CHEM 1120 Practice Final Exam
CHEM 1120 – Practice Final Exam
*Note* This exam is presented as a diagnostic tool to aid in your preparation for the examination. It is
recommended that you treat this practice exam like the actual exam: set aside one hour to take the exam with no
more than a calculator, periodic table, and equation sheet provided on iLearn. Be advised that success on this
practice exam in no way guarantees success on the actual examination.
Multiple Choice
Identify the choice that best completes the statement or answers the question.
1. The acceleration due to gravity on the surface of Uranus 8.83 m/s2. What is this expressed in km/min2?
a. 0.530
b. 2.45
c. 31.8
d. 147
2. What is the answer to the following calculation, expressed to the proper number of significant figures?
(12.345 - 6.789)
10.1112
a. 0.55
b.
0.549
3. In all neutral atoms, there are equal numbers of…
a. …protons and neutrons.
b. …positrons and electrons.
c.
0.5495
d.
c.
d.
…neutrons and electrons.
…electrons and protons.
0.54949
4. Which statement concerning the structure of the atom is correct?
a. Protons and neutrons have most of the mass, and occupy most of the volume of the atom.
b. Protons and neutrons have most of the mass, but occupy very little of the volume of the atom.
c. Electrons have most of the mass, and occupy most of the volume of the atom.
d. Electrons have most of the mass, but occupy very little of the volume of the atom.
5. The number of neutrons in the 35
17Cl ion is:
a. 17
b. 18
c.
6. Which pair of particles has the same number of electrons?
a. F-, Mg2+
b. Ne, Ar
c.
20
d.
21
Br-, Se
d.
Al3+, P3-
7. The element X occurs naturally to the extent of 20.0% 12X and 80.0% 13X. What is the atomic mass of element X
in amu?
a. 12.2
b. 12.4
c. 12.8
d. 13.0
8. How many atoms are in 1.50 g of Al?
a. 0.0556
b. 18.0
c.
3.35x1022
9. Which of the following electron configurations is impossible?
a. 1s22s22p63s2
b. 1s22s22p63s23p6
c. 1s22s22p62d2
10. The ground-state electron configuration for the manganese atom is:
a. 1s22s22p63s23p64s24d5 b. 1s22s22p63s23p64s24p5 c. 1s22s22p63s23p63d7
d.
2.44x1025
d.
1s22s22p53s1
d. 1s22s22p63s23p64s23d5
1
CHEM 1120 Practice Final Exam
11. Which species has the ground state electron configuration 1s22s22p63s23p63d10?
a. Ni
b. Ni2+
c. Zn
d.
Zn2+
12. Which of the following incorrectly ranks the species in order of the indicated property?
a. Radius: Sr > Ca > Ge > Si
c. Electronegativity: F > Cl > Na > K
b. Ionization Energy: O > P > S > As
d. Radius: Sr2+ > Rb+ > Br- > Se213. An unknown compound is analyzed and it is found that 4.67x1016 molecules of the compound has a mass of
3.41x10-6 g. Which of the following could be the unknown compound?
a. CO2
b. CH4
c. NH3
d. H2O
14. What is the percent by mass of sodium in sodium borate, Na3BO3?
a. 46.2
b. 49.8
c. 54.0
d.
69.0
15. A 4.08 g sample of a compound of nitrogen and oxygen contains 3.02 g of oxygen. What is the empirical formula
of the compound?
a. NO
b. NO2
c. N2O
d. N2O5
16. How many valence electrons are present in the Lewis electron-dot structure for SO32-?
a. 6
b. 22
c. 24
d.
26
17. Resonance structures describe molecules that have:
a. hybrid orbitals
b. delocalized electrons
c.
rapid equilibria
d.
multiple isomers
18. What is the electron domain geometry (EDG) around the central atom in XeF4?
a. trigonal pyramidal
b. tetrahedral
c. see-saw
d.
octahedral
19. NH3 reacts with BF3 to form the Lewis acid-base adduct H3NBF3. What is the geometry around the nitrogen and
boron atoms in the adduct?
a. Both atoms are tetrahedral.
b. Nitrogen is tetrahedral; boron is linear.
c. Nitrogen is pyramidal; boron is planar.
d. Nitrogen is planar; boron is pyramidal.
20. Which of the following bond angles will be the largest?
a. The O-S-O angle in SO42b. The F-Be-F angle in BeF2
c.
d.
The Cl-C-Cl angle in HCCl3
The H-O-H angle in H2O
21. Which type of hybrid orbitals are present in CO2?
a. sp
b. sp2
c.
sp3
d.
sp3d
22. Which of the following is a molecular substance that, when pure, exhibits dipole-dipole interactions?
a. TiF4
b. CF4
c. SF4
d. XeF4
2
CHEM 1120 Practice Final Exam
23. The boiling point of H2O, compared with the other members of the series, can be explained by:
Boiling Points of Group 16 (VIA) Hydrides
H2O
H2S
H2Se
Compound
99.974
-59.55
-41.25
Boiling Point (°C)
a.
b.
London dispersion forces
Dipole-induced dipole forces
c.
d.
H2Te
-2
Hydrogen bonding
Nonpolar covalent bonding
24. Gold metal can be mined by leaching the ores with cyanide according to the equation 8NaCN + 4Au + 2H2 O +
O2 ⟶ 4Na[Au(CN)2 ] + 4NaOH. If 10.00 g of each reactant (NaCN, Au, H2O, and O2) are reacted, which will be
the limiting reactant?
a. NaCN
b. Au
c. H2O
d. O2
25. How many milliliters of 0.131 M BaCl2 is required to react completely with 42.0 mL of 0.453 M Na2SO4? The
net ionic equation for the reaction is Ba2+ (aq) + SO24 (aq) ⟶ BaSO4 (s).
a. 12.1
b. 72.6
c. 145
d. 290
26. In the reaction given in Question #24, which reactant is the oxidizing agent?
a. NaCN
b. Au
c. H2O
d.
O2
27. When a 45.0 g sample of an alloy at 100.0 °C is dropped into 100.0 g of water at 25.0 °C, the final temperature is
37.0 °C. What is the specific heat capacity of the alloy in J/g∙°C? The specific heat capacity of water is 4.184
J/g∙°C.
a. 0.423
b. 1.77
c. 9.88
d. 48.8
28. A student mixes 100 mL of 0.50 M NaOH with 100 mL of 0.50 M HCl in a foam cup and measures a temperature
increase of ∆T1. The experiment is then repeated using 200 mL of each solution, and a temperature increase of ∆T2
is measured. If no heat is lost to the surroundings or absorbed by the cup, what is the relationship between ∆T1
and ∆T2?
a. ∆T2 = 4∆T1
b. ∆T2 = 2∆T1
c. ∆T2 = 0.5∆T1
d. ∆T2 = ∆T1
29. Using the data given, calculate the ∆H°rxn for the combustion
of methanol according to the equation 2H3 COH + 3O2 ⟶
2CO2 + 4H2 O in kJ/mol.
a. -1620
b. -63.0
c. +1620
d. +63
Bond
C–H
C–O
C=O
O=O
O – H (H2O)
O – H (H3COH)
Bond Energy (kJ/mol)
401.92
384.93
799.0
498.36
497.10
440.2
3
CHEM 1120 Practice Final Exam
30. Given the following reactions:
CS2 (l) + 3O2 (g) ⟶ CO2 (g) + 2SO2 (g)
∆H°rxn = -1077 kJ⁄mol
°
H2 (g) + O2 (g) ⟶ H2 O2 (l)
∆Hrxn = -188 kJ⁄mol
1
H2 (g) + O2 (g) ⟶ H2 O(l)
∆H°rxn = -286 kJ⁄mol
2
Calculate the value of ∆H°rxn for the reaction:
CS2 (l) + 6H2 O2 (l) ⟶ CO2 (g) + 6H2 O(l) + 2SO2 (g)
a. -1151
b.
-11751
c.
-1665
d.
-3921
31. The standard molar enthalpy of formation for nitrogen dioxide corresponds to the enthalpy change for which of the
following reactions?
a. N(g)+ 2O(g) ⟶ NO2 (g)
c. 1
N (g) + O2 (g) ⟶ NO2 (g)
2 2
1
b. 1
d.
N2 O4 (g) ⟶ NO2 (g)
NO(g) + O2 (g) ⟶ NO2 (g)
2
2
32. Calcium carbonate decomposes according to the equation CaCO3 (s) ⟶ CaO(s) + CO2 (g). What mass of
CaCO3, in grams, will produce 8.0 L of CO2, measured at STP?
a. 4.5
b. 12.5
c. 36
d. 280
33. 23.0 g of a monoatomic gas is held in a 7.50 L vessel at 27.0 °C and 685 torr. What is the identity of this gas?
a. He
b. Ne
c. Kr
d. Rn
34. An equal number of argon and xenon atoms are dispensed into the same reactor, maintained at a constant
temperature. Which of the following statements is false?
a. The xenon atoms have a higher average kinetic energy than the argon atoms.
b. The argon atoms are travelling at a higher velocity than the xenon atoms.
c. There are more moles of xenon gas than argon gas in the reactor.
d. The partial pressures of each gas in the reactor are equal.
35. Cyclohexanol has a higher boiling point than diethylamine. Given this information, for which of the following
properties will diethylamine have a higher value than cyclohexanol?
a. Vapor pressure
b. Viscosity
c. Surface tension
d. Melting point
36. When a substance in the liquid state is vaporized and then condensed, the steps in the process are...
a. …both endothermic.
c. …exothermic and endothermic, respectively.
b. …endothermic and exothermic, respectively.
d. …both exothermic.
37. Tungsten crystallizes with a body centered cubic (bcc) structure. How many atoms of tungsten are in one unit
cell?
a. 2
b. 4
c. 9
d. 14
4
CHEM 1120 Practice Final Exam
as the
Pressure
38. Using the phase diagram at right, what phase changes would occur
substance transitioned from point A to point B, then to point C?
a. Melting, boiling
b. Freezing, condensing
c. Melting, condensing
d. Freezing, boiling
·
·
A
B
·
·
C
D
Temperature
39. Which of the following substances will be most soluble in H2O(l)?
a. CS2
b. NH3
c. SiH4
d.
PCl5
40. Glycerin (C3H8O3) is a nonvolatile nonelectrolyte. What is the vapor pressure, in torr, of the solution formed by
dissolving 50.0 g of glycerin in 500.0 g of water at 25 °C? The vapor pressure of pure water at this temperature is
23.8 torr.
a. 21.6
b. 23.3
c. 24.3
d. 26.2
41. Which of the following aqueous solutions will have the highest freezing point?
a. 0.50 molal CaCl2
b. 0.30 molal KI
c. 0.90 molal glucose
d.
0.20 molal NaNO3
42. For which of the following processes is the ∆Srxn expected to be negative?
I.
Sugar dissolving in water
II. Condensing steam
III. Calcium carbonate decomposing into calcium oxide and carbon dioxide
a. I only
b.
II only
c.
I and III
d.
II and III
43. For the reaction NH4 Cl(s) ⇌ NH3 (g) + HCl(g), the ∆H°rxn = +176 kJ/mol and the ∆G°rxn = +91.2 kJ/mol. What
is the value of ∆G, in kJ/mol, for this reaction at 500 K?
a. -318
b. -33.7
c. +33.7
d. +318
44. For the dissociation of phosphoric acid in water, the ∆H°rxn = -8.0 kJ/mol and the ∆S°rxn = -67.8 J/mol∙K. How
will the spontaneity of this reaction be affected by the temperature?
a. The reaction is spontaneous at all temperatures.
b. The reaction will be spontaneous at high temperatures.
c. The reaction will be spontaneous at low temperatures.
d. The reaction is nonspontaneous at all temperatures.
45. The numerical value of the equilibrium constant for a given reaction can be changed by which of the following?
a. Adding a catalyst.
c. Increasing the concentration of a reactant.
b. Decreasing the volume of the reaction vessel.
d. Changing the temperature of the reaction.
5
CHEM 1120 Practice Final Exam
46. Given the following reactions:
2N2 (g) + O2 (g) ⇌ 2N2 O(g)
K = 4.37×10-37
N2 (g) + CO2 (g) ⇌ N2 O(g) + CO(g)
K = 5.39×10-64
Calculate the value of K for the reaction:
CO(g) +
a. 1.86x1063
b.
1.23x1045
1
O (g) ⇌ CO2 (g)
2 2
c.
8.11x1026
d.
2.36x10-26
47. For a certain reaction under a set of initial conditions, the ∆Grxn = -20.0 kJ/mol. What does this indicate about the
direction of the reaction as it proceeds to equilibrium?
a. Q > K, so the reaction will proceed to the right to reach equilibrium.
b. Q > K, so the reaction will proceed to the left to reach equilibrium.
c. Q < K, so the reaction will proceed to the right to reach equilibrium.
d. Q < K, so the reaction will proceed to the left to reach equilibrium.
48. Consider the hypothetical reaction AB3 ⇌ A + 3B. What is the equilibrium constant expression if only 0.1 M
AB3 is present initially and the equilibrium concentration of A is equal to x?
a. x - 3x
b.
c.
d. x ⋅ (3x)3
x ⋅ x3
x - x3
0.1 - x
(0.1 - 3x)3
(0.1 - x)3
0.1 - x
49. For the exothermic reaction 2H2 (g) + CO(g) ⇌ CH3 OH(g) at equilibrium, which of the following changes will
result in an increase in the amount of CH3OH present once the system re-establishes equilibrium?
a. Removing H2(g).
c. Decreasing the volume of the vessel.
b. Increasing the temperature.
d. Adding a suitable catalyst.
50. What is the conjugate base of HAsO42-?
a. H3AsO4
b. H2AsO4-
c.
HAsO42-
51. Which of the following correctly ranks the acids in order of increasing strength?
a. HBr < HI
b. HF < H2O
c. H3PO4 < H3PO3
d.
AsO43-
d.
HBrO3 < HIO3
52. A 0.15 M solution of a weak acid is found to be 1.3% ionized. What is the Ka of this acid?
a. 1.3x10-2
b. 2.0x10-3
c. 1.1x10-3
d. 2.6x10-5
53. What is the pH of a 0.30 M solution of hydrazine (pKb = 5.9)?
a. 3.2
b. 5.9
c. 8.1
d.
10.8
54. A solution of which of the following salts will be neutral?
a. NaNO2
b. (NH4)2SO4
c.
d.
CaF2
KBr
55. What is the pH of a solution formed by the addition of 0.020 moles of NaOH to a 1.0 L of a 0.040 M solution of
lactic acid (pKa = 3.86)? Assume the volume remains constant.
a. 1.70
b. 2.77
c. 3.56
d. 3.86
6
CHEM 1120 Practice Final Exam
56. For the titration of ammonia with hydrochloric acid, the pH at the equivalence point will be:
a. Less than 7.0
b. Equal to 7.0
c. Greater than 7.0
d. Exactly 0
57. What is the value of the solubility product constant (Ksp) of magnesium hydroxide if its solubility in water is
1.6x10-4 mol/L?
a. 1.6x10-11
b. 2.6x10-8
c. 3.2x10-4
d. 4.1x10-12
58. What will happen when 100. mL of a 0.0600 M Mg(NO3)2 solution is added to 50.0 mL of a 0.0600 M Na2C2O4
solution? The Ksp of MgC2O4 = 8.6x10-5.
a. No precipitate will form.
b. A precipitate forms, and excess Mg2+ remains in solution.
c. A precipitate forms, and excess C2O42- remains in solution.
d. A precipitate forms, and neither ion remains in solution.
59. Addition of Na2SO4(aq) to a saturated solution of BaSO4 will result in…
a. …no change in the [Ba2+].
c. …precipitation of additional BaSO4.
b. …dissolving of additional BaSO4.
d. …a decrease in the Ksp of BaSO4.
60. Given the unbalanced reaction Cu2 O3 + Cl- ⇌ Cu2+ + HClO2 , which takes place in acidic solution, what is the
coefficient of water in the balanced reaction equation?
a. 2
b. 4
c. 5
d. 6
61. Which of the following statements regarding a voltaic cell is true?
a. The reaction proceeds so as to generate a negative voltage.
b. Reduction occurs at the anode.
c. Anions flow to the anode through the wire.
d. Voltaic cells convert chemical energy into electrical work.
62. Given the following half-reactions:
Ag+ + e- ⇌ Ag
Al3+ + 3e- ⇌ Al
E°red = 0.7996 V
E°red = -1.662 V
Calculate the value of E°cell, in volts, for the reaction:
3Ag+ + Al ⇌ 3Ag + Al3+
a. 4.061
b.
2.462
c.
-2.462
d.
-4.061
63. Given the reaction Sn(s) + 4OH- (aq) + 2Pt2+ (aq) ⇌ SnO2 (s) + 2H2 O(l) + 2Pt(s) for which E°cell = 2.13 V, what
is the value of Ecell, in volts, when the [OH-] = 1.00x10-5 M and [Pt2+] = 3.00x10-3 M at 25.0 °C?
a. 1.76
b. 2.02
c. 2.24
d. 2.50
64. Under certain conditions, the average rate of appearance of oxygen gas in the reaction 2O3 ⇌ 3O2 is 1.2x10-3
atm/s. What is the average rate of disappearance of O3 in atm/s?
a. 8.0x10-4
b. 1.2x10-3
c. 1.8x10-1
d. 5.3x10-3
7
CHEM 1120 Practice Final Exam
65. A student studying the gas phase reaction CH3 Cl + H2 O ⇌ CH3 OH + HCl obtains the data in the table below.
What are the orders with respect to each reactant?
Exp #
1
2
3
a.
b.
CH3Cl is 1st order; H2O is 1st order
CH3Cl is 2nd order; H2O is 1st order
Initial Concentration (M)
CH3Cl
H2O
0.100
0.200
0.200
0.200
0.200
0.400
c.
d.
Initial Rate
(M/s)
0.728
1.45
5.81
CH3Cl is 1st order; H2O is 2nd order
CH3Cl is 2nd order; H2O is 2nd order
66. A plot of reactant concentration as a function of time gives a straight line. What is the order of the reaction for
this reactant?
a. Zeroth
b. First
c. Second
d. Third
67. A change in temperature from 10 °C to 20 °C is found to double the rate of a particular chemical reaction. How
did the change in temperature affect the reacting molecules?
a. The average kinetic energy of the molecules is doubled.
b. The average speed of the molecules is doubled.
c. The number of collisions per unit time is doubled.
d. The number of molecules above the reaction energy threshold is doubled.
68. What will happen to the value of the rate constant and equilibrium constant when increasing the temperature of
reactants that are known to undergo an endothermic reaction?
a. The value of both the rate constant and the equilibrium constant increase.
b. The value of the rate constant increases, but the value of the equilibrium constant decreases.
c. The value of the rate constant decreases, but the value of the equilibrium constant increases.
d. The value of both the rate constant and the equilibrium constant decrease.
69. Which of the following isotopes is most likely to undergo positron decay?
a. 115B
b. 43
c. 190
23V
74W
d.
266
Sg
106
70. The activity of a radioisotope is 3.000x103 counts/minute initially, and 2.736x103 counts/minute 48.00 hours later.
What is the half-life of this isotope in hours?
a. 831
b. 521
c. 361
d. 1.44
8
CHEM 1120 Practice Final Exam
Answer Section
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C
C
D
B
B
A
C
C
C
D
D
D
A
C
D
D
B
D
A
B
A
C
C
B
C
D
B
D
A
C
C
C
C
A
A
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B
A
A
B
B
D
B
C
C
D
B
C
D
C
D
A
D
D
C
D
A
A
B
C
B
D
B
A
A
C
A
D
A
B
C
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