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Chemistry 122 Mr. McIsaac
FINAL EXAM - Sample
Page 1 of 7
I. Multiple Choice + II. Problems
I.
Multiple Choice. Value = 50 points c/w 1 bonus. Do all 51 questions. On answer sheet, shade the letter of best answer.
1. CnH2n is the general form for the:
a. alkanes b. alkenes c. alkynes
d. aromatics
2. The empirically obtained molecular formula, C8H14(l) most likely represents an
a. alkane. b. alkene. c. alkyne. d. aromatic.
3. Which of the following is the formula of an alkene?
a. C6H6 b. C6H14 c. C6H12 d. C6H10
4. CH2=CH–CH2–CH3 is an example of a(n):
a. alkene b. unsaturated compound c. hydrocarbon
d. all of the above
5. Which of the following compounds contains no oxygen atoms?
a. glycerol b. methylethanoate c. propanone d. butanamide
6. An organic compound that contains nitrogen is:
a. 2-butyne b. methylamine c. ethylpropanoate
d. pentanoic acid
7. The English IUPAC name of CH3 — CH2 — CH2 — CH2 — CHOH — CH3 is
a. 1-methyl-1-pentanol. b. 5-methyl-1-pentanol. c. 2-hexanol. d. 5-hexanol.
8. The English IUPAC name for the isomeric compound illustrated below is:
a. 2,4-dibromobenzene
b. 3,5-dibromobenzene
c. 4,6-dibromobenzene
d. 1,3-dibromobenzene
9. The English IUPAC name (proper organic nomenclature) of the compound represented by the following structure is
CH3—CH==CH—CH3
a. butene b. 2-butene c. methylpropene d. dimethylethene
10. According to IUPAC rules, the English name for the structural model shown below is
CH3
|
CH3 — CH — CH — CH2 — CH3
|
CH3
a. 2,3-dimethylpentane. b. 2,3-diethylpentane. c. 2,3,4-trimethylbutane. d. 2-methyl-3,4-ethylbutane.
11. The best English IUPAC name for the following structural model is:
a. 2-phenylpropane
b. 2,2 dimethyltoluene
c. 1-propylbenzene
d. 1,1,1-trimethylbenzene
12. The best English IUPAC name for the following structural model is:
Cl
|
CH2 — CH2 — CH2 — C — CH3
|
|
OH
Cl
a. 4,4-dichloro-1-pentanol b. 2,2-dichloro-1-pentanol c. 1,1-dichloro-1-methyl-4-hydroxybutane
d. 2,2-dichlorobutanol
Chemistry 122 Mr. McIsaac
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FINAL EXAM - Sample
13. The best English IUPAC name for the following structural model is:
CH3
O
|
||
CH3 — CH — CH2 — C — CH3
|
Cl
a. 2-chloro-2-methyl-4-oxypentane b. 2-chloro-2-methylmethanoate
d. 2-chloro-2-methyl-4-pentanone
c. 4-chloro-4-methyl-2-pentanone
14. The best English IUPAC name for the following structural model is:
CH3 — CH2 — CH2 — CH2 — C == O
|
OH
a. 1-hydroxypentanone b. 1-pentanoic acid c.pentanoic acid d. pentanal
15. The best English IUPAC name for the following structural model is: (Be careful to identify the LONGEST part of the parent chain!)
CH3 — CH — CH2 — CH2 — CH
|
||
CH2
O
|
CH3
a. 4-ethylpentanal b. 2-ethylpentanal c. 4-methylhexanal
d. 4-methylpentanone
16. The best English IUPAC name for the following structural model is:
O
||
CH3 — CH2 — C — O — CH3
d. 3-oxyethylmethyl ether b. methoxypropanone c. methylethanamide
17. The correct condensed formula for 5-methyl-2-hexyne is:
a. CH3CHCHCH3CH(CH3)CH3 b. CH3CHCHCH(CH3)CH3
d. methylpropanoate
c. CH3CCCH(CH3)CH3
d. CH3CCCH3CH(CH3)CH3
18. The compound below that would most likely undergo a substitution reaction is
a. butane b. 1-butyne c. 2-pentene d. methanoic acid + ethanol
19. Which of the following reactions results in a product that has a double bond?
a) substitution b) addition c) elimination d) hydrogenation
20. Which of the following could be involved in addition polymerization?
a. propane b. ethanol + propanoic acid c. butene d. chloroethane
21. A travel mug complete with hot coffee but without a lid is a(n)
a. closed system. b. open system. c. isolated system. d. insulated system.
22. The minimum amount of energy that a freezer removes from 2.50 x 102 g of water at 0.0°C to produce ice cubes at 0.0°C is
a. 27.9 kJ b. 84.4 kJ. c. 167 kJ. d. 1.50 x 103 kJ
23. Calculate the quantity of energy required to change 25.0 g of solid copper at 30.0°C to 1030.0°C. (The melting point of
copper is 1083.0°C.)
a. 801 J b. -27.1 kJ
c. 27.1 kJ d. 9.63kJ
24. Calculate the amount of energy released when 1.50 kg of ammonia is changed from gas to liquid.
a. -205.5 kJ b. -206 kJ c. -1940 kJ d. -2050 kJ
25. When 154 g of antifreeze absorbs 5045 J of energy from an engine, it heats from 21.0°C to 35.0°C. What is the specific
heat capacity of antifreeze in J/g·°C?
a. 0.427 b. 0.936 c. 2.34 d. 1.56
Chemistry 122 Mr. McIsaac
FINAL EXAM - Sample
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26. A student dissolves some KOH in a beaker of water. This process is represented by the dissociation equation:
KOH(s) —> K+(aq) + OH-(aq). Recorded temperatures: initial temperature of water = 18.5°C
final temperature of resulting solution =27.0°C
Based on this evidence, which statement below is justified?
a. The potential energy of KOH(s) is higher than the potential energy of K+(aq) + OH-(aq).
b. The kinetic energy of KOH(s) is higher than the kinetic energy of K+(aq) + OH-(aq).
c. KOH(s) ——> K+(aq) + OH-(aq) has a positive ÄH value.
d. The dissolving of KOH(s) in water is an endothermic process.
Next 2 questions: The heating curve was obtained by heating 0.50 g of sodium initially at 20.0°C in a closed container.
Hfus = 2.64 kJ/mol Hvap = 98.1 kJ/mol cNa(s) = 1.226 J/(gA°C) cNa(l) = 1.63 J/(gAC°) cNa(g) = 0.910 J/(gA°C)
27. The portion of the heating curve that indicates the change of liquid sodium from its melting to boiling point is:
a. B. b. C. c. D. d. E.
28. Which of the statements below is least accurate about the heating curve for sodium?
a. Line B is shorter than Line D because the molar enthalpy of fusion of sodium (or any substance) is less than its molar
enthalpy of vapourization.
b. The overall shape of the heating curve can be explained in terms of three kinetic energy changes and two potential
energy changes.
c. Lines A and C have almost equal slopes because the specific heat capacities of liquid and gaseous sodium are almost
equal.
d. The melting point of sodium is 98°C.
21. Which of the following equations represents a reaction in which the products can be classified as having higher potential
energy than the reactants?
a. 2 C2H6(g) + 7 O2(g) ——> 2 CO2(g) + 6 H2O(g) + 2857 kJ
b. 4 C(s) + 5 H2(g) ——> C4H10(g)
ÄHr = -125.6 kJ
c. C3H8(g) ——> C3H8(l)
d. H2O(s) ——> H2O(l)
30. Referring to the reaction below, how much heat is released if 42.0 g of lithium metal reacts?
2 Li(s) + 2 H2O(l) ——> 2 LiOH(aq) + H2(g) + 150.0 kJ
a. 3.57 kJ b. 454 kJ c. 908 kJ d. 0 kJ because no temperature change is indicated
31. Find the molar enthalpy of reaction for iron in the following equation.
4 Fe(s) + 3 CO2(g) ——> 3 C(s) + 2 Fe2O3(s) + 466 kJ
a. -117 kJ/mol b. +233 kJ/mol c. +466 kJ/mol d. -466 kJ/mol
32. The standard molar enthalpy of formation (Hf°) of the elements is arbitrarily set to:
a. 4.19 J/g·°C b. 22.4 kJ/mol c. 24.8 kJ/mol d. 0 kJ
Chemistry 122 Mr. McIsaac
FINAL EXAM - Sample
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33. Use the following equation to calculate the enthalpy change for the burning of graphite to carbon monoxide.
C(s) + O2(g) —> CO2(g)
ÄHf° = -393.5 kJ
2 CO + O2(g) —> 2 CO2(g)
ÄHr° = -565.7 kJ
2 C(s) + O2(g) —> 2 CO(g)
ÄHr° = ?
a. 172.2 kJ b. –221.3 kJ c. –172.2 kJ d. –959.2 kJ
34. Choose the most thermodynamically stable compound using the enthalpies of formation table (p. 531).
a. CO(g) b. H2O(g) c. NH3(g) d. NO2(g)
35. Calculate the enthalpy change for the following reaction, and determine which of the following answers is closest:
4 NH3(g) + 5 O2(g) —> 4 NO(g) + 6 H2O(l)
a. -905 kJ b. -1170 kJ c. 1350 kJ d. 1540 kJ
36. Equilibrium is theoretically defined as
a. a state of constant changes in observed macroscopic properties.
b. a state naturally achieved by a reaction when all changes stop.
c. two separate reactions occurring simultaneously.
d. a balance between forward and reverse processes of a reaction – microscopic (infinitesimally small) changes occurring in
both directions.
37. Nitrous acid is a weak acid, and only ionizes 8.1%, as shown by the following equation:
8.1%
HNO2(aq) º H+(aq) + NO2-(aq)
Which of the following is true for a 1.0 M solution of nitrous acid?
a. the products are favored
b. the equilibrium concentration of hydrogen ions is 8.1 M
c. the equilibrium concentration of hydrogen ions is 0.081 M
d. the equilibrium concentration of nitrous acid is 0.081 M
38. Which of the following best shows the equilibrium of an ice-water mixture at 0°C?
a. H2O(s) + energy º H2O(l)
b. H2O(s) º H2O(l) + energy
c. H2O(s) º H2O(l) º H2O(g)
d. H2O(l) º H+(aq) + OH-(aq)
39. Calculate the value of the equilibrium constant using the following information on concentrations measured at equilibrium:
2 SO2(g) + O 2(g) º 2 SO3(g)
0.33 mol/L 0.17 mol/L 0.27 mol/L
a. 0.25 b. 2.0 c. 3.9 d. 4.8
40. Which of the following does not properly express Le Chatelier's principle?
a. When two or more reactants are initially added, the percent yield established at equilibrium can be predicted.
b. When a stress is applied to a system at equilibrium, the system will respond with the opposite stress.
c. When a chemical system at equilibrium is disturbed by a change in a property of the system, the system adjusts in a way
that opposes the change.
d. When a chemical system at equilibrium has a stress applied to it that causes one side of the reaction to be affected, the
opposite side will also be affected as the system responds by trying to negate or take away the applied stress.
41. To suppress the following reaction, H2O(g) + C(s) + energy º CO(g) + H2(g), a chemical engineer could:
a. decrease the concentration of CO(g) d. increase the concentration of H2O(g) a. use low temperatures
d. use low pressures
42. If the following equilibrium mixture is heated, the color becomes a lighter in colour. The correct interpretation is that the
forward reaction is: N2O4(g) º 2 NO2(g)
brown
colorless
a. exothermic and the equilibrium has been shifted to the left.
b. exothermic and the equilibrium has been shifted to the right.
c. endothermic and the equilibrium has been shifted to the right.
d. endothermic and the equilibrium has been shifted to the left.
Chemistry 122 Mr. McIsaac
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FINAL EXAM - Sample
43. If additional chlorine gas is added to the following equilibrium system, which answer best describes the shift and net
concentrations after the newly established equilibrium: 2 NO(g) + Cl2(g) º 2 NOCl(g)
a. shift right; less NO(g); more Cl2(g); more NOCl(g)
b. shift right; more NO(g); less Cl2(g); less NOCl(g)
c. shift left; less NO(g); more Cl2(g); less NOCl(g)
d. shift left; more NO(g); more Cl2(g); less NOCl(g)
44. Which of the following adjustments would not increase the production of carbon disulfide?
CH4(g) + 2 H2S(g) + energy º CS2(g) + 4 H2(g)
a. heat the system
b. remove as much of the hydrogen as possible
c. increase pressure
d. add more methane
45. As a chemical engineering consultant, which of the following would be good options for you to suggest to optimize the
production of methanol, according to the reactions: CO(g) + 2 H2(g) º CH3OH(g) + energy
a. add more CO(g) and/or H2(g); remove some of the CH3OH(g); decrease temperature; increase pressure
b. remove some of the CO(g) and/or H2(g); decrease temperature; increase pressure
c. add more CO(g) and/or H2(g); increase temperature; increase pressure
d. add more CO(g) and/or H2(g); remove some of the CH3OH(g); increase temperature; decrease pressure
46. The concentration of OH in pure water in mol/L is:
a. 7 b. 14 c. 1.0 x 10-7 d. 1.0 x 10-14
47. What is the pH of a 0.050 M strong HCl(aq) solution (i.e. 100% ionization)?
a. 1.3 b. 1.5 a. 2.0 d. 5.0
48. When referring to water equilibrium, the product of the hydrogen ion and hydroxide ion concentrations is the:
a. pH b. pOH c. Keq d. Kw
49. If a 0.10 mol/L basic solution has [OH-(aq)] of 1.6 x 10-5 M. Calculate the pH.
a. 4.80 b. 9.20 c. 6.25 x 10-10 M d. 1.60 x 10-9 M
50. Calculate the [H+(aq)] of a benzoic acid solution that has a pOH of 11.40:
3.4 x 10-12 M b. 2.5 x 10-3 M c. 3.4 x 102 M d. 2.60
51. Theoretically, an oxidizing agent can be described as a substance that
a. loses electrons and becomes reduced. b. loses electrons and causes reduction.
d. gains electrons and becomes reduced.
c. gains electrons and causes oxidation.
52. The metal molybdenum, Mo, can react to produce MoO2(s). The half-reaction that explains the change in oxidation state of
molybdenum can be written
a. Mo(s) + 2 e- ——> Mo2+(s) b. Mo(s) ——> Mo2+(s) + 2 e- c. Mo 4+(s) + 4 e- ——> Mo(s)
d. Mo(s) ——> Mo4+(s) + 4 e53. The oxidation number of the chlorine in Ca(ClO3)2 is predicted to be
a. 0 b. +5 c. +6 d. +10
54. Predict the entity that can act as both an oxidizing agent and a reducing agent.
a. sodium ion b. iron metal c. lead(II) ion d. iron(III) ion
55. During the process of photosynthesis, 6 CO2(g) + 6 H2O(l) ——> C6H12O6(aq) + 6 O2(g)
a. carbon in carbon dioxide is oxidized.
b. hydrogen in water is reduced.
c. oxygen in carbon dioxide and/or water is oxidized.
d. oxygen in glucose is oxidized.
Chemistry 122 Mr. McIsaac
FINAL EXAM - Sample
Page 6 of 7
II. Problems. Be sure to show all work completely and properly. Do all work on your own paper.
1.
Draw the complete or condensed structure of the following organic molecules. (1 point each)
a. 4-methyl-2-pentene
g. ethylmethylamine
l. 3,5,5-trichloro-1-phenyl-2-pentanone
b. 4-ethyl-5-methyl-2-hexyne
h. butanal
m. butanamide
c. 1,3-dibromo-1-butanol
i. butanone
n. 2,3-dibromo-2-pentene
d. propyl pentanoate
j. 1,3-difluorocyclohexane
o. 1,4-dimethylbenzene
e. methylpentanamide
k. 4-hydroxy-3-ethylpentanal
p. 3,5-dichoro-3-methylcyclopentene
f. diethylamine
2.
What is the total energy needed to convert 56.5 g of ice at -16.50°C to water at 49.7°C?
3.
Assuming 100% efficiency, what mass of methane would be need to be burned to heat 5.69 L of water from 31.5°C to
69.3°C? (Hint: calorimetry with water gaining heat/temperature and methane losing heat/enthalpy.)
4.
The standard molar enthalpy of formation (Hf°) of barium carbonate from its elements is -1216.3 kJ/mol. Show how this
information can also be communicated in three other standard methods.
a. Balanced chemical equation (formation of BaCO3(s) from its three elements) using the ÄH notation at side.
b. Balanced thermochemical equation including the energy as part of the equation.
c. Potential energy diagram.
d. Explain why it would be correct to say there is greater thermal stability in the above matter in the form of the product
than in the form of the reactants (1 - 2 sentences).
e. Use the Hess’s Law method to solve for ÄHr° for the following reaction:
4 CO2(g) + 6 H2O(g) —> 2 C2H6(g) + 7 O2(g)
Given:
2 CO2(g) + 2 H2O(g) —> C2H4(g) + 3 O2(g)
ÄHr° = 1323 kJ
ÄHr° = 137 kJ
C2H6(g) —> C2H4(g) + H2(g)
ÄHr° = -484 kJ
2 H2(g) + O2(g) —> 2 H2O(g)
5.
Use the standard molar enthalpies of formation method to determine the molar enthalpy of reaction (Hr°) for sulfur dioxide.
(Hint: first find the ÄHr° for the reaction using the “ÓHf°” method, then an additional molar calculation to get Hr°.)
2 ZnO(s) + 2 SO2(g) ——> 2 ZnS(s) + 3 O2(g)
6.
What quantity of energy can be obtained by burning 465 g of octane? (Hint: first use the “ÓHf°” method to find Hr° for
octane; then use this Hr° in the ÄHr° = nHr°)
2 C8H18(l) + 25 O2(g) —> 16 CO2(g) + 18 H2O(g)
8.
Ammonia (a gas at SATP) has an exothermic molar enthalpy of formation (from its constituent elements nitrogen and
hydrogen), and at SATP conditions, the equilibrium favors the product in this formation reaction.
a. Write the balanced equilibrium equation, being sure to include: states of matter, appropriate equilibrium arrows, energy
on the proper side, percent yield.
b. State the effect of each of the following on the equilibrium reaction (i.e. direction of shift):
1. increase the pressure 2. decrease the temperature 3. remove some of the NH3(g)
4. increase the volume of the reaction container
c. Write the expression/law for the equilibrium constant.
d. Based on the following measurements of concentrations at equilibrium, calculate the value of the equilibrium constant.
0.0084 mol/L N2(g); 0.53 mol/L H2(g); 0.28 mol/L NH3(g)
7.
Acetic acid is a weak acid with a 1.5% ionization. A sample solution is known to have a [H+(aq)] = 4.48 x 10-3 M.
a. Show method and calculate each of the following (in any order): [OH-(aq)], pH, pOH
b. Write the balanced ionization equation, with % ionization above equilibrium expression.
c. Fill in theoretical (100%) concentrations above and actual equilibrium concentrations below.
d. If the sample solution has a volume of 2.50 x 102 mL, calculate the mass of acetic acid present. [Hint: Use the standard
solution concentration formula to solve for m.]
8.
For the following reaction: Cd(s) + AuPO4(aq) —> Au(s) + Cd3(PO4)2(aq)
a. Copy the reaction and label oxidation numbers above all elements in reactants and products.
b. Draw and label with LEO and GER arrows above and below.
c. Specifically list/identify the OA and RA.
d. Identify and write the LEO/oxidation and GER/reduction half reactions.
e. Balance and write the net ionic reaction.
Chemistry 122 Mr. McIsaac
FINAL EXAM - Sample
REFERENCE MATERIAL
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Periodic Table c/w atomic masses.......................................................... Periodic Table handout
Specific Heat Capacities. ......................................................... Back of Periodic Table handout
Molar Enthalpies of Combustion (Hc). ........................................................... Textbook p. 517
Molar Enthalpies of Fusion and Vapourization............................................... Textbook p. 522
Standard Molar Enthalpies of Formation (Hf°). ............................................... Textbook p. 530
Standard Molar Concentrations of Strong Acids and Bases ... Back of Periodic Table handout
Solubility Table ............................................................................................... Textbook p. 344
Table of Common Polyatomic Ions ....... Top of Periodic Table handout; also Textbook p. 257
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