. Keith is very dilligent at brushing his teeth, and as a result has 5.00 g of fluroapatite, Ca₅(PO₄)₃F in his teeth. What is the mass of oxygen in this amount of fluoroapatite? [Ca₅(PO₄)₃F = 504.5 g/mol]
    1. 0.635 g
    2. 1.11 g
    3. 1.90 g
    4. 6.40 g
    5. 540.45 g

27. Calculate the amount of phosphine, PH₃, that can be prepared when 10.0 g of calcium phosphide, Ca₃P₂ reacts with excess water.
    Ca₃P₂(s) + 6H₂O(l) --> 3Ca(OH)₂(aq) + 2PH₃(g)
    1. Not enough information given.
    2. 0.110 g
    3. 1.86 g
    4. 3.73 g
    5. 20.0 g

28. Scott reacts 10.0 g of hydrogen and 10.0 g of chlorine (in a safety hood, while wearing safety goggles). What is the mass of the hydrochloric acid that is produced?
    H₂(g) + Cl₂(g) --> 2HCl(g)
    1. 10 g
    2. 10.3 g
    3. 20.0 g
    4. 20.6 g
    5. 183 g

29. A mole of sodium nitrate (NaNO₃):
    1. contains 6.02 x 10²³ sodium nitrate units.
    2. contains 6.02 x 10²³ nitrogen atoms.
    3. weighs 85.0 g.
    4. contains 5 moles of atoms.
    5. All of the above are true.

30. The first substance to act as a superconductor at a temperature above 77 K has the molecular formula YBa₂Cu₃O₇. Calculate the percent composition by mass of the element Ba in this material.
    1. 16.8%
    2. 28.6%
    3. 41.2%
    4. 13.3%
    5. 17.6%

31. An unknown compound is made up of C, H, N and O. A 2.402-g sample of this compound contains 1.121 g of N, 0.161 g H, 0.480 g C, and an unspecified amount of oxygen. What is the empirical formula of the unknown compound?
    1. CH₄NO
    2. CH₄N₂O
    3. CH₄N₂O₂
    4. C₂H₈NO
    5. C₂H₈N₄O₂

32. How many hydrogen atoms are there in 1.0 x 10¹ g of glucose, C₆H₁₂O₆?
    1. 12
    2. 12 x 10²³
    3. 4.0 x 10²³
    4. 8.0 x 10²³
    5. 0.067

33. How many moles of Cr(s) are needed to balance the following equation?
    Cr(s) + S₈(s) --> Cr₂S₃(s)
    1. 2
    2. 4
    3. 6
    4. 8
    5. 16

34. The amount of copper in a certain alloy is determined by reacting the copper with sulfuric acid,
    Cu(s) + 2H₂SO₄(aq) --> CuSO₄(aq) + SO₂(g) + 2H₂O(l)

    and then precipitating solid CuI with KI solution,

    2CuSO₄(aq) + 5KI(aq) --> 2CuI(s) + KI₃(aq) + 2K₂SO₄(aq)

    What mass of copper was present if 4.86 g of CuI was recovered?

    1. 4.86 g
    2. 3.24 g
    3. 2.43 g
    4. 1.62 g
    5. 0.811 g

35. A mixture of 12.2 g of potassium and 22.2 g of bromine, Br₂, was heated until the reaction was completed. What mass of KBr is formed?
    1. 119 grams
    2. 22.2 grams
    3. 27.8 grams
    4. 33.1 grams
    5. 30.0 grams

36. When 12.0 g of hydrogen reacts with 12.0 g of chlorine,
    H₂(g) + Cl₂(g) --> 2HCl(g)

    5.53 g of hydrogen chloride are recovered. The percent yield of HCl is:

    1. 1.27%
    2. 2.55%
    3. 45.0%
    4. 89.9%
    5. 100%

37. After looking at this exam, you take a deep breath and inhale 1.16 x 10²² molecules of air, which is a mixture of several gases. Assume that the molar mass of air is 29.0 g/mol. What is the mass of air that you just inhaled?
    1. 10.0 grams
    2. 1.11 grams
    3. 0.558 grams
    4. 0.501 grams
    5. 0.279 grams

38. If the average mass of a single oxygen atom is 26.58 x 10^-24 g, what is the mass in grams of 6.02 x 10²³ oxygen atoms?
    1. 4.0 g
    2. 8.0 g
    3. 16.0 g
    4. 32.0 g
    5. 64.0 g

39. When the chemical equation describing the complete combustion of benzene, C₆H₆, with oxygen to form CO₂ and water is balanced, one can determine that the number of moles of oxygen consumed per mole of benzene is:
    1. 15
    2. 7.5
    3. 3
    4. 2
    5. the equation cannot be balanced for 1 mole C₆H₆

40. Iron(II) sulfate, FeSO₄, is prescribed for the treatment of anemia. How many moles of FeSO₄ are present in a standard 300 mg tablet?
    1. 1.57 x 10^-5 mol
    2. 3.57 x 10^-4 mol
    3. 2.97 x 10^-3 mol
    4. 1.97 x 10^-3 mol
    5. 1.97 mol

41. A hydrocarbon molecule consists of 90.0% C and 10.0% H by weight. Its molecular weight is 120 amu. How many atoms (carbon and hydrogen together) are there in this molecule?
    1. 19
    2. 20
    3. 21
    4. 22
    5. 23
    The next four questions refer to vanillin, C₈H₈O₃ (MW = 152.14). The equation representing the complete combustion of vanillin is:
    2C₈H₈O₃(l) + 17O₂(g) --> 16CO₂(g) + 8H₂O(g)

42. The number of carbon atoms in 1.3 mole of vanillin is:
    1. 8 atoms.
    2. 16 atoms.
    3. 7.8 x 10²³ atoms.
    4. 6.3 x 10²⁴ atoms.
    5. 1.3 x 10²⁵ atoms.

43. The percent by mass of oxygen in vanillin is:
    1. 63.16%.
    2. 31.55%.
    3. 15.79%.
    4. 5.30%
    5. none of the above

44. The theoretical yield of CO₂ from a reaction mixture containing 45.6 g of vanillin and 73.2 g O₂ is:
    1. 63.2 g.
    2. 94.8 g.
    3. 1.00 x 102 g.
    4. 118.6 g
    5. none of these

45. An unknown amount of vanillin was burned in a flask with excess O₂. The 67.3 g of CO₂ that was recovered is 76.9% of the theoretical yield. The original sample of vanillin had a mass of:
    1. 22.4 g
    2. 29.1 g
    3. 37.8 g
    4. 152 g
    5. 304 g

46. Combustion analysis of 45.62 mg of toluene, a commonly used hydrocarbon solvent gives 35.67 mg of H₂O and 152.5 mg of CO₂. What is the empirical formula of toluene?
    1. C₇H₈
    2. C₆H₆
    3. C₆H₈
    4. C₁₂H₁₆
    5. C₁₄H₁₆

47. What is the percentage of carbon in dimethylsulfoxide, C₂H₆SO?
    1. 7.74%
    2. 20.6%
    3. 30.7%
    4. 60.0%
    5. 79.8%

48. A compound of nitrogen and oxygen is analyzed, and a sample wieghing 1.587 g is found to contain 0.483 g N and 1.104 O. What is the empirical formula of the compound?
    1. NO
    2. NO₂
    3. N₂O₂
    4. N₂O₄
    5. N₂O₅

49. If the mass of a sulfur sample containing 1.0 x 10¹¹ atoms is 5.313 picograms, how much does 1 mole of sulfur weigh?
    1. 64 g
    2. 32 g
    3. 16 g
    4. 8.0 g
    5. 4.0 g

50. An unknown element, X, reacts with chlorine to form an ionic compound XCl₂. If the X ion has 18 electrons, the element X is:
    1. Al
    2. Ca
    3. Mg
    4. Na
    5. Si

51. How many grams of hydrogen are in 46 g of CH₄O?
    1. 0.36
    2. 1.5
    3. 2.8
    4. 4.0
    5. 5.8

52. When the equation:
    C₅₇H₁₁₀O₆ + O₂ --> H₂O + CO₂

    is balanced using smallest whole numbers, the coefficient of oxygen is:

    1. 1
    2. 3
    3. 84
    4. 163
    5. 338

53. Heptane (C₇H₁₆) combusts with O₂ to produce CO₂ and H₂O. If the theoretical yield of CO₂ is 247.8 g, how many grams of heptane are used in this reaction assuming unlimited quantity of O₂?
    C₇H₁₆ + 11O₂ --> 8H₂O + 7CO₂
    1. 80.62 g
    2. 100.2 g
    3. 161.2 g
    4. 564.3 g
    5. cannot be determined without knowing the amount of H₂O produced since it contains the hydrogen from heptane.

54. In an experiment, 7.36 g of zinc and excess sulfur, S₈, were mixed and heated. The substances react according to the following unbalanced chemical equation:
    Zn + S₈ --> ZnS

    The amount of zinc sulfide that can be produced by the reaction mixture is:

    1. 0.110 g
    2. 1.10 g
    3. 2.20 g
    4. 11.0 g
    5. 22.0 g
    The following two questions refer to the reaction:
    2C₂H₂(g) + 5O₂(g) --> 4CO₂(g) + 2H₂O(g)

55. If 10.0 g of C₂H₂ (molecular mass = 26.04 amu) and 10.0 g of O₂ (molecular mass = 32.00 amu) reacted, the mass of CO₂ that can be produced theoretically is numerically (in g):
    1. 5.50
    2. 11.0
    3. 16.9
    4. 33.8
    5. none of these

56. If, in fact, 5.50 g of CO₂ are actually produced, the percent yield (by weight) is numerically:
    1. 16.3
    2. 32.5
    3. 50.0
    4. 100.
    5. none of these

57. If 3 moles of HCl are added to 2 moles of NaOH and the following reaction proceeds, what will be in the reaction vessel when the reaction comes to completion (and the reaction is not reversible)?
    HCl + NaOH --> H₂O + NaCl
    1. H₂O and HCl
    2. HCl and NaCl
    3. H₂O and NaCl
    4. H₂O, NaCl, and HCl
    5. H₂O, NaCl, NaOH, and HCl

58. A substance was determined to be 49.9% oxygen, 37.5% carbon and 12.6% hydrogen by mass. What is the proper empirical formula for this compound?
    1. C₂H₃O
    2. CH₄O
    3. CH₂O
    4. CHO
    5. CH₃CO₂H

59. In lecture we reacted hydrogen and oxygen to form water. If 1.0 g of H₂ was reacted with 10.0 g of O₂, what is the amount of H₂O (in grams) that could be produced?
    2H₂(g) + O₂(g) --> 2H₂O(g)
    1. 4.0 g
    2. 8.0 g
    3. 9.0 g
    4. 11 g
    5. 16 g

60. Consider the following UNBALANCED combustion reaction:
    ___ CH₄ + ___ O₂ --> ___ CO₂ + ___ H₂O

    After balancing the reaction, if 4 mol of CH₄ is combusted with 4 mol of oxygen, how many moles of CH₄ are left over?

    1. 0
    2. 1
    3. 2
    4. 3
    5. 4

61. What is the stoichiometric coefficient for sulfuric acid in the following reaction?
    ___ Fe₂O₃(s) + ___ H₂SO₄ --> ___ Fe₂(SO₄)₃ + ___ H₂O
    1. 1
    2. 2
    3. 3
    4. 4
    5. 5

62. How much ammonia, NH₃, can be obtained from the reaction of 10.0 g of H₂ and 80.0 g of N₂?
    N₂ + 3H₂ --> 2NH₃
    1. 28.4 g
    2. 48.6 g
    3. 56.2 g
    4. 90.0 g
    5. 97.1 g

63. How many sodium atoms are in 6.0 g of Na₃N?
    1. 3.6 x 10²⁴
    2. 4.6 x 10²²
    3. 1.3 x 10²³
    4. 0.22
    5. 0.072

64. What is the coefficient of H₂O when the following reaction is properly balanced with the smallest integers?
    ___Na + ___H₂O --> ___NaOH + ___H₂
    1. 1
    2. 2
    3. 3
    4. 4
    5. 5

65. What is the mass percent composition of F in KrF₂? (molar mass = 121.80 g)
    1. 18.3%
    2. 145.3%
    3. 68.8%
    4. 81.5%
    5. 31.2%

66. What is the empirical formula of a compound that contains 15.94% boron and 84.06% fluorine by mass?
    1. BF
    2. BF₂
    3. B₂F₃
    4. BF₃
    5. B₃F₄

67. A certain compound was found to contain 67.6% C, 22.5% O, and 9.9% H. If the molecular weight of the compound was found to be approximately 142 g/mol, what is the correct molecular formula for the compound?
    1. C₅H₂O₅
    2. C₆H₆O₄
    3. C₇H₁₀O₃
    4. C₈H₁₄O₂
    5. C₈H₁₂O₂

68. If equal volumes (1.0 L each) of hydrogen and oxygen are mixed and ignited, what is the total volume (products and left over reactants) after reaction, assuming constant temperature and pressure? [Note: all reactants and products are gases]
    1. 1.0 L
    2. 1.5 L
    3. 2.0 L
    4. 2.5 L
    5. 3.0 L

69. For the following reaction, if 10.0 g of each reactant are available, how many grams of product will be produced? [Note, you will need to balance the reaction before solving.]
    _____Ca(s) + _____O₂(g) --> _____CaO(s)
    1. 5.43 g
    2. 7.94
    3. 14.0 g
    4. 20.0 g
    5. it cannot be determined

70. What is the product of this hypothetical reaction?
    3A₂B₃ + B₃ --> 6 ???
    1. AB
    2. AB₂
    3. AB₃
    4. A₂B
    5. A₃B

71. How many grams of water are produced in the combustion of 17.3 g of glucose (C₆H₁₂O₆) to form water and carbon dioxide? [MW: C₆H₁₂O₆ = 180.1]
    1. 10.4 g
    2. 17.3 g
    3. 18.4 g
    4. 21.2 g
    5. 34.6 g

72. If 30.0 g C₆H₆ (molecular weight, 78.11 amu) react with 65.0 g Br₂ (molecular weight, 159.80 amu) according to the reaction,
    C₆H₆ + Br₂ --> C₆H₅Br + HBr

    56.7 g C₆H₅Br (molecular weight, 157.0 amu) result. The percent theoretical yield of C₆H₅Br is numerically:

    1. 38.4
    2. 40.7
    3. 88.7
    4. 94.0
    5. None of these are close to the correct answer.

73. Commercial bronze, an alloy of Zn and Cu, reacts with hydrochloric acid as follows:
    Zn(s) + 2HCl(aq) --> ZnCl₂(aq) + H₂(g)

    Copper does not react with HCl. When 0.507 g of bronze reacts with excess HCl, 0.0985 grams of ZnCl₂ is produced. The % by mass of Zn in bronze is closest to:

    1. 9.34%
    2. 19.34%
    3. 30.34%
    4. 69.66%
    5. 90.66%

74. When 2 moles of KOH are added to 3 moles of HI and the following reaction proceeds, what will be in the final mixture when the reaction comes to completion? (The reaction is not reversible.)
    KOH + HI --> KI + H₂O
    1. HI and KI
    2. KI and H₂O
    3. HI and H₂O
    4. HI, KI and H₂O
    5. KOH, HI, KI and H₂O

75. The reaction between oxygen and carbon monoxide can be represented by the following equations:
    1/2O₂(g) + CO(g) --> CO₂(g)
    O₂(g) + 2CO(g) --> 2CO₂(g)

    Consider an initial reaction mixture as shown in the following diagram:

    

    Assuming that the reaction illustrated above goes to completion, the product mixture can be represented by:

    

76. Magnesium metal burns in oxygen to form magnesium oxide, MgO. The theoretical yield of magnesium oxide from a reaction mixture containing 1.204 x 10²⁴ Mg atoms and 25.0 g oxygen gas is: [AW: Mg = 24.31; O = 16.00]
    1. 0.391 mol.
    2. 0.781 mol.
    3. 1.56 mol.
    4. 2.00 mol.
    5. 2.78 mol.

77. How many moles of ions are there per mole of Al₂(SO₄)₃?
    1. 17
    2. 6
    3. 5
    4. 3
    5. 1

78. A fuel mixture of two liquids, hydrazine (N₂H₄) and dinitrogen tetraoxide (N₂O₄) ignite to form nitrogen gas and water vapor. How many grams of nitrogen gas form when exactly 100.0 g N₂H₄ and 200.0 g of N₂O₄ are mixed? (Assume the reaction goes to completion.)
    1. 662 g N₂
    2. 331 g N₂
    3. 183 g N₂
    4. 131 g N₂
    5. 31 g N₂

79. The elemental analysis of a sample of ionic compound gave the following results: 2.82 g Na, 4.35 g Cl, and 7.83 g O. The empirical formula of this compound is:
    1. Na_0.12ClO₂
    2. NaClO₂
    3. NaClO₃
    4. NaClO₄
    5. Na₂ClO₄

80. The chief ore of manganese is an oxide known as pyrolusite, which is 36.8% O and 63.2% Mn by mass. Which of the following oxides of manganese is pyrolusite? [At Wts: O = 16.00 amu; Mn = 54.94 amu]
    1. MnO
    2. MnO₂
    3. Mn₂O₃
    4. MnO₃
    5. Mn₂O₇

81. Calculate the mass of CO₂ produced when 10.0 g of methane (CH₄) are burned. [At Wts: C = 12.01 amu; H = 1.008 amu; O = 16.00 amu]
    1. 17.4 g
    2. 10.0 g
    3. 24.7 g
    4. 27.4 g
    5. 4.76 g

82. How many atoms of oxygen are in 2.00 mole of NaAl(OH)₂CO₃?
    1. 4
    2. 5
    3. 5.00 x 10²³
    4. 6.02 x 10²³
    5. 6.02 x 10²⁴

83. What is the mass of magnesium oxide (MgO) formed when 10.0 g of Mg react with 10.0 g of O₂ according to the reaction:
    2Mg + O₂ --> MgO
    1. 0.411 g
    2. 6.58 g
    3. 25.2 g
    4. 16.6 g
    5. 97.2 g

84. What is the average atomic mass of an iron atom in grams (atomic mass Fe = 55.85 amu)?
    1. 6.02 x 10²³
    2. 1.66 x 10^-24
    3. 9.28 x 10^-23
    4. 55.85
    5. 55.85 x 10^-23

85. What is the mass percentage of nitrogen in nicotine, C₁₀H₁₄N₂ (molar mass = 162.23 g)?
    1. 8.64%
    2. 9.46%
    3. 13.2%
    4. 17.3%
    5. 21.7%

86. What is the empirical formula of a compound that contains 63.65% N and 36.35% O by mass?
    1. NO
    2. NO₂
    3. N₂O
    4. N₂O₄
    5. N₂O₃

87. How many moles of H₂O are produced when 2.5 moles of O₂ react in the following balanced reaction?
    C₃H₈ + 5O₂ --> 3CO₂ + 4H₂O
    1. 5.0
    2. 4.0
    3. 3.0
    4. 2.5
    5. 2.0

Answers

1. A
2. D
3. A
4. B
5. A
6. E
7. D
8. C
9. D
10. D
11. A
12. C
13. C
14. C
15. E
16. B
17. E
18. A
19. A
20. C
21. C
22. B
23. B
24. C
25. D
26. C
27. D
28. B
29. E
30. C
31. B
32. C
33. E
34. E
35. D
36. C
37. C
38. C
39. B
40. D
41. C
42. D
43. B
44. B
45. C
46. A
47. C
48. B
49. B
50. B
51. E
52. D
53. A
54. D
55. B
56. C
57. D
58. B
59. C
60. C
61. C
62. C
63. C
64. B
65. E
66. D
67. D
68. B
69. C
70. B
71. A
72. D
73. A
74. D
75. B
76. C
77. C
78. D
79. D
80. B
81. D
82. E
83. D
84. C
85. D
86. C
87. E