Practice Exam #2
(Answers are at the end)
MULTIPLE CHOICE: Put a circle around the letter corresponding to the best answer.
1. The inertness of the noble gases is due to:
A. the unique structure of their nucleus B. the special number of protons and neutrons
C. the bonds they form with other elements D. the number and arrangement of their electrons
2. A sodium ion, Na+, has the same electron configuration as a(n):
A. sodium atom B. chlorine atom C. neon atom D. argon atom
3. The number of protons in a sodium ion, Na+, is:
A. ten B. eleven C. twelve D. twenty-three
4. With respect to chemical bonding, which particles play the most active
A. protons B. neutrons C. valence electrons D. core electrons
5. Which of the noble gases does not have an octet of electrons in the
A. He B. Ne C. Ar D. Kr
6. Which atom is least likely to form an ion?
A. chlorine B. sodium C. carbon D. oxygen
7. Which substance has ionic bonds?
A. Cl2 B. NH3 C. H2O D. KBr
8. In a nonpolar covalent bond, electrons are:
A. shared equally B. shared unequally C. transferred D. uncharged
9. Which substance has nonpolar covalent bonds?
A. O2 B. NO2 C. NaCl D. CO
10. In a molecule of N2, the nitrogen atoms are
bonded to each other by:
A. an ionic bond B. a single covalent bond C. a double covalent bond
D. a triple covalent bond
11. Which state of matter is characterized by having molecules far apart
and moving randomly?
A. gas B. liquid C. solid D. all of these
12. What type of force exists between oxygen molecules in liquid oxygen?
A. hydrogen bonding B. dipole forces C. dispersion forces D. all of these
13. Water is a liquid at room temperature while methane is a gas. Which
statement compares the intermolecular forces in these molecules correctly?
A. The intermolecular forces in methane are stronger than those in water.
B. The intermolecular forces in water are stronger than those in methane.
C. Both water and methane have the same intermolecular forces.
D. There is not enough information to compare these forces.
14. What is the name of the compound with the formula SO3?
A. sulfur(VI) oxide B. sulfur oxide(III) C. sulfur trioxide D. sulfur(I) oxide(III)
15. The volume occupied by 0.200 mol of nitrogen gas at 1.00 atm pressure
and 27oC is:
A. 0.44 L B. 4.9 L C. 22.4 L D. 0.0821 L
16. Many medicines have a bitter taste which manufacturers attempt to
disguise. Many medicines are probably:
A. acids B. bases C. salts D. neutral
17. H3O+ is called the
A. hydrate ion B. hydrogen ion C. hydroxide ion D. hydronium ion
18. When added to water, which of the following would produce an acid?
A. Na B. MgO C. NH3 D. SO3
19. All of the following are bases except:
A. KOH B. HNO3 C. NH3 D. Mg(OH)2
20. A useful broad view of reactions between acids and bases involves
A. transfer of protons B. transfer of electrons
C. conversion of protons intoelectrons D. ionization of atoms
21. HCN is classified as a weak acid in water. This means it produces:
A. no hydronium ions
B. a relatively small fraction of the maximum number of possible hydronium ions
C. a relatively large fraction of the maximum number of possible hydronium ions
D. 100% of the maximum number of possible hydronium ions
22. When an aqueous solution containing hydrochloric acid is just neutralized
with an aqueous solution containing sodium hydroxide, the solution would
A. sour B. bitter C. salty D. sweet
23. A sample of rainwater has a pH of 3.5. What ion is sure to be present
in relatively large concentration in this rain sample?
A. H3O+ B. SO42- C. OH- D. HSO4-
24. Which of the following is not responsible for acid rain?
A. CO2 B. NH3 C. NO2 D. SO2
25. In the reaction C6H5OH + H2O --->
C6H5O- + H3O+ the
compound C6H5OH is a(n):
A. acid B. base C. salt D. ionic compound
26. Which of the following abbreviations stands for a unit of length?
A. dm B. Mg C. cc D. mL
27. The kind of science that pursues knowledge for its own sake is called:
A. technology B. applied research C. basic research D. ecology
28. The fact that 20 grams of hydrogen combines with 160 grams of oxygen
to form water and 20 grams of hydrogen also combine with 320 grams of oxygen
to form hydrogen peroxide, illustrates the law of:
A. continuity of matter B. indivisibility of atoms C. multiple proportions
D. definite proportions
29. The nucleus of an atom contains:
A. all of the positive charge, most of the mass
B. all of the negative charge, most of the mass
C. all of the positive charge, none of the mass
D. all of the negative charge, none of the mass
30. A beta particle has the same mass and charge as:
A. a neutron B. a gamma ray C. an electron D. a proton 31.
The electron configuration of an oxygen atom is:
A. 1s22s22p6 B. 1s22s22p3 C. 1s22s22p63s2 D. 1s22s22p4
32. Write the electron dot symbol for a single atom of nitrogen.
33. Write the formula for the compound formed when magnesium reacts with oxygen.
34. Draw the Lewis electron dot structure for carbon monoxide.
35. What is the name of the compound whose chemical formula is AlCl3?
36. What is the chemical formula for silver(I) sulfate?
37. What is the chemical formula for iron(III) carbonate?
38. What is the name of the compound with the formula K2S?
39. What is the name of the compound with the formula CCl4?
40. What is the name of the compound with the formula N2O4?
41. Balance the following chemical equation:
AlCl3 + H2SO4 ----> Al2(SO4)3 + HCl
42. Balance the following chemical equation:
C8H18 + O2 ---> CO2 + H2O
43. Write a balanced chemical equation for the neutralization of calcium hydroxide with nitric acid (HNO3).
44. The pH of a sample of water from a river is 6.0. A sample of effluent
from a food processing plant
has a pH of 4.0.
How many times larger is the molar concentration of hydrogen ion in the effluent compared to the river?
45. How many centigrams are there in 18 kg?
46. Write an equation representing the beta decay of lead-209.
47. Ionic compounds generally form between metals and nonmetals.
48. The formula for an oxide ion is O6+.
49. When magnesium combines with oxygen, the bond formed is best classified as polar covalent.
50. Covalent bonds generally form between metals.
51. A measure of the tendency of an atom in a molecule to attract electrons to itself is called affinity.
52. Atoms and molecules with odd numbers of electrons are called free radicals.
53. The shape of a methane molecule, CH4, is best described as triangular.
54. The process by which a gas is converted to a liquid is called vaporization.
55. Aspirin has a formula C9H8O4. The molar mass of aspirin is 180.0 g.
56. When potassium oxide is added to water, potassium hydroxide forms.
57. An aqueous solution whose pH is ten has a hydrogen ion concentration of 10 mol/L.
58. All antacids are bases.
59. The acid in stomach fluid is ascorbic acid.
60. Chemical bond energies are larger than nuclear bond energies.
61. 13N is an isotope of carbon-12.
62. A substance which conducts electricity when dissolved in water is called an alkali.
FOR QUESTIONS 63-67, YOU MUST SHOW YOUR CALCULATION SETUPS OR EXPLAIN
YOUR REASONING TO RECEIVE FULL CREDIT. EXPRESS ALL ANSWERS TO THE PROPER
NUMBER OF SIGNIFICANT FIGURES.
63. When two liters of hydrogen gas and one liter of oxygen gas react to form water at a constant temperature and pressure, how many liters of water vapor (steam) will be formed?
64. How many molecules are in 237 grams (about a cup) of water?
65. What is the density of helium gas at STP in grams per liter?
66. A balloon is inflated outdoors on a cold day in North Dakota at a temperature of -40oC to a volume of 2.00 L. Assuming the pressure remains constant, what is the volume of the balloon indoors at a temperature of 25oC?
67. In the reaction CH4 + 2O2 ---> CO2 + 2H2O, how many grams of oxygen are required to burn 8.0 grams of methane?
1. D 2. C 3. B 4. C 5. A 6. C 7. D 8. A 9. A 10. D 11. A 12. C 13. B 14. C 15. B 16. B
17. D 18. D 19. B 20. A 21. B 22. C 23. A 24. B 25. A 26. A 27. C 28. D 29. A 30. C 31. D
32. (should show N with 5 dots) 33. MgO 34. : C(triple bond)O: 35. aluminum chloride 36. Ag2SO4
37. Fe2(CO3)3 38. potassium sulfide 39. carbon tetrachloride 40. dinitrogen tetroxide
41. 2 AlCl3 + 3 H2SO4 ---> Al2(SO4)3 + 6HCl 42. 2 C8H18 + 25 O2 ----> 16CO2 + 18 H2O
43. Ca(OH)2 + 2 HNO3 ----> Ca(NO3)2 + 2 HOH
44. 10-6 compared to 10-4 100 times larger 45. 1.8 x 106 cg
Pb ----> e + Bi
82 -1 83
47. true 48. false, O2- 49.false, ionic 50. false, nonmetals 51. false, electronegativity
52. true 53. false, tetrahedral 54. false, condensation 55. true 56. true 57. false, 10-10
58. true 59. false, hydrochloric 60. false, smaller 61. false, 13C 62. false, electrolyte
63. 2 liters
64. 7.93x1024 molecules of water
65. 0.18 g/L 66. 2.56L
67. 32 grams O2