Download Final Exam Practice-2017

Chemistry 30:Final Exam Practice
Unit 1: Materials Science
1. What is a valence electron?
a) An electron in the inner orbital of an atom. c) An electron in the outermost orbital of an atom.
b) An electron in the middle orbital of an atom. d) Any electron in an atom.
How many valence electrons in the following atoms/ions?
2. Se
a) 16
b) 6
c) 3
d) 34
3. Ca
a) 20
b) 2
c) 4
d) 40
4. Cl1-
a) 17
b) 7
c) 6
d) 8
5. Sr2+
a) 38
b) 2
c) 8
d) 0
6. Xe
a) 8
b) 18
c) 54
d) 0
7. The number of valence electrons can be found on the periodic table by looking at the:
a) Period
b) Group
c) Atomic number
d) atomic mass
8. Which of the following Lewis diagrams is drawn incorrectly?
a)
b)
c)
d)
9. Which of the following Lewis diagrams for an ion is correct?
a)
b)
c)
d)
10. Which of the following Lewis Diagrams for an ionic compound is incorrect?
a)
b)
c)
d)
11. Which of the following representations shows the Lewis symbols for the formation of potassium
chloride?
12. The Lewis structure for sulfur trioxide is shown here. What type of bond is
formed between the electrons indicated?
a) Single bond
b) double bond
c) triple bond
d) ionic bond
13. Which of the following elements will NEVER make an octet?
a) B
b) Br
c) H
d) C
e) A and C
14. A triple bond drawn in a Lewis structure is a symbol for ___ electrons being shared. Ex)
a) 2
b) 3
c) 6
d) 8
15. Which of the following has the longest bond(s)?
16. In the compound CCl4, how many total valence electrons are present?
a) 4
b) 28
c) 32
d) 8
17. How many valence electrons are available in the ion SO42-?
a) 30
b) 32
c) 28
d) 24
18. Which of the following is a Lewis Structure that accurately represents the compound, BF3?
a)
b)
c)
d)
19. Which of the following is a Lewis Structure that accurately represents the compound, NH3?
a)
b)
c)
d)
20. Examine the Lewis structure for propanal, C3H6O. Which of the following descriptions
about its structure is correct?
a) This is a correct Lewis structure
b) There are too many electrons in this diagram. The lone pair on carbon should be removed.
c) There are too many electrons in this diagram. The lone pair of electrons on carbon should make a
double bond with hydrogen.
d) There are too many electrons in this diagram. The lone pair on carbon should instead be a double
bond with one of oxygen’s lone pairs.
21. The molecules CO2 and SO2 have very similar formulas yet make a different shape. What is different
about their Lewis structures that give them a different shape?
a) CO2 has a different number of electrons than SO2; therefore CO2 needs 2 double bonds and SO2
only needs one double bond.
b) CO2 has a different number of electrons than SO2; therefore SO2 needs 2 double bonds and CO2
only needs one double bond.
c) CO2 has a different number of electrons than SO2; therefore C needs a lone pair while S does not.
d) The above statement is incorrect. Both CO2 and SO2 have the same Lewis Structure.
22. Circle the correct answer regarding resonance structures/forms:
a) The molecule IS / IS NOT rapidly oscillating between different forms.
b) There is ONE / MORE THAN ONE form of the of the actual molecule and the bond lengths of
single bonds vs doubles bonds between the atoms are DIFFERENT / AN AVERAGE .
c) We draw ONE / MORE THAN ONE Lewis structure to describe the real structure.
23. Which of the following have the strongest attraction?
a) Ionic bond
b) Covalent bond
c) London dispersion d) Dipole-Dipole
24. Which of the following is the weakest Van der Waals force?
a) Hydrogen bond b) ion-dipole
c) dipole-dipole
e) H bond
d) London dispersion
25. Which term describes the EQUAL sharing of electrons between two atoms with similar
electronegativity?
a) Polar covalent bond b) Non-polar covalent bond c) ionic bond d) intermolecular force
26. Match the following forces to their correct description:
a) Ionic/Ionic Crystal
b) Metallic
c) Covalent
d) Van der Waals
e) Covalent Network
___ Moderately high melting point, high boiling point, conducts electricity, insoluble, malleable.
___ Low melting and boiling points, not a conductor, insoluble in water, soft.
___ Weak forces between molecules, include surface tension and dipoles.
___ High melting and boiling point, good conductor in solution, soluble, hard, brittle.
___ Very high melting and boiling point, poor conductor, insoluble and extremely hard.
27. Which class of organic compound contains at least one double bond?
a) Alkane
b) Alkene
c) Alkyne
d) Aromatic
28. How many hydrogen atoms are found in a molecule of octene?
a) 8
b) 14
c) 16
d) 18
29. How many carbon atoms are found in a molecule of 2-methyl-3-pentene?
a) 5
b) 6
c) 7
d) 8
30. What is the IUPAC name of the following molecule?
a) 1,4-dimethyl-2-ethylcyclohexane
c) 3-ethyl-1,4-dimethylcyclohexane
b) 2-ethyl-1,4-dimethylcyclohexane
d) 1-ethyl-2,5-dimethylcyclohexane
31. What is the IUPAC name of the following molecule?
a) 2,4,4-methylpentane
c) 2,2,4-trimethylpentane
b) 2,2,4-methylpentane
d) 2,4,4-trimethylpentane
32. What is the IUPAC name of the following molecule?
a) 1,2-dimethyl-3-ethylbenzene
b) 1-ethyl-2,3-dimethylbenzene
c) 1-ethyl-5,6-dimethylcyclohexane
d) 1-ethyl-2,3-dimethylcyclohexane
e)
33. What is the IUPAC name of the following molecule?
a) 3-methyl-4-heptene c) 3-methyl-3-heptene
b) 5-methyl-3-heptene d) 5-methyl-3-heptyne
34. What is the IUPAC name of the following molecule?
a) 2,2,6-trimethyl-3-octene
b) 3,7,7-trimethyl-5-octene
c) 2-ethyl-6,6-dimethyl-4-heptene
d) 6-ethyl-2,2-dimethyl-3-heptene
35. Which of the following is NOT a structural isomer of the diagram to the right?
a)
b)
c)
36. Consider the following molecule:
To which class of organic compounds does this molecule belong?
a) Alkyl halide
b) aryl halide
c) alcohol
d) Ether
e) Amine
To which class of organic compounds does this molecule belong?
a) Alkyl halide b) aryl halide
c) alcohol
d) Ether
e) Amine
37. Consider the following molecule:
38. Consider the following molecule:
To which class of organic compounds does this molecule belong?
a) Alkyl halide b) aryl halide
c) alcohol
d) Amide
e) Amine
39. Which of the following molecules is an alcohol?
a) Ba(OH)2
b)
d)
c)
40. What is the correct IUPAC name of the following molecule?
a) Ethyl butyl ether
c) hexanal
b) Butyl ethyl ether
d) 2-hexanol
CH3-CH2-O-CH2-CH2-CH2-CH3
41. Which of the following molecules is an aldehyde?
a)
b)
c)
42. Which of the following molecules is an amide?
a)
b)
c)
43. Consider the following polymer, polymethyl methacrylate:
Which of the following is a monomer of polymethyl methacrylate?
a)
b)
c)
d)
Unit 2: Equilibrium
44. A closed system is one in which:
a) Matter can enter or exit
b) Matter cannot enter or exit
c) a steady state can be established
d) A and C
45. Which of the following is true of an equilibrium system:
a) Changes occur at the visible level
c) There are no changes at the molecular level
b) The reaction concentrations change d) The amount of products & reactants can be different
46. Le Chatelier’s principle states that when a _______ is applied to a system in equilibrium, the
equilibrium will shift to _____________.
a) Reactant, make more of.
c) Product, make more of it.
b) Stress, relieve it.
d) Stress, increase it.
47. What happens to a reaction at equilibrium when the temperature of an endothermic reaction is
increased?
a) The reaction makes more products
c) the reaction is unchanged.
b) The reaction makes more reactants d) the reaction will shift in reverse.
48. Consider the following equilibrium equation: Na2SO4(s) ↔ 2Na+(aq) + SO42-(aq).
Which of the following will cause a shift of the equilibrium system?
a) Addition of a catalyst b) increase in pressure c) removal of Na2SO4(s)
d) addition of Na+(aq)
49. After examining the following reaction, determine which two changes would BOTH cause a shift in the
same direction:
System: 2 NO (g) + O2 (g)  2 NO2 (g) + heat
a)
b)
c)
d)
An increase in temperature and an increase in O2 (g)
An increase in pressure and an increase in NO (g)
A decrease in NO (g) and a decrease in temperature.
A decrease in temperature and a decrease in pressure.
50. What happens to the following equilibrium if the concentration of H2 is decreased?
System: FeO (s) + H2 (g)  Fe (s) + H2O (g) + heat
a) The reaction shifts forward
b) The reaction shifts in reverse
c) The reaction is unchanged
d) The reaction will shift to the right side
Use the given equilibrium equation for the following 3 questions: CH4(g) + H2O(g) ↔ CO(g) + 3H2(g)
51. The equilibrium constant expression for the above reaction is:
a) Keq = [CH4][ H2O]
c) Keq = [CH4][H2O]
3
[CO][H2]
[CO]3[ H2]
b) Keq = [CO][ H2]3
[CH4][ H2O]
d) Keq = [CO]3[ H2]
[CH4][H2O]
52. At equilibrium, the concentrations were found to be: [CH4]=2M, [ H2O]=3M, [CO]=2M, [H2]=4M.
What is the value of Keq?
a) 21
b) 1.3
c) 4
d) 0.05
53. Which of the following would be used to increase the concentration of CO(g)?
a) Increase the pressure
c) Add H2O(g)
b) Add a catalyst
d) Add H2(g)
54. A mixture of 0.200 M of NO, 0.100 M of H2 and 0.20 M of H2O is placed in a vessel. The following
equilibrium is established:
2NO(g) + 2H2(g) ↔ N2(g) + 2H2O(g)
At equilibrium [NO] = 0.124 M. What is the Keq? (Use the following ICE chart as a guide)
N2
2H2O
2NO
2H2
I
0.20
0.200
0.100
C
E
0.124
a) 330
b) 3.0 x 10-3
c) 7.2
d) 3.5
55. When calculating the equilibrium constant expression (Keq) for a chemical reaction, a small Keq
represents:
a) A spontaneous reaction
d) both a and c
b) A non-spontaneous reaction
e) both b and c
c) The products are favoured over the reactants
56. The equation for the dissolving (dissociation equation) of sodium sulfide in water is represented by
which of the following?
a) Na2S (s) ↔ Na2+ (aq) + S2- (aq)
c) Na+ (aq) + S2- (aq) ↔ Na2S (s)
+
2b) Na2S (s) ↔ 2Na (aq) + S (aq)
d) 2Na+ (aq) + S2- (aq) ↔ Na2S (s)
57. Which of the following substances would NOT cause NaCl to precipitate from a saturated solution when
added to it? (HINT: common ion effect)
a) HCl
b) Al2Br3
c) AgCl
d) Na2CO3
58. Which of the following is a spectator ion in the chemical reaction shown by this total ionic equation:
Na+(aq) + Br-(aq) + Ag+(aq) + NO3-(aq)  AgBr(s) + Na+(aq) + NO3- (aq)
a) Na+
b) Br-
c) Ag+
d) AgBr
59. When ammonium phosphate ((NH4)3PO4 (aq) ) is added to a solution of iron (III) chloride (FeCl3 (aq)),
a precipitate results. The net ionic equation for this reaction is:
a)
b)
c)
d)
(NH4)3PO4 (aq) + FeCl3 (aq)3NH4Cl (aq) + FePO4 (s)
3NH4+(aq) + PO43- (aq) + Fe3+ (aq) + 3Cl- (aq)  3NH4+(aq) + 3Cl- (aq) + FePO4 (s)
Fe3+ (aq) + PO43- (aq)  FePO4 (s)
3NH4+(aq) + 3Cl- (aq)  3 NH4Cl (aq)
Answer the next 3 questions using the solubility curve provided:
60. Based on the solubility curve provided, which of the following
terms best describes a solution at 600C that contains 40g
KNO3/100g of water?
a) Saturated
c) Unsaturated
b) Supersaturated
d) none of the above
61. Suppose a solution at 700C contains 60g KNO3/100g water. Based
on the solubility curve provided, what additional mass of KNO3
would be required to saturate the solution at the same
temperature?
a) ≈70g
b) ≈10g
c) ≈130 g
d) ≈20g
62. Suppose a solution at 400C contains 60g KNO3/100g water. Using the solubility curve, what type of
solution would result if the temperature is heated up to 1000C?
a) Saturated
b) unsaturated
c) Supersaturated
d) none of the above
63. A saturated solution of Mg(OH)2 at 250C has a solubility of 1.12 x 10-4 M. The following equilibrium
was established:
Mg(OH)2 (s)
Mg2+ (aq) + 2OH- (aq)
What is the value of the solubility product constant, Ksp at 250C?
a) 2.51 x 10-8
b) 1.25 x 10-8
c) 5.62 x 10-12
d) 5.02 x 10-8
64. The following equilibrium was established for a saturated solution of MgCO3 (s) at 250C.
MgCO3 (s)
Mg2+ (aq) + CO32- (aq)
If the Ksp value is 6.8 x 10-6 @ 250C, what is its solubility?
a) 4.6 x 10-11M
b) 2.6 x 10-3M
c) 6.8 x 10-6M
d) 1.9 x 10-2M
65. Solutions of lead (II) nitrate (Pb(NO3)2 (s)) and sodium chloride (NaCl) are mixed producing the
following reaction: Pb(NO3)2 (s) + 2 NaCl (aq)
PbCl2 (?) + 2 NaNO3 (aq)
After mixing, the Pb2+ concentration is 0.050 M and the Cl- concentration is 0.0010 M.
The Ksp of PbCl2 = 1.7 x 10-5. What does the value of the trial Ksp indicate?
a)
b)
c)
d)
It has a smaller value than the actual Ksp so a precipitate forms.
It has a larger value than the actual Ksp so a precipitate will form.
It has a larger value than the actual Ksp so a precipitate does not form.
It has a smaller value than the actual Ksp so a precipitate does not form
Unit 3: Acids and Bases
66. A Bronsted-Lowry Base is described as:
a) H+ donor
b) OH- donor
c) H+ acceptor
67. Sulfuric acid is considered to be a:
a) Monoprotic acid
b) diprotic acid
d) OH- acceptor
c) triprotic acid
d) tetraprotic acid
68. Which of the following shows the second ionization of phosphorous acid?
a) H2PO3- (aq) + H2O (l) ↔ HPO3-2 (aq) + H3O+ (aq)
b) H3PO3 (aq) + H2O (l) ↔ H2PO3- (aq) + H3O+ (aq)
c) HPO3-2 (aq) + H2O (l) ↔ PO3-3 (aq) + H3O+ (aq)
d) BO3-3 (aq) + H2O (l) ↔ BO3-3 (aq) + H2O (aq)
69. Identify the substance that acts as an acid one time and another time as a base:
HCO3- (aq) + H2PO3- (aq) ↔ H2CO3 (aq) + HPO32-(aq)
H2PO3-(aq) + SO42- (aq) ↔ HSO4- (aq) + HPO32-(aq)
HCO3- (aq) + HTe- (aq) ↔ CO32- (aq) + H2Te (aq)
a) HCO3- (aq)
b) HTe-
c) H2PO3-(aq)
d) HSO4- (aq)
70. Identify the FALSE statement about the following equilibrium: HBr(aq) + H2O (l) ↔ H3O+(aq) + Br-(aq)
a) HBr and Br- are acting as a conjugate acid-base pair.
b) Br- is acting as an acid.
c) H2O is acting as a base.
d) The weak acid will be more concentrated than the strong acid at equilibrium.
71. Which of the following is the correct Kb for the weak base C6H5NH2?
a) Kb = [C6H5NH2]
b) Kb = [C6H6NH2+][OH-] c) Kb = [C6H5NH3+][OH-]
+
[C6H5NH3 ][OH ]
[C6H5NH2]
[C6H5NH2]
72. Which of the following is not amphiprotic?
a) HSO4b) H2PO3c) HCl
73. The conjugate acid of HSO4 is:
a) SO42b) H2SO4
c) SO4+
74. If the pH of a solution is 2.00,
a) It is considered to be neutral
b) It is strongly acidic
d) HCrO4d) none of the above
c) it is strongly basic
d) the [OH-] is larger than the [H+]
75. The pOH of a substance is 8.60. What is its pH?
a) 4.0 x 10-6
b) 5.40
c) 2.5 x 10-9
d) 7.00
76. The [H+] of a substance is 3.6 x 10-3M. What is the pOH?
a) 2.44
b) 11.56
c) 2.8 x 10-12
d) basic
77. What is the [H+] of 0.500M HCl, a STRONG acid?
a) 0.500M
b) 2.0 x 10-14 M
c) 0.316 M
d) 0.301 M
78. What is the [H+] of a neutral solution?
a) 7.00 M
b) 1.0 x 10-7 M
d) none of the above
c) 2.00
79. What is the [OH-] of 2.5M Al(OH)3, a STRONG base?
a) 2.5 M
b) 5.0 M
c) 4.0 x 10-15 M
d) 7.5
80. HNO2 is a weak acid. It ionizes as follows: HNO2 (aq) ↔ H+ (aq) + NO2- (aq). In a 1.0 M solution of
HNO2, the equilibrium pH is 1.64. Calculate the Ka for HNO2.
I
C
E
a) 0.0235
H+ (aq)
0
b) 0.471
NO2- (aq)
0
HNO2 (aq)
1.0
c) 5.4 x 10-4
d) 4.21
81. In a titration experiment, 155 mL of 6.5mol/L HCl are added to 250mL of Al(OH)3. What is the
concentration of the base? (MaVa=MbVb)
a) 1.3 M
b) 4.0 M
c) 12 M
d) 0.25 M
82. In a titration experiment, what volume of 5.5 mol/L phosphoric acid would be needed to completely
react 0.8L of 0.550mol/L KOH? (MaVa=MbVb)
a) 0.027 L
b) 0.080 L
c) 0.24 L
d) 27 L
83. Which of the following is not an indicator?
a) Phenolphthalein
b) Litmus
c) Hydrochloric acid d) Bromthymol Blue
84. The end point of a titration is the point at which:
a) The moles of H+ from the acid equals the moles of OH- from the base
b) The indicator in a titration changes to the exact right colour and you stop titrating
c) The solution always reaches a pH of 7.00
d) You are exactly neutralized
Unit 4: Oxidation-Reduction
85. An element that is reduced is considered to be:
a) An oxidizing agent
b) a reducing agent
c) lost electron s
86. Which of the following best represents oxidation?
a) Gain of electrons
b) Change in oxidation number from 0 to -2
c) loss of electrons
d) X3-  X5-
d) a and c
87. The oxidation number of the bolded element in H2CO3 is:
a) +4
b) -4
c) +6
d) -6
88. The oxidation number of the bolded element in AsO43- is:
a) -3
b) +3
c) -5
d) +5
89. The oxidation number of the bolded element in N2H4 is:
a) -4
b) +4
c) -2
d) +2
90. Which of the following equations does NOT represent a redox reaction?
a) LiOH + HNO3  LiNO3 + H2O
c) MgI2 + Br2  MgBr2 + I2
b) Ag + S  Ag2S
d) b and c
91. What is the element that is oxidized in the following reaction?
2AgNO3 (aq) + Cu (s)  Cu(NO3)2 (aq) + 2Ag (s)
a) Ag
b) N
c) Cu
d) O
92. What is the element that is reduced in the following reaction? Br2 (g) + 2HI (aq)  2HBr (aq) + I2 (l)
a) Br
b) H
c) I
93. Which of the following is the correct balanced half reaction for I2O5  I2 in a basic solution?
a) 10H+ + I2O5 + 5e-  I2 + 5H2O
c) 5H2O + I2O5 + 5e-  I2 + 10 OHb) 10H+ + I2O5 + 10e-  I2 + 5H2O
d) 5H2O + I2O5 + 10e-  I2 + 10 OH94. Which reactant pair will result in a spontaneous reaction?
a) Ag + Pb2+
b) Pb2+ + H2
c) Cs + Au3+
95. Which of the following is most likely to be reduced if placed in an electrochemical cell?
a) Cd2+
b) Cu2+
c) Ce3+
d) Co3+
96. Which of the following is most likely to be oxidized if placed in an electrochemical cell?
a) Pt
b) Cr
c) K
d) F2
97. The reaction between copper and gold (III) chloride is shown below.
Cu + AuCl3  Au + CuCl2
What are the half reactions for this redox reaction?
a) Cu  Cu2+ + 2e- and Au  Au3+ + 3ec) Cu2+ + 2e-  Cu and 2Cl- + 2e- Cl2
2+
3+
b) Cu  Cu + 2e- and Au + 3e-  Au
d) Au  Au3+ + 3e- and 2Cl- + 2e- Cl2
Use the electrochemical cell diagram provided for the
following 4 questions:
98. Which of the following is the oxidation half-reaction
from the electrochemical cell provided?
a) Mg2+ + 2e-  Mg
c) Ag+ + e-  Ag
b) Mg  Mg2+ + 2ed) Ag  Ag+ + e99. What is the anode?
a) Mg
100.
b) Mg2+
c) Ag
d) Ag+
What would be the E0cell (reduction potential) for the cell?
a) -3.1716 V
b) 3.1716 V
c) 1.5724V
d) -1.5724V
101.
Which of the following is the correct cell notation for the overall redox reaction in the above
electrochemical cell?
a) Mg│Mg2+║Ag+│Ag
c) Ag+│Ag║ Mg│Mg2+
b) Mg2+│Mg║Ag│Ag+
d) Ag│Ag+║ Mg2+│Mg
102.
In an electrochemical cell, where does reduction occur?
a) At the salt bridge
b) at the cathode
c) at the anode
d) in the copper wire
103.
A sacrificial anode is often connected to ships to prevent corrosion. If the sacrificial anode
prevents the oxidation of iron, Fe(s)  Fe2+ + 2e-, what could the anode be made of?
a) Copper
b) Bismuth
c) Gold
d) Sodium