Chapter 3 1 Single Molecule Polystryene Has The Repeating Unit

Chapter 3 – Calculations with Chemical Formulas and Equations

1. The molecular formula of a particular solid is C8H6O8. Its molecular mass is

A)

352 amu.

B)

118 amu.

C)

364 amu.

D)

230 amu.

E)

226 amu.

2. The hydrocarbon heptane has the structural formula CH3(CH2)5CH3. What is the molecular

mass of this hydrocarbon?

A)

100.2 amu.

B)

0.009980 amu.

C)

86.17 amu.

D)

0.01160 amu.

E)

110.2 amu.

3. A single molecule of polystryene has the repeating unit -[CH2CH(C6H5)]n-, where n is the

number of repeating units. What is the value of n if the molecular mass of a single polymer

chain is

1.5782 106

amu?

A)

1.515 104

units.

B)

1.644 108

units.

C)

3.031 104

units.

D)

2.047 104

units.

E)

1.217 108

units.

4. The formula mass of aluminum oxalate, Al2(C2O4)3, is

A)

140 amu.

B)

318 amu.

C)

283 amu.

D)

213 amu.

E)

185 amu.

5. The formula mass of zinc acetate trihydrate, Zn(CH3COO)2 • 3H2O, is

A)

321 amu.

B)

184 amu.

C)

268 amu.

D)

238 amu.

E)

114 amu.

6. The fully hydrated form of sodium sulfate is the decahydrate, Na2SO4 • 10H2O. When

heated the hydrated salt loses water. How many water molecules are found per formula unit

in a partially dehydrated sample of sodium sulfate with a formula mass of 160.1 amu (i.e.

find n for Na2SO4 • nH2O)?

A)

1 waters.

B)

5 waters.

C)

3 waters.

D)

4 waters.

E)

7 waters.

7. What is the molecular mass of cycloheptane, C7H14?

A)

13.02 amu

B)

1191.19 amu

C)

85.08 amu

D)

98.19 amu

E)

26.12 amu

8. What is the formula mass of strontium phosphate, Sr3(PO4)2?

A)

357.83 amu

B)

421.83 amu

C)

182.59 amu

D)

715.66 amu

E)

452.80 amu

9. What is the molecular mass of the hydrocarbon styrene (shown in the figure)?

A)

104.1 amu.

B)

91.1 amu.

C)

103.1 amu.

D)

13.0 amu.

E)

78.1 amu.

10. What is the molar mass of ammonium sulfite, (NH4)2SO3?

A)

98 g/mol

B)

116 g/mol

C)

55 g/mol

D)

180 g/mol

E)

84 g/mol

11. What is the molar mass of zinc sulfate heptahydrate, ZnSO4 • 7H2O?

A)

180. g/mol

B)

288 g/mol

C)

384 g/mol

D)

162 g/mol

E)

582 g/mol

Test Bank General Chemistry, 10th edition 4

12. Plastic wrap can be made from poly(vinylidene chloride). A single poly(vinylidene

chloride) strand has the general formula -(CH2CHCl)n-, where n ranges from 10,000 to

100,000. What is the molar mass of a single poly(vinylidene chloride) molecule containing

6.928 104

repeating units?

A)

4.330 106

g/mol

B)

2.706 106

g/mol

C)

2.310 10−7

g/mol

D)

6.308 106

g/mol

E)

1.585 10−7

g/mol

13. The dicarboxylic acid potassium hydrogen pthalate (shown in the figure) is used to

standardize solutions of strong base. What is the molar mass of this compound?

A)

204.2 g/mol

B)

192.2 g/mol

C)

248.9 g/mol

D)

71.08 g/mol

E)

172.2 g/mol

14. What is the molar mass of the solid C8H12N2O4?

A)

172 g/mol

B)

136 g/mol

C)

200 g/mol

D)

106 g/mol

E)

188 g/mol

15. A 1.067 g sample of an element contains 5.062  1021 atoms. What is the element symbol?

A)

I

B)

Ag

C)

La

D)

Pd

E)

Rh

16. Monodisperse polyacrylonitrile contains molecules with the general formula -(CH2CHCN)n–

, where n is typically greater than 10,000. Given that a sample of monodisperse

polyacrilonitrile weighs 197.4 g and contains

1.046 1020

molecules of -(CH2CHCN)n-,

calculate n.

A)

2.141 104

B)

6.026 107

C)

6.018 1039

D)

6.022 1023

E)

1.136 106

17. Monodisperse polyacrylonitrile contains molecules with the general formula -(CH2CHCN)n–

, where n is typically greater than 10,000. Given that a sample of monodisperse

polyacrylonitrile weighs 252.6 g and contains

4.443 1019

molecules of -(CH2CHCN)n-,

what is the molar mass of the polymer?

A)

6.452 104

g/mol

B)

1.816 108

g/mol

C)

1.997 1039

g/mol

D)

6.022 1023

g/mol

E)

3.423 106

g/mol

18. An atom of an element weighs 3.00  10–23 g. What is the atomic mass of this element in

atomic mass units?

A)

17.4 amu

B)

16.5 amu

C)

15.9 amu

D)

18.1 amu

E)

15.3 amu

19. What is the mass in grams of one propene, C3H6, molecule?

A)

6.99  10–23 g

B)

2.53  1025 g

C)

44.0 g

D)

42.0 g

E)

1.99  10–23 g

20. What is the mass of oxygen in grams found in one molecule of the compound C7H8O4?

A)

1.06 10−22

g

B)

3.86 1021

g

C)

1.34 10−23

g

D)

1.40 10−22

g

E)

156 g

21. Which of the following compounds contains the largest number of atoms?

A)

4.0 mol of K2S

B)

3.0 mol of NH3

C)

2.0 mol of H2SO4

D)

5.0 mol of HCl

E)

1.0 mol of CH3COCl

22. How many atoms of carbon are there in 0.51 mol of procaine, C13H20N2O2, a “pain killer”

used by dentists?

A)

6.6  1023

B)

4.3  1024

C)

4.0  1024

D)

6.1  1023

E)

4.6  1024

Test Bank General Chemistry, 10th edition 7

23. A sample of ammonium phosphite, (NH4)3PO3, contains 0.909 mol of hydrogen atoms. The

number of moles of oxygen atoms in the sample is

A)

0.227 mol.

B)

0.0909 mol.

C)

0.300 mol.

D)

0.227 mol.

E)

3.00 mol.

24. A sample of gallium(III) sulfite, Ga2(SO3)3, contains 1.95 mol of sulfite ions. The number of

moles of gallium(III) ions in the sample is

A)

1.30 mol.

B)

2.92 mol.

C)

1.95 mol.

D)

5.84 mol.

E)

3.90 mol.

25. Sorbose, C6H12O6, is used in making vitamin C. A sorbose sample containing 96.0 g of

carbon atoms also contains ____ g of hydrogen atoms.

A)

32.2

B)

16.1

C)

1.15  103

D)

96.0

E)

7.99

26. Consider the following three samples.

A. A sample containing 180 g glucose (C6H12O6)

B. A sample containing 90 g glucose and 90 g fructose (C6H12O6)

C. A sample containing 180 g fructose

Which statement is correct?

A)

All three samples have the same number of hydrogen atoms.

B)

Both samples A and C have the same number of hydrogen atoms, but more than in

sample B.

C)

Sample B has more hydrogen atoms than sample A or sample C.

Test Bank General Chemistry, 10th edition 8

D)

Sample C has more hydrogen atoms than sample A or sample B

E)

Sample A has more hydrogen atoms than sample B or sample C.

27. Styrene’s empirical formula is CH. What mass of styrene contains 7.89  1021 atoms of

hydrogen? The molar mass of styrene is 104 g/mol.

A)

0.105 g

B)

0.170 g

C)

1.36 g

D)

0.157 g

E)

0.0131 g

28. What is the mass of oxygen atoms in 0.305 mol Fe(CO)5?

A)

17.0 g

B)

59.7 g

C)

24.4 g

D)

4.88 g

E)

18.3 g

29. What is the mass in grams of 0.699 mol of glucose, C6H12O6?

A)

0.00388 g

B)

67.1 g

C)

126 g

D)

21.0 g

E)

258 g

30. Which one of the following samples has the greatest mass?

A)

0.39 mol of camphor, C10H16O

B)

4.1 mol of ammonia, NH3

C)

9.2 mol of krypton, Kr

D)

4.6 mol of iodine vapor, I2

E)

1.8 mol of formaldehyde, CH2O

31. Which of the following contains the greatest mass of oxygen atoms?

A)

0.6 mol CoSO4 • 7H2O

B)

2.3 mol KHSO4

C)

1.2 mol K2Cr2O7

D)

2.3 mol H2O2

E)

2.3 mol Na2S2O3

32. Calculate the number of moles of bromine present in 14.5 mL of Br2(l), whose density is

3.12 g/mL.

A)

3.53 mol

B)

0.181 mol

C)

0.566 mol

D)

0.091 mol

E)

0.283 mol

33. How many moles of hexachlorobenzene, C6Cl6, are in 4.45 g of C6Cl6?

A)

0.0208 mol

B)

1.27  103 mol

C)

0.0618 mol

D)

0.0156 mol

E)

0.0322 mol

34. How many moles of iron atoms are contained in 4.39 g of iron?

A)

245 mol

B)

0.0579 mol

C)

0.0786 mol

D)

0.122 mol

E)

0.169 mol

35. How many moles of pentane, C5H12, are contained in a 11-g sample?

A)

0.18 mol

B)

0.15 mol

C)

0.26 mol

D)

1.4 mol

E)

1.1 mol

36. Sodium cyclamate, C6H11NHSO3Na, was used at one time as an artificial sweetener.

C6H11NHSO3Na has a molecular mass of 201.2 g/mol. How many moles of sodium

cyclamate are contained in a 67.6-g sample?

A)

0.211 mol

B)

0.193 mol

C)

0.336 mol

D)

0.307 mol

E)

13,600 mol

37. How many moles of silver are contained in 7.00 kg of silver?

A)

64.9 mol

B)

64.9  101 mol

C)

64.9  10–3 mol

D)

64.9  103 mol

E)

64.9  10–1 mol

38. A 0.0103-mol sample of urea, NH2CONH2, contains

A)

6.02  1023 molecules.

B)

2.48  1022 molecules.

C)

4.96  1022 atoms.

D)

2.48  1023 atoms.

E)

1.03  1024 atoms.

39. How many molecules are there in 90.0 g of butylene glycol, HO(CH2)4OH?

A)

1

B)

(6.02  1023)/90.0

C)

90.0

D)

90.0  (6.02  1023)

E)

6.02  1023

40. How many molecules are there in 192 g of citric acid, C6H8O7?

A)

(6.02  1023) / 192

B)

192

C)

6.02  1023

D)

96.0

E)

192  (6.02  1023)

41. In 0.358 mol of trimellitic acid, C6H3(COOH)3, there are

A)

2.16  1022 molecules.

B)

8.62  1024 molecules.

C)

6.47  1023 oxygen atoms.

D)

1.94  1024 carbon atoms.

E)

3.59  1023 hydrogen atoms.

42. How many molecules are there in 2.80 kg of hydrazine, N2H4?

A)

8.75  1023

B)

5.27  1025

C)

1.88  1022

D)

2.80  1026

E)

4.65  1021

43. How many molecules are there in 2.43 mg of mannose, C6H12O6, which is a sweet-tasting

sugar that has a bitter aftertaste?

A)

4.46  1021

B)

2.48  1021

C)

7.31  1018

D)

4.04  1024

E)

8.13  1018

44. How many atoms are present in 463 g of KPF6 (MM = 184.1 g/mol)?

A)

2.23  1025

B)

1.51  1021

C)

2.51  1021

D)

1.13  1026

E)

1.21  1025

45. Styrene’s empirical formula is CH. When it is heated to 200°C, it is converted into a

polymer, polystyrene, which has excellent insulating properties. What mass of styrene

contains 9.75  1021 molecules of styrene? The molar mass of styrene is 104 g/mol.

A)

0.0162 g

B)

1.68 g

C)

3.24 g

D)

0.210 g

E)

0.130 g

46. In 0.500 mol of dimethylhydrazine, (CH3)2N2H2, there are

A)

3.01  1024 molecules.

B)

1.51  1023 atoms.

C)

3.01  1022 molecules.

D)

3.61  1024 atoms.

E)

1.81  1024 atoms.

47. Which is a reasonable mass corresponding to 1020 molecules of a substance?

A)

100 g

B)

100 µg

C)

100 ng

D)

100 mg

E)

100 kg

48. How many aluminum atoms are there in 52 g of Al2S3?

A)

4.2  1023

B)

1.6  1021

C)

2.1  1023

D)

1.1  1021

E)

6.3  1023

49. Which one of the following contains 2.41  1024 atoms?

A)

52.0 g C2H2

B)

96.0 g O2

C)

32.0 g CH4

D)

168 g N2

E)

16.0 g He

50. A sample of 496 g of white phosphorus, P4, contains the same number of atoms as

A)

192 g of ozone (O3).

B)

56.0 g of nitrogen (N2).

C)

92.0 g of sodium.

D)

120 g of formaldehyde (CH2O).

E)

128 g of oxygen (O2).

Test Bank General Chemistry, 10th edition 14

51. The total number of oxygen atoms in 1.76 g of CaCO3 (MM = 100.0 g/mol) is

A)

2.05  1023.

B)

4.24  1022.

C)

3.18  1022.

D)

1.75  1023.

E)

5.30  1022.

52. A sample of 336 g of ozone, O3, contains the same number of atoms as

A)

336 g of oxygen (O2).

B)

28.2 g of hydrogen (H2).

C)

266 g of fluorine (F2).

D)

189 g of aluminum (Al).

E)

411 g of nickel (Ni).

53. Which of the following samples contains the smallest number of molecules?

A)

8.00 g of TNT, C7H5N3O6

B)

8.00 g of benzene, C6H6

C)

8.00 g of glucose, C6H12O6

D)

8.00 g of naphthalene, C10H8

E)

8.00 g of formaldehyde, CH2O

54. Which of the following samples contains the largest number of atoms?

A)

1 g N2

B)

1 g Li

C)

1 g Cl2

D)

1 g P4

E)

1 g Mg

55. Which of the following samples contains the largest number of molecules?

Test Bank General Chemistry, 10th edition 15

A)

10. g Pb

B)

10. g Cl2

C)

10. g Kr

D)

10. g O2

E)

10. g S8

56. In 1928, 1.0 g of rhenium, Re, was isolated from 660 kg of the ore molybenite. The percent

by mass of this element in the molybenite was

A)

0.66 %.

B)

0.15 %.

C)

3.5  10–4 %.

D)

6.6  10–3 %.

E)

1.5  10–4 %.

57. An ore sample is found to contain 24.1 g of mercury and 50.7 g waste rock (gangue). What

is the percent by mass of mercury in the ore?

A)

32.2 %

B)

47.4 %

C)

0.322 %

D)

0.474 %

E)

4.74 %

58. An ore sample with a mass of 68.0 g is found to contain 15.5% by mass nickel. What mass

of nickel is contained in the ore?

A)

10.5 g

B)

81.7 g

C)

1.55 g

D)

84.5 g

E)

546 g

59. What is the percent by mass oxygen in (NH4)2SO3?

Test Bank General Chemistry, 10th edition 16

A)

41.3 %

B)

20.7 %

C)

54.0 %

D)

42.0 %

E)

1.00 %

60. What is the percentage by mass of hydrogen in the insecticide Lindane, C6H6Cl6?

A)

20.0 %

B)

1.20 %

C)

47.2 %

D)

8.80 %

E)

2.08 %

61. The mineral leadhillite, which is essentially Pb4(SO4)(CO3)2(OH)2 (FW = 1079 g/mol),

contains ____% hydrogen by mass.

A)

76.81

B)

0.1868

C)

2.226

D)

17.79

E)

2.972

62. Which of the following compounds has the highest percentage of hydrogen atoms by mass?

A)

CH3COOH

B)

C2H5OH

C)

CH3OH

D)

H2CO3

E)

H2C2O4

63. Which of the following compounds has the highest percentage of nitrogen by mass?

A)

(NH4)2SO3

B)

NaNO3

Test Bank General Chemistry, 10th edition 17

C)

N2Cl4

D)

NH4NO2

E)

HNO3

64. Which of the following compounds has the same percentage of carbon and hydrogen by

mass as cyclohexane, C6H12?

A)

C6H14, hexane

B)

C5H10, pentene

C)

C6H10, cyclohexene

D)

C6H6, benzene

E)

C6H12O6, glucose

65. What is the mass percentage of carbon in the compound C6H6O2?

A)

5.5 %

B)

70.9 %

C)

65.5 %

D)

29.1 %

E)

14.3 %

66. What is the percentage by mass of hydrogen in ammonium phosphate, (NH4)3PO4?

A)

8.11 %

B)

4.06 %

C)

52.0 %

D)

40.0 %

E)

3.00 %

67. A crystal of the mineral troegerite, (UO2)3(AsO4)2 • 12H2O (FM = 1304 amu), contains

____% arsenic by mass.

A)

15.4

B)

39.8

C)

61.0

Test Bank General Chemistry, 10th edition 18

D)

26.4

E)

11.5

68. How many grams of hydrogen atoms are present in 18.4 g of water?

A)

37.1 g

B)

1.02 g

C)

2.06 g

D)

1.96 g

E)

12.3 g

69. How many grams of potassium are present in 21.6 g of K2Cr2O7?

A)

5.74 g

B)

1.105 g

C)

2.87 g

D)

78.2 g

E)

10.8 g

70. NaHCO3 is the active ingredient in baking soda. How many grams of oxygen are present in

0.67 g of NaHCO3?

A)

0.024 g

B)

0.128 g

C)

7.98  103 g

D)

0.043 g

E)

0.38 g

71. Which of the following contains the greatest mass of bromine atoms?

A)

11.0 g of KBr

B)

23.0 g of Br2

C)

0.076 mol of KBr

D)

0.092 mol of Br2

E)

32.0 g of NaBrO3

Test Bank General Chemistry, 10th edition 19

72. The amount of calcium in a 15.0-g sample was determined by converting the calcium to

calcium oxalate, CaC2O4. The CaC2O4 weighed 12.6 g. What is the percent of calcium in

the original sample?

A)

10.8 %

B)

26.3 %

C)

14.8 %

D)

33.7 %

E)

84.0 %

73. A compound containing only carbon, hydrogen, and oxygen is subjected to elemental

analysis. Upon complete combustion, a 0.1804-g sample of the compound produced

0.3051 g of CO2 and 0.1249 g of H2O. What is the empirical formula of the compound?

A)

C3H6O3

B)

C3H3O

C)

C4H8O3

D)

C2H2O

E)

CH2O3

74. A 3.075 g sample of a compound containing only carbon, hydrogen, and oxygen is burned

in an excess of dioxygen, producing 6.990 g CO2 and 2.862 g H2O. What mass of oxygen is

contained in the original sample?

A)

0.8472 g

B)

1.167 g

C)

3.915 g

D)

4.129 g

E)

0.2134 g

75. A 4.043 g sample of a compound containing only carbon, hydrogen, and oxygen is burned

in an excess of dioxygen, producing 9.191 g CO2 and 3.762 g H2O. What percent by mass

of oxygen is contained in the original sample?

A)

27.54 %

B)

37.96 %

C)

12.73 %

D)

13.43 %

E)

6.939 %

76. A 2.841 g sample of a hydrocarbon is burned in an excess of dioxygen, producing 7.794 g

CO2 and water. What mass of hydrogen is contained in the original sample?

A)

0.7140 g

B)

4.953 g

C)

10.64 g

D)

2.826 g

E)

1.421 g

77. A 2.445 g sample of a hydrocarbon is burned in an excess of dioxygen, producing 6.708 g

CO2 and 5.492 g H2O. What is the empirical formula of the hydrocarbon?

A)

CH4

B)

CH2

C)

C2H3

D)

CH3

E)

CH

78. A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen

was burned in dioxygen to yield 0.01962 mol of CO2 and 0.01961 mol of H2O. What is the

empirical formula of the compound?

A)

CHO

B)

C3H3O2

C)

C2H2O

D)

C3H6O2

E)

C6H3O2