Practice Test for Exam 111 A
1. When an electric discharge is passed through boron trichloride, a new compound is formed. What is its
simplest formula, if on analysis it is shown to contain 0.0878 g of chlorine and 0.0131 g of boron?
Atomic Molar Masses
10.8 g·mol–1
35.5 g·mol–1
B
Cl
(A)
BCl
(B)
BCl2
(C)
BCl3
(D)
B2Cl3
2. An amino acid has a molar mass of 776.9 g·mol–1 and contains 65.34% iodine by mass. What is the
number of iodine atoms per molecule of amino acid?
(A)
one
(B)
three
(C)
four
(D)
five
3. If a 17.0 g sample of impure nickel metal reacts under STP conditions(1.00 atm pressure and 0.00oC)
with 25.0 L of CO gas to form 0.25 L of Ni(CO)4 gas, what is the percentage of Ni in the metal
sample?
Ni(s) + 4CO(g) → Ni(CO)4(g)
Molar Masses
Ni
58.7 g·mol–1
Ni(CO)4 171. g·mol–1
(A)
24.1%
(B)
25.0%
(C) 96.4%
(D) 100%
4. A piece of silver foil having a mass of 0.5840 g had become tarnished because of formation of Ag2S,
with a mass increase of 0.0010 g. What percentage of the original silver has been converted to Ag2S?
Atomic Molar Masses
32. g·mol–1
108. g·mol–1
S
Ag
(A)
0.6%
(B)
1.2%
(C)
1.8%
(D)
2.4%
5. A 2.00 g mixture of NaCl and NaNO3 dissolved in water required 90 mL of 0.10 M AgNO3 to
precipitate all the chloride. What is the mass percentage of NaCl in the original sample?
a. First, write the equation for the formation of the precipitate that will form when silver ions from the
silver nitrate react with the chloride ions of the sodium chloride:
____________________________________
b. What is the mass percentage of NaCl in the original sample?
Atomic Molar Masses
(A)
Na
Ag
Cl
N
O
10
23.0 g·mol–1
107.9 g·mol–1
35.5 g·mol–1
14.0 g·mol–1
16.0 g·mol–1
(B)
26
(C)
58
(D)
90
6. The formula for methane is CH4. This means that, in methane,
Atomic Molar Masses
(A)
(B)
(C)
(D)
(E)
C
12.0 g·mol–1
H
1.0 g·mol–1
for every 100 atoms of hydrogen there are 400 atoms of carbon.
for every atom of carbon there are four grams of hydrogen.
for every gram of hydrogen there are twelve grams of carbon.
the compound is 25% hydrogen by mass.
the compound is 80% hydrogen by mass.
7. How many moles of Fe are needed to produce 10.0 mol of H2?
4 H2O(g) + 3 Fe(s) → Fe3O4(s) + 4 H2(g)
(A)
(B)
7.50 mol
13.3 mol
(C)
(D)
15.0 mol
30.0 mol
8. Assuming complete oxidation in the reaction
C(s) + O2(g) → CO2(g)
what mass of CO2 will 15 g of carbon produce?
Molar Masses
g·mol–1
C
O2
CO2
(A) 11 g
12.
32. g·mol–1
44. g·mol–1
(B) 22 g
(C) 44 g
(D) 55 g
9. Sulfur dioxide, SO2, can be produced from sulfur and oxygen.
a. First: Write and balance the equation for: Sulfur(s) + Oxygen gas -Æ Sulfur Dioxide
_______________________________________________________
b. How many moles of sulfur dioxide, SO2, can be produced from 160 g of sulfur and 320 g of
oxygen?
Atomic Molar Masses
32. g·mol–1
16. g·mol–1
S
O
(A) 2.5 mol
(B) 5.0 mol
(C 7.5 mol
(D) 10.0 mol
10. A reaction between Na2O and P4O10 forms the one product, Na3PO4
a. Write and balance the equation described above:
b.
How many grams of Na3PO4 will be produced from the reaction of 0.200 mol of Na2O with excess
P4O10?
Molar Masses
Na3PO4
Na2O
P4O10
(A) 21.9 g
164. g·mol–1
62. g·mol–1
284. g·mol–1
(B) 32.8 g
(C) 43.8 g
(D) 131 g
11. If 10 mL of 6.0 M NaOH neutralizes 30 mL of hydrochloric acid, what is the molarity of the acid?
(A) 1.0 M
(B) 2.0 M
(C) 3.0 M
(D) 0.20 M
12. In the reaction: 3 Ca(OH)2(s) + 2 H3PO4(aq) → Ca3(PO4)2(s) + 6 H2O(l)
how many grams of Ca(OH)2 are required to neutralize 10 L of 0.60 M H3PO4 solution?
Molar Masses
Ca(OH)2
H3PO4
(A) 300 g
g·mol–1
74.
94. g·mol–1
(B) 330 g
(C) 390 g
(D) 670 g
13. What mass of CaCO3 will produce 8.0 L of CO2 measured at STP conditions (which are 1 atmosphere
and 0 oC) in this reaction.
CaCO3(s) → CaO(s) + CO2(g) ?
Molar Mass
CaCO3
100.
g·mol–1
(A) 4.5 g
(C)
12.5 g
(B) 36 g
(D)
280 g
14. What is the maximum mass of CO2 which can be produced by the reaction between one mole of CH4
and one mole of O2? Assume the reaction to be
CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
Molar Masses
CH4
O2
CO2
H2O
(A) 11 g
16. g·mol–1
32. g·mol–1
44. g·mol–1
18. g·mol–1
(B) 22 g
(C) 33 g
(D) 44 g
15. Assume that the reaction between hydrogen and oxygen goes to completion. Which statement is true if
10.0 g of hydrogen is mixed with 64.0 g of oxygen and ignited?
Atomic Molar Masses
H
1.01 g·mol–1
O
16.0 g·mol–1
a. First: Write and balance the equation for hydrogen gas plus oxygen gas yields water.
_______________________________________________
b. Which statement is true, if 10.0 g of hydrogen is mixed with 64.0 g of oxygen and ignited?
(A). The limiting reagent is oxygen.
(B). 74 g of water will form.
(C). 3 mol of hydrogen will be left over after the reaction.
(D). 68 g of water will form.
16. What mass of MgCl2 is required to prepare 2.00 L of 0.550 M solution?
Molar Mass
MgCl2
(A) 1.10 g
g·mol–1
95.2
(B) 28.9 g
(C) 86.5 g
(D) 105 g
17. To what volume in liters must 105 mL of hydrochloric acid, containing 47.5 g of HCl, be diluted to
make a 1.05 M solution?
Atomic Molar Masses
1.0 g·mol–1
35.5 g·mol–1
H
Cl
(A) 1.24 L
(B) 1.30 L
(C) 2.00 L
(D) 3.40 L
18. A 1.20 L sample is drawn from a bottle labeled “86.0% by weight H2SO4, density 1.787 g·mL–1”.
What is the molarity of the sample?
Molar Mass
H2SO4
(A) 8.78 M
g·mol–1
98.1
(B) 10.5 M
(C) 5.7 M
(D) 18.2 M
19. The number of neutrons in the nucleus of a specific atom is equal to its
(A)
atomic mass.
(B)
mass number.
(C)
atomic number.
(D)
mass number minus the atomic number.
20. The species designated as
(A) Fe
56
24X is
(B) Ge
(C) Ba
(D) Cr
21. What do these have in common?
20Ne
(A)
(B)
(C)
(D)
19F–
the same number of protons
the same number of neutrons
the same number of electrons
the same size
22. The stable isotope of fluorine is
(A) l+
24Mg2+
(B) 7+
19
–
9 F. The charge on the nucleus of the fluoride ion, F , is
(C) 9+
(D) l–
23. An atom of strontium–90: (
(A)
(B)
(C)
(D)
90
38Sr ) contains
38 electrons, 38 protons, 52 neutrons.
38 electrons, 38 protons, 90 neutrons.
52 electrons, 52 protons, 38 neutrons.
52 electrons, 38 protons, 38 neutrons.
24. What happens when an atom of a metal becomes a cation?
(A)
(B)
(C)
(D)
The metal atom gains electrons.
The metal atom is oxidized.
The ionic radius becomes greater than the atomic radius.
The metal atom serves as an oxidizing agent.
25. The 2p orbitals are often represented as being
(A)
elliptical.
(D)
(B)
pyramidal.
(E)
(C)
dumbbell shaped.
tetrahedral.
spherical.
26. When alpha particles were shot at a gold foil target, most of the particles were undeflected. This
indicated to Rutherford that
(A)
the gold foil was continuous matter.
(B)
the mass of the gold atoms was spread out thinly.
(C)
the atoms of gold were mostly empty space.
(D)
the alpha particles had great penetrating power.
(E)
the alpha particles had charges opposite to those on the nuclei.
27. A sodium ion differs from a sodium atom in that the sodium ion
(A)
is more reactive.
(B)
has fewer electrons.
(C)
is an isotope of sodium.
(D)
exists only in solution.
(E)
has a negative charge on its nucleus.
28. What is the number of unpaired electrons in an isolated free iron atom (atomic number 26) in the
ground state?
(A) zero
(B) two
(C) three
(D) four
29. An atom has a valence shell electron configuration of ns1. To which group of elements in the periodic
table does it belong?
(A)
transition metals
(C)
alkaline earth metals
(B)
rare earth metals
(D)
alkali metals
30. How much of each reactant remains after 54 g of aluminum and 32 g of oxygen undergo the reaction
4 Al(s) + 3 O2(g) → 2 Al2O3(s)
Atomic Molar Masses
Al
O
27 g·mol–1
16 g·mol–1
(A)
no Al, no O2
(C)
no Al, 8.0 g O2
(B)
18 g Al, no O2
(D)
6.0 g Al, no O2
31. Beginning with 84.0 g CaH2 and 18.0 g H2O, how many liters of H2 at STP(1 atm and 0oC) can be
produced in this reaction?
CaH2(s) + 2 H2O(l) → 2 H2(g) + Ca(OH)2(s)
Molar Masses
g·mol–1
CaH2
H2O
(A) 11.2 L
42.0
18.0 g·mol–1
(B) 22.4 L
(C) 44.8 L
(D) 89.6 L
32. The ground–state electronic configuration of the manganese (Mn) atom is
33.
(A)
(B)
1s22s22p63s23p64s2 4d5
1s22s22p63s23p63d7
(C)
1s22s22p63s23p64s24p5
(D)
1s22s22p63s23p64s23d5
1
2
3
The species 1H, 1H, and 1H represent three
(A) allotropes. (B) homologs. (C) isomers.
(D) isotopes.
34. Emission spectra (line spectra) may be attributed to an electron
(A)
spiraling into a nucleus.
(B)
changing its atomic energy level.
(C)
reversing its direction of spin.
(D)
escaping from the atom.
35. Which electron transition is associated with the largest emission of energy?
(A)
n = 2 to n = 1
(C)
n = 2 to n = 4
(B)
n = 2 to n = 3
(D)
n = 3 to n = 2
36. The energy of a photon is greatest in the case of
(A)
X–radiation.
(C)
visible light.
(B)
ultraviolet radiation.
(D)
infrared radiation
37. Which set of quantum numbers is possible for an electron in an atom?
(C)
n = 3, l = 0, ml = 1 , ms = – 1/2
n = 2, l = 2, ml = –2 , ms = – 1/2
n = 5, l = 2, ml = 2 , ms = +1/2
(E)
n = 4, l = 3, ml = –4 , ms = – ½
(A)
(B)
38. In which compound does ionic bonding predominate?
(A)
LiBr
(B)
CO
(C)
H2O
(D)
SiC
39. Which best represents hydrogen bonding in liquid methanol (CH3OH)?
(A)
(B)
H
O
H
H
O
C
H
H
C
H
H
H
H
O
O
H
H
C
C
H
H
H
H
H
H
(C)
H
H
H
H
C
C
O
H
O
H
H
(D)
H
H
H
C
O
H
H
C
O
H
H
H
40. When 30.0 g of CH4 reacts completely with excess chlorine yielding 52.0 g of HCl, what is the
percentage yield?
CH4(g) + Cl2(g) → CH3Cl(g) + HCl(g)
Molar Masses
g·mol–1
CH4
HCl
(A)
24.0%
16.0
36.5 g·mol–1
(B)
25.2%
(C)
42.3%
(D)
76.0%
41. Which phenomenon can be explained by assuming strong hydrogen bonding?
(A)
(B)
(C)
(D)
H2 reacts with Cl2 to form HCl.
The boiling point of water is higher than that of H2S.
The boiling point of C7H16 is higher than that of C3H8.
The boiling point of H2Se is higher than that of H2S.
42. Which compound contains the longest carbon-to-nitrogen bond?
(A) H
H
H
C
N
H
(C) H
C
H
C
C
N
H
H
(B) H
H
N
(D)
All are equal.
H
43. According to modern bonding theory the number of sigma (σ) and pi (π) bonds in the ethylene
molecule H2C=CH2 is
(A)
1 σ and 4 π
(D)
1 π and 5 σ
(B)
1 σ and 5 π
(E)
2 π and 4 σ
(C)
1 π and 4 σ
44. Which molecule contains one unshared pair of valence electrons?
(A)
H2O
(B)
NH3
(C)
CH4
(D) C2H4
45. Which has a Lewis (electron dot) structure with the greatest number of unshared pairs on the central
atom?
(A) NH3
(B) IF3
(C) SeCl2
(D) ICl2
46. Which molecule contains only two unshared pairs of electrons?
(A)
H2O
(B)
NH3
(C)
BeCl2 (D)
MgO
47. Which is the correct formula/name combination?
(A)
(B)
(C)
(D)
Al2(SO4)3 / aluminum sulfate.
K2PO3 / potassium phosphate.
C2H3O– / acetate ion.
PCl3 / phosphorus chlorite.
48. The correct IUPAC name of N2O3 is
(A)
(B)
nitrogen oxide. (C)
nitrous oxide. (D)
nitrogen(II) oxide.
dinitrogen trioxide.
49. In which case is the substance with the given formula followed by its correct name?
(A)
(B)
(C)
(D)
(E)
KNO2 – potassium nitrate
FeCl3 – iron(III) chloride
FeS – iron(II) sulfite
Mg3N2 – magnesium nitrite
HClO – hydrochloric oxide
50. How many moles of Al2O3 can be produced from 27 g of aluminum and 16 g of oxygen?
Atomic Molar Masses
27.0 g·mol–1
16.0 g·mol–1
Al
O
(A) 0.67
(B) 0.50
(C) 0.33
(D) 0.17
51. Balance the equation
? N2H4 + ? N2O4 → ? N2 + ? H2O
How many moles of N2 will be produced for every mole of N2O4 that reacts?
(A)
one
(B)
two
(C)
three
(D)
four
52. Complete and balance the equation for the reaction, where the reactants are in aqueous solution. Use no
fractional coefficients.
? Na3PO4 + ? Ba(NO3)2 → ? + ?
The number of moles and formula of the product containing Ba are
(A) 3BaNO3
(B) BaPO4
(C) Ba(PO4)2
(D) Ba2P3
(E) Ba3(PO4)2
53. Substances that contain water incorporated in the crystal in definite proportions by weight are
(A)
(B)
(C)
anhydrous.
amorphous.
hydrates.
(D)
(E)
polymorphous.
zeolites.
54. According to the kinetic–molecular theory,
(A)
gaseous molecules are continuously in random motion and collisions are perfectly elastic.
(B)
the absolute temperature of a gas depends on its molar mass.
(C)
the pressure exerted on a gas affects the speed of its molecules.
(D)
gaseous molecules can travel in straight or curved paths.
(F)
all gaseous molecules are diatomic.
55. Compressing a fixed quantity of gas while keeping its temperature constant produces a higher pressure,
because
(A)
there are more molecules per unit volume after compression.
(B)
there are fewer molecules per unit volume after compression.
(C)
the elasticity of the molecules increases.
(D)
the molecules move faster.
(F)
each molecule hits the container wall harder.
56. If oxygen gas and hydrogen gas are kept at the same temperature and pressure, the hydrogen molecules
on the average
(A)
move faster than the oxygen molecules.
(B)
move more slowly than the oxygen molecules.
(C)
move at the same speed as the oxygen molecules.
(D)
have the greater kinetic energy.
(E)
have a lower kinetic energy.
57. A 10.0 cm3 container of helium is sealed at 22.0 °C and 1.00 atm pressure. What pressure would be
exerted by the helium if the container were heated to 220 °C?
(A) 10.0 atm
(B) 2.01 atm
(C) 1.67 atm
(D) 1.08 atm
58. If 6.60 g of a gaseous compound occupy a volume of 1.20 L at 27 °C and 0.967 atm, the molar mass of
the compound is
(A) 109 g·mol–1
(B) 123 g·mol–1
(C) 140 g·mol–1
59. Real gases are most like ideal gases at
(A)
high pressure and high temperature.
(B)
low pressure and low temperature.
(C)
high pressure and low temperature.
(D)
low pressure and high temperature.
(D) 165 g·mol–1
60. Given a mixture of gases: 1.00 g He, 14.0 g N2 and 10.0 g NO. What is the total pressure at 27.0 °C if
the gases are confined in a 2.00 L container?
Molar Masses
4.00 g·mol–1
28.0 g·mol–1
30.0 g·mol–1
He
N2
NO
(A) 0.310 atm
(B) 1.24 atm
(C) 13.3 atm
(D) 21.6 atm
61. Which assumption of Dalton’s atomic theory had to be revised or discarded because of the discovery of
radioactivity?
Dalton’s Original Atomic Theory
1. The ultimate particles of matter are the atoms of elements, which are indivisible and
indestructible.
2. All the atoms of a given element are alike in all respects.
3. The atoms of different elements differ in one or more properties.
4. Compounds are formed by combination of different kinds of atoms.
(A)
l
(B)
2
(C)
3
(D)
4
62. Which is correct for most metals?
(A)
form complex ions
(B)
have variable valence
(C)
have colored ions
(D)
are amphoteric
(F)
give up electrons to chlorine
63. The heat capacity of benzene is 81.7 J·mol–1·°C–1. How much heat (in joules) is required to raise the
temperature of 39.0 g of benzene by 10.0 °C?
Molar Mass
benzene
(A)
41.9 J
(B)
78.0 g·mol–1
409 J
(C)
816 J
(D)
1630 J
64. Which produces the greatest number of ions when one mole dissolves in water?
(B) NH4Cl
(A) NaCl
(C) NH4NO3
(D) Na2SO4
65. How many moles of NH3 can be formed when 0.50 mol of NCl3 is allowed to react with 0.40 mol of
2 NCl3 + 3 H2 → 2 NH3 + 3 Cl2
H2?
(A) 0.27 mol
(B) 0.50 mol
(C) 0.60 mol
66. Which substance has the highest boiling point?
(A)
CH4
(B)
He
(C)
HF
(D)
Cl2
(D) 0.90 mol
67. In the phase diagram, which transition represents the condensation of a gas to a liquid?
A
B
P
C
D
T
(A) B to A
(B) D to B
(C) C to D
(D) A to D
68. A particular compound has a crystal lattice with a cubic unit cell with atoms A in the corner positions
and atoms B in the body–centered position. The simplest formula for the compound is
(A)
A4B
(B)
A2B
(C)
AB
(D)
A8B
69. Carbon dioxide, CO2, in the form of dry ice would be classified as
(A) an ionic solid.
(B) a polymeric solid
(C) a molecular solid.
(D) a metallic solid.
70. A crystal of anhydrous KNO3 is made up of
(A)
molecules of KNO3.
(B)
atoms of potassium, nitrogen, and 3 atoms of oxygen alternately spaced in the crystal.
(C)
a geometrical pattern of potassium ions and nitrate ions in the crystal.
(D)
potassium nitrate molecules alternately spaced with water molecules.
(E)
molecules of KNO3 and water combined into larger molecules.
71. The stronger the intermolecular forces in a substance
(A)
the higher the boiling point.
(B)
the lower the boiling point.
(C)
the higher the vapor pressure.
(D)
the smaller the deviation from ideal gas behavior.
72. The vapor pressure of four different substances at 20 °C is given in the table.
Substance
Vapor Pressure (in mmHg)
A
0.0012
B
18
C
175
D
442
Which statement is correct?
(A)
The normal boiling point of D should be greater than that of B.
(B)
The heat of vaporization of C should be greater than that of B.
(C)
The intermolecular forces between B molecules should be greater than those between A
molecules.
(D)
The surface tension of B should be greater than that of C.
73. Which group of substances is correctly arranged in order from the highest to the lowest melting point?
(A)
HF>H2>NaF
(C)
NaF>H2>HF
(D)
NaF>HF>H2
(B)
HF>NaF>H2
74. Arrange KCl, NH3, and CH4 in order of increasing boiling point.
(A)
CH4<KCl<NH3
(C) NH3<KCl<CH4
(D) NH3<CH4<KCl
(B)
CH4<NH3<KCl
75. The shape that most closely describes the shape of the NF3 molecule is
(A)
octahedral.
(C)
trigonal pyramidal.
(B)
trigonal planar.
(D)
tetrahedral.
76. Which geometry is associated with an sp hybridized atom?
(A)
pyramidal
(C)
trigonal planar
(B)
tetrahedral
(D)
linear
77. The Lewis structure of BrF5 is
:F:
:F
Br
F:
:F :
:F:
a. The geometry around the central atom for BrF5 is:
(A)
square pyramidal.
(C)
(B)
trigonal bipyramidal.
(D)
b.
The molecular shape/structure of BrF5 is:
(A)
square pyramidal.
(B)
trigonal bipyramidal.
78. Which is planar?
(A) PCl3
(B) ClO3–
(C) CO32–
(C)
(D)
trigonal pyramidal.
octahedral.
trigonal pyramidal.
octahedral.
(D) NH3
(E) PH3
79. For which molecule can the bonding be described in terms of sp3 hybrid orbitals of the central atom?
(A)
SF6
(B)
BF3
(C)
PCl5
(D)
NH3
:
80. The molecule O C N H has been detected in gas clouds between stars.
The predicted C—N—H bond angle is about
(A)
60°
(B)
90°
(C)
109°
(D)
120°