Download Final Review 2006

CP Final Review
Multiple Choice
Moles
____ 1. How many grams are there in 2.50 moles of chromium?
a. 41.6 g
c. 130.0 g
b. 20.8 g
d. 60.0 g
_____2. The molar mass of aluminum sulfate is _____.
a. 123 g/mol
b. 214 g/mol
c. 278 g/mol
d. 342 g/mol
____
3. Which one of the following compounds has the lowest molar mass?
a. Carbon monoxide.
c. Carbon dioxide.
b. Nitrogen dioxide.
d. Nitrogen monoxide.
____
4. How many oxygen atoms are there in 0.25 mole of oxygen gas?
a. 3.011 x 1023
c. 1.556 x 1023
b. 6.022 x 1023
d. 1.204 x 1024
____
5. A chemical formula includes the symbols of the elements in the compound and subscripts that indicate
a. the number of moles in each element.
b. how many atoms or ions of each type are combined in the simplest unit.
c. the formula mass.
d. the charges on the elements or ions.
____
6. How many atoms of fluorine are present in a molecule of carbon tetrafluoride, CF4?
a. 1
c. 4
b. 2
d. 5
____
7. Changing a subscript in a correctly written chemical formula
a. changes the number of moles represented by the formula.
b. changes the charges on the other ions in the compound.
c. changes the formula so that it no longer represents that compound.
d. has no effect on the formula.
________ 8. How many grams are there in 1.5 moles of chlorine gas?
a. 35.5 g
b. 71.0 g
c. 106.5 g
________ 9. The molar mass of MgI2 is _____.
a. the sum of the masses of 1 mol of Mg and 2 mol of I.
b. the sum of the masses of 1 mol of Mg and 1 mol of I.
d. 184.6 g
c. the sum of the masses of 2 mol of Mg and 2 mol of I.
d. impossible to calculate.
____ 10. The molar mass of NO2 is 46.01 g/mol. How many moles of NO2 are present in 114.95 g?
a. 0.4003 mol
c. 2.498 mol
b. 1.000 mol
d. 114.95 mol
____ 11. The molar mass of CCl4 is 153.81 g/mol. How many grams of CCl4 are needed to have 5.000 mol?
a. 5 g
c. 769.0 g
b. 30.76 g
d. 796.05 g
____ 12. The molar mass of H2O is 18.015 g/mol. How many grams of H2O are present in 0.20 mol?
a. 0.2 g
c. 35.9 g
b. 3.6 g
d. 89.9 g
______13. The empirical formula is always the accepted formula for a(n)
a. atom.
c. molecular compound.
b. molecule.
d. ionic compound.
____ 14. The empirical formula for a compound shows the symbols of the elements with subscripts indicating the
a. actual numbers of atoms in a molecule.
b. number of moles of the compound in 100 g.
c. smallest whole-number ratio of the atoms.
d. atomic masses of each element.
____ 15. The molecular formula for vitamin C is C6H8O6. What is the empirical formula?
a. CHO
c. C3H4O3
b. CH2O
d. C2H4O2
____ 16. A compound's empirical formula is C2H5. If the formula mass is 58 amu, what is the molecular formula?
a. C3H6
c. C5H8
b. C4H10
d. C5H15
____ 17. A compound's empirical formula is NO2. If the formula mass is 92 amu, what is the molecular formula?
a. NO
c. NO4
b. N2O2
d. N2O4
____ 18. The number of atoms in 1 mol of carbon is
a. 6.022 x 1022.
c. 5.022 x 1022.
b. 6.022 x 1023.
d. 5.022 x 1023.
____ 19. Molar mass
a. is the mass in grams of one mole of a substance.
b. is numerically equal to the average atomic mass of the element.
c. both a and b
d. neither a nor b
____ 20. A mass of 6.005 g of carbon (atomic mass 12.010 amu) contains
a. 1 mol C.
c. 0.5000 mol C.
b. 2 atoms C.
d. 1 atom O.
____ 21. What is the number of moles of chemical units represented by 9.03 x 1024 units?
a. 1.50 mol
c. 10.0 mol
b. 9.03 mol
d. 15.0 mol
____ 22. A prospector finds 39.39 g of gold (atomic mass 196.9665 amu). She has
a. 1.20 x1023 atoms.
c. 4.30 x 1023 atoms.
b. 2.30 x 1023 atoms.
d. 6.02 x 1023 atoms.
____ 23. A sample of tin (atomic mass 118.69 amu) contains 3.01 x 1023 atoms. The mass of the sample is
a. 3.01 g.
c. 72.6 g.
b. 59.3 g.
d. 11 g.
____ 24. What is the percentage composition of CF4?
a. 20% C, 80% F
c. 16.8% C, 83.2% F
b. 13.6% C, 86.4% F
d. 81% C, 19% F
____ 25. What is the percentage composition of CuCl2?
a. 33% Cu, 66% Cl
c. 65.50% Cu, 34.50% Cl
b. 50% Cu, 50% Cl
d. 47.263% Cu, 52.737% Cl
d. always equal to the total mass of the products.
Equations
____ 26. The law of conservation of mass follows from the concept that
a. atoms are indivisible in chemical reactions.
b. atoms of different elements have different properties.
c. matter is composed of atoms.
d. atoms can be destroyed in chemical reactions.
____ 27. According to the law of conservation of mass, when sodium, hydrogen, and oxygen react to form a
compound, the mass of the compound is ____ the sum of the masses of the individual elements.
a. equal to
c. less than
b. greater than
d. either greater than or less than
____ 28. Knowledge about what products are produced in a chemical reaction is obtained by
a. inspecting the chemical equation.
c. laboratory analysis.
b. balancing the chemical equation.
d. writing a word equation.
____ 29. A chemical reaction has NOT occurred if the products have
a. the same mass as the reactants.
b. less total bond energy than the reactants.
c. more total bond energy than the reactants.
d. the same chemical properties as the reactants.
____ 30. Which observation does NOT indicate that a chemical reaction has occurred?
a. formation of a precipitate
c. evolution of heat and light
b. production of a gas
d. change in total mass of substances
____ 31. A solid produced by a chemical reaction in solution that separates from the solution is called
a. a precipitate.
c. a molecule.
b. a reactant.
d. the mass of the product.
____ 32. After the correct formula for a reactant in an equation has been written, the
a. subscripts are adjusted to balance the equation.
b. formula should not be changed.
c. same formula must appear as the product.
d. symbols in the formula must not appear on the product side of the equation.
____ 33. In writing an equation that produces hydrogen gas, the correct representation of hydrogen gas is
a. H.
c. H2.
b. 2H.
d. OH.
____ 34. To balance a chemical equation, it may be necessary to adjust the
a. coefficients.
c. formulas of the products.
b. subscripts.
d. number of products.
____ 35. According to the law of conservation of mass, the total mass of the reacting substances is
a. always more than the total mass of the products.
b. always less than the total mass of the products.
c. sometimes more and sometimes less than the total mass of the products.
d. always equal to the total mass of the products.
____ 36. A chemical equation is balanced when the
a. coefficients of the reactants equal the coefficients of the products.
b. same number of each kind of atom appears in the reactants and in the products.
c. products and reactants are the same chemicals.
d. subscripts of the reactants equal the subscripts of the products.
____ 37.Which word equation represents the reaction that produces water from hydrogen and oxygen?
a. Water is produced from hydrogen and oxygen.
b. Hydrogen plus oxygen yields water.
c. H2 + O2 →water.
d. Water can be separated into hydrogen and oxygen.
____38. For the formula equation 2Mg + O2 → 2MgO, the word equation would begin
a. Manganese plus oxygen . . .
c. Magnesium plus oxygen . . .
b. Molybdenum plus oxygen . . .
d. Heat plus oxygen . . .
____39 . In an equation, the symbol for a substance in water solution is followed by
a. (1).
c. (aq).
b. (g).
d. (s).
____ 40. The reaction 2Mg(s) + O2(g) → 2MgO(s) is a
a. synthesis reaction.
c. single-replacement reaction.
b. decomposition reaction.
d. double-replacement reaction.
____ 41. The reaction Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq) is a
a. composition reaction.
c. single-replacement reaction.
b. decomposition reaction.
d. double-replacement reaction.
____ 42. In the equation 2Al(s) + 3Fe(NO3)2(aq) → 3Fe(s) + 2Al(NO3)3(aq), iron has been replaced by
a. nitrate.
c. aluminum.
b. water.
d. nitrogen.
____ 43. An insoluble gas that forms in a double-replacement reaction in aqueous solution
a. bubbles out of solution.
c. disassociates into ions.
b. forms a precipitate.
d. reacts with the water.
____ 44. The formulas for the products of the reaction between sodium hydroxide and sulfuric acid are ____.
a. Na2SO4 and H2O.
c. SI4 and Na2O.
b. NaSO4 and H2O.
d. S + O2 and Na.
____ 45. An element in the activity series can replace any element _____.
a. in the periodic table.
c. above it on the list.
b. below it on the list.
d. in its group.
____ 46. What can be predicted by using an activity series?
a. whether a certain chemical reaction will occur
b. the amount of energy released by a chemical reaction
c. the electronegativity values of elements
d. the melting points of elements
____ 47. According to the law of conservation of mass, when sodium, hydrogen, and oxygen react to form a
compound, the mass of the compound is ____ the sum of the masses of the individual elements.
a. equal to
c. less than
b. greater than
d. either greater than or less than
____ 48. A chemical equation is balanced when the
a. coefficients of the reactants equal the coefficients of the products.
b. same number of each kind of atom appears in the reactants and in the products.
c. products and reactants are the same chemicals.
d. subscripts of the reactants equal the subscripts of the products.
____ 49. Which word equation represents the reaction that produces water from hydrogen and oxygen?
a.
b.
c.
d.
Water is produced from hydrogen and oxygen.
Hydrogen plus oxygen yields water.
H2 + O2 → water.
Water can be separated into hydrogen and oxygen.
____50. For the formula equation 2Mg + O2 → 2MgO, the word equation would begin
a. Manganese plus oxygen . . .
c. Magnesium plus oxygen . . .
b. Molybdenum plus oxygen . . .
d. Heat plus oxygen . . .
____ 51 . In an equation, the symbol for a substance in water solution is followed by
a. (1).
c. (aq).
b. (g).
d. (s).
____ 52 . When the equation Fe3O4 + Al → Al2O3 + Fe is correctly balanced, what is the coefficient of Fe?
a. 3
c. 6
b. 4
d. 9
____53.Which coefficients correctly balance the formula equation NH4NO2(s) → N2(g) + H2O(l)?
a. 1, 2, 2
c. 2, 1, 1
b. 1, 1, 2
d. 2, 2, 2
____54.Which coefficients correctly balance the formula equation CaO + H2O → Ca(OH)2?
a. 2, 1, 2
c. 1, 2, 1
b. 1, 2, 3
d. 1, 1, 1
____ 55. The complete balanced equation for the reaction between zinc hydroxide and acetic acid is
a. ZnOH + CH3COOH → ZnCH3COO + H2O.
b. Zn(OH)2 + CH3COOH → Zn + 2CO2 +3H2O.
c. Zn(OH)2 + 2CH3COOH → Zn(CH3COO)2 + 2H2O.
d. Zn(OH)2 + 2CH3COOH → Zn(CH3COO)2 + H2 + O2.
____ 56. What is the balanced equation for the combustion of sulfur?
a. S(s) + O2(g) → SO(g)
c. 2S(s) + 3O2(g) → SO3(s)
b. S(s) + O2(g) → SO2(g)
d. S(s) + 2O2(g) → SO42–(aq)
____57 .Which equation is NOT balanced?
a. 2H2 + O2 → 2H2O
b. 4H2 + 2O2 → 4H2O
c. H2 + H2 + O2 → H2O + H2O
d. 2H2 + O2 → H2O
____ 58. The equation AX → A + X is the general equation for a
a. synthesis reaction.
c. combustion reaction.
b. decomposition reaction.
d. single-replacement reaction.
____ 59. The equation AX + BY → AY + BX is the general equation for a
a. synthesis reaction.
b. decomposition reaction.
c. single-replacement reaction.
d. double-replacement reaction.
____ 60. The equation A + X → AX is the general equation for a(n)
a. combustion reaction.
c. synthesis reaction.
b. ionic reaction.
d. double-replacement reaction.
____ 61. In what kind of reaction does a single compound produce two or more simpler substances?
a. decomposition reaction
c. single-replacement reaction
b. synthesis reaction
d. ionic reaction
____ 62. The equation A + BX → AX + B is the general equation for a
a. double-replacement reaction.
c. single-replacement reaction.
b. decomposition reaction.
d. combustion reaction.
____ 63. In what kind of reaction do the ions of two compounds exchange places in aqueous solution to form two
new compounds?
a. synthesis reaction
c. decomposition reaction
b. double-replacement reaction
d. combustion reaction
____ 64. The reaction 2Mg(s) + O2(g) → 2MgO(s) is a
a. synthesis reaction.
c. single-replacement reaction.
b. decomposition reaction.
d. double-replacement reaction.
____ 65. The reaction Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq) is a
a. composition reaction.
c. single-replacement reaction.
b. decomposition reaction.
d. double-replacement reaction.
____ 66. The formulas for the products of the reaction between sodium hydroxide and sulfuric acid are
a. Na2SO4 and H2O.
c. SI4 and Na2O.
b. NaSO4 and H2O.
d. S + O2 and Na.
Bonding and Molecular Geometry
____ 67. A mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the
atoms together is called a(n)
a. dipole.
c. chemical bond.
b. Lewis structure.
d. London force.
____68. Atoms are ____ when they are combined.
a. more stable
b. less stable
c. not bound together
d. at a high potential energy
____69.A chemical bond resulting from the electrostatic attraction between positive and negative ions is called a(n)
a. covalent bond.
c. charged bond.
b. ionic bond.
d. dipole bond.
____ 70.The chemical bond formed when two atoms share electrons is called a(n)
a. ionic bond.
c. Lewis structure.
b. orbital bond.
d. covalent bond.
____71.
If two covalently bonded atoms are identical, the bond is
a. nonpolar covalent.
c. nonionic.
b. polar covalent.
d. coordinate covalent.
____72.
If the atoms that share electrons have an unequal attraction for the electrons, the bond is called
a. nonpolar.
c. ionic.
b. polar.
d. dipolar.
____73.The B—F bond in BF3 (electronegativity for B is 2.0; electronegativity for F is 4.0) is
a. polar covalent.
c. nonpolar covalent.
b. ionic.
d. pure covalent.
____74. In which of these compounds is the bond between the atoms NOT a nonpolar covalent bond?
a. Cl2
c. HCl
b. H2
d. O2
____ 75. A molecule is a
a. negatively charged group of atoms held together by covalent bonds.
b. positively charged group of atoms held together by covalent bonds.
c. neutral group of atoms held together by covalent bonds.
d. neutral group of atoms held together by ionic bonds.
____ 76. What principle states that atoms tend to form compounds so that each atom can have eight electrons in
its outermost energy level?
a. rule of eights
c. configuration rule
b. Avogadro principle
d. octet rule
____ 77. Multiple covalent bonds may occur in atoms that contain carbon, nitrogen, or
a. chlorine.
c. oxygen.
b. hydrogen.
d. helium.
____ 78.
A shorthand representation of the composition of a substance using atomic symbols and numerical
subscripts is called a(n)
a. Lewis structure.
c. polyatomic ion.
b. chemical formula.
d. multiple bond.
____ 79. The ions in an ionic compound are organized into a(n)
a. molecule.
c. polyatomic ion.
b. Lewis structure.
d. crystal.
____ 80. In a crystal of an ionic compound, each cation is surrounded by
a. molecules.
b. positive ions.
c. dipoles.
d. anions.
____ 81. To form a molecule with a “bent” shape, the ratio of shared to unshared pairs of electrons is __.
a. 1:2
c. 2:2
b. 2:1
d. 3:1
____ 82. Which molecule has a pyramidal shape?
a. CBr4
b. CO2
c. BF3
d. NH3
____ 83. Identify the molecule that will have a linear shape.
a. CCl4
b. H2O
c. NH3
d. CO2
____ 84. Which formula represents a tetrahedral molecule?
a. SiBr4
c. HBr
b. CaCl2
d. AlF3
____ 85
The correct electron dot notation for a molecule of iodine is
____ 86. VSEPR theory is a model for predicting _____.
a. the strength of metallic bonds.
c. lattice energy values.
b. the shape of molecules.
d. ionization energy.
____ 87. Which bond has the greatest degree of ionic bonding?
a) Li-Br
b) F-F
c) H-Cl
d) S-O
____ 88. If two atoms exert equal attractions for electrons, they form ____.
a) a non-polar covalent bond;
b) an ionic bond;
c) a polar covalent bond;
____ 89. Which of the following is not a polar molecule?
a) hydrogen fluoride
b) hydrogen
c) water
____ 90. Which of the following kinds of bonds exists in a N2 molecule?
a) ionic
b) polar
c) single
d) double
d) ammonia (NH3)
e) triple
____ 91. A polar molecule is one in which there is a separation of charge caused by
a) an average distribution of electrons;
b) a non-uniform electron distribution;
c) a complete loss of electrons;
d) an uneven number of electron pairs.
____ 92. Which is an example of a non-polar molecule that contains polar covalent bonds?
a) CBr4
b) N2
c) H2O
d) NH3
e) none of these
d) no bond
_____93. Which one is an example of a diatomic molecule?
a) magnesium ion
b) nitrogen gas
c) helium gas
d) sodium chloride
_____94. Why is NH3 classified as a polar molecule?
a) It is a gas at STP.
b) N-H bonds are non-polar.
c) Nitrogen and hydrogen
are both nonmetals.
d) NH3 molecules have asymmetrical charge distributions.
_____95. The substance whose electron dot formula indicates four covalent bonds is
a) AlF3;
b) N2;
c) H2O;
d) CH2F2.
_____96. The molecular shape predicted by the VSEPR theory when two shared pairs of electrons and no
unshared pair of electrons surround the central atom is
a) tetrahedral;
b) pyramidal;
c) bent;
d) linear.
_____97. Which pair of elements will not form an ionic bond?
a) Ba and Cl
b) Ca and S
c) K and O
d) C and Cl
_____98.What is the true electron dot notation for ammonia, NH3?
SIGNIFICANT FIGURES, MEASUREMENTS AND DIMENSIONAL ANALYSIS
_____99. For the mathematical operation: 23.456cm + 15.34cm + 12.10cm. What is the proper answer taking into account
of significant figures?
a) 51cm
b) 50.9cm
c) 50.90cm
d) 50.896cm
_____100. How many significant figures are there in 3.25900 cm?
a. 2
b. 4
c. 3
e) none of these.
d. 5
e. 6
_____101. What is the correct answer for the following operation taking into account of significant figures:
2.657m x 1.64m x 0.67 m = ?
a) 2.9m3
b) 2.92m3
c) 2.920m3
d) 2.9195m3
e) None of these.
_____102. Round the following measurement to 3 significant figures: 321500 cm.
a) 312cm
b) 32150cm
c) 322000cm
d) 321000cm
_____103. Fill in the blank. 2.56 x 10-3 m = _____ x 10-5m
a) 0.0256
b) 2.56
c) 25.6
d) 256
_____104. Fill in the blanks. 6.82 x 104kg = ___________ x 106kg
a) 0.0682
b) 0.682
c) 68.2
d) 682
e) None.
e) none of these
e) none of these
_____105. How many significant figures are there in the measurement of 321000 s?
a) 6
b) 5
c) 3
d) 2
e) 1
_____106. How many mg are there in 2.34 x 10-2Mg? (M: 106; m: 10-3)
a) 2.34 x 10-2
b) 2.34 x 103
c) 2.34 x 105
d) 2.34 x 107
e) None of these.
_____107. For the view below of a graduated cylinder filled with liquid, what is the correct reading on the vol-
ume of liquid?
a) 46.7mL
b) 42.9mL
c) 45.3mL
d) 43.6mL
_____108. How many pounds are there in 345.3 grams? (1pound = 16oz; 1oz = 28.35g)
a) 12.18
b) 0.7612
c) 156600
d) 21.58
e) None of these.
_____109. Round the following measurement to 3 significant figures and then turn it into scientific notation.
92356700 m. The correct answer is ___________.
a) 92.4 x 106
b) 0.924 x 108
c) 9.24 x 107
d) 9.24 x 106
e) none of these
STOICHIOMETRY
_____110. For the chemical reaction: 4NH3(g) + 5O2(g) --> 6H2O(g) + 4NO(g). How many moles of oxygen gas
will be needed when 12 moles of NH3 is completely reacted?
a) 5
b) 10
c) 15
d) 20
e) None of these.
_____111. When 8 grams of hydrogen are chemically combined with oxygen to form water, the amount of
oxygen needed is ____. [2H2(g) + O2(g) --> 2H2O(g)]
a) 1g
b) 16g
c) 32g
d) 64g
e) 128g
_____112. Given the reaction CH4 + 2O2 --> CO2 + 2H2O, what amount of oxygen is needed to completely react
with 1 mole of CH4?
a) 2 moles
b) 2 atoms
c) 2 grams
d) 2 molecules e) None of these.
_____113. A balanced chemical equation allows one to determine the _____.
a) mole ratio of any two substances in the reaction
b) energy released in the reaction
c) electron configuration of all elements in the reaction
d) mechanism involved in the reaction
_____114. In the reaction 2Al2O3 --> 4Al + 3O2, what is the mole ratio of aluminum to oxygen?
a) 10:6
b) 3:4
c) 2:3
d) 4:3
_____115. What is the small whole number that appears in front of a formula in a chemical equation?
a) a subscript
b) a superscript
c) a ratio
d) a coefficient
e) none of these.
_____116. For the reaction 2Na + 2H2O --> 2NaOH + H2, how many grams of sodium hydroxide are produced
from 3.0 mol. of water?
a) 40. g
b) 80. g
c) 120 g
d) 240 g
_____117. Calculate the number of moles of Al2O3 that are produced when 0.60 mol of Fe is produced in the
following reaction: 2Al(s) + 3FeO(s) --> 3Fe(s) + Al2O3(s)
a) 0.20 mol.
b) 0.40 mol.
c) 0.60 mol.
d) 0.90 mol.
_____118. Hydrogen gas reacts with oxygen gas to produce water vapor. Balanced chemical equation is: 2H2(g) + O2(g)
 2H2O(g). How many moles of hydrogen gas will be consumed for the production of 3.64 moles of water?
a) 7.28 mol.
b) 3.64 mol.
c) 1.82 mol.
d) 0.91 mol.
_____119. For the incomplete combustion of ethane (C2H6), what is the mole ratio between ethane and oxygen
gas? [Hint: write skeleton equation of the incomplete combustion reaction, balance it, carry out proper
calculations.]
a) 1:2
b) 2:1
c) 5:2
d) 2:5
e) 1:3
Answers
1
2
3
4
5
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7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
C
D
A
A
B
C
C
C
A
C
C
B
C
C
C
B
D
B
C
C
D
A
B
B
D
A
A
C
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
A
B
A
A
B
B
C
C
D
B
D
C
B
D
B
D
C
A
C
B
A
C
A
C
A
B
D
A
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
A
A
B
E
B
A
B
D
D
D
D
2
C
E
A
C
D
A
C
D
B
B
C
C
D
A
A
D
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
D
D
A
B
C
A
D
B
B
C
C
A
C
C
A
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
B
B
C
C
D
C
B
D
D
C
D
D
A
3
B
115
116
117
118
119
D
C
A
B
D