UNIVERSITY OF VICTORIA
FINAL EXAMINATION
CHEMISTRY 102 Fundamentals of Chemistry II
Thursday APRIL 11, 2013
Sections: A01, A02, A03
CRN 22735, 22736, 21284
Instructors: R. Lipson, S.
Briggs, A. Brolo
Duration: 3 hours
This exam has a total of 17 pages + DATA sheet (inside) + optical sense (bubble) sheet (separate)
Students must count the number of pages in this examination paper before starting to write the exam.
Report any discrepancy immediately to one of the instructors in the room.
DISPLAY YOUR STUDENT ID CARD ON THE TOP OF YOUR DESK NOW
Answer all questions on the bubble sheet provided. This exam consists entirely of multiple
choice questions. There are 65 multiple choice questions worth 2 marks each. TOTAL MARKS
AVAILABLE = 130
This question paper contains enough blank space for working out the questions. No other paper is permitted.
The answers must be coded on the optical sense form (bubble sheet) using a SOFT PENCIL.
PRINT and shade in only your last name, first name, and the last 7 digits of your
student ID number on the bubble sheet. i.e. Omit the leading V0.
Do NOT include any information about the course, section or date on the bubble sheet.
Hand in only the bubble sheet at the end of the exam period (3 hours).
The basic Sharp EL510 calculator is the only one approved for use in Chemistry 102.
It is a University Calendar regulation that no student may arrive at the exam after the
first half hour and no student may leave the exam in the first half hour.
If you finish your exam before 2¾ hours have elapsed then you may hand in your
bubble sheet and leave. We ask that students not leave (i.e. that students remain seated)
during the last 15 minutes of the exam so that everyone remaining may finish their
exams without noise or disturbance.
DO NOT BEGIN UNTIL TOLD TO DO SO BY THE INVIGILATOR
Chem 102, Final Exam, April 2013
Page 2 of 17
This exam consists entirely of multiple choice questions and is worth 130 marks. There are two marks per
question. The answers for the 65 questions must be coded on the optical sense form (bubble sheet) using a
SOFT PENCIL.
Select the BEST response for each question below.
1. An evacuated 2.00 liter flask weighs 418.00 g. When filled with an “unknown” gaseous element at 1 atm
pressure and 298K the flask plus contents is found to weigh 421.27g. What is the identity of the
“unknown” gas?
A. N2
B. Ne
C. Ar
D. Kr
E. F2
2.
Charles’s law examines the relationship between volume and temperature. What is one important
observation that results from an extrapolation of volume vs. temperature measurements for different gases?
A. All the extrapolated curves intersect at one temperature, corresponding to 0°C.
B. All the extrapolated curves intersect at one temperature, corresponding to 273.15°C.
C. All the extrapolated curves intersect at one temperature, corresponding to 0 K.
D. All the extrapolated curves intersect at one temperature, corresponding to 273.15 K.
E. All the extrapolated curves intersect at one temperature, corresponding to 0 °F.
3.
A 0.0126 mole sample of neon gas occupies 3.00 L at 122K. What pressure (in atm) does it exert?
A. 0.0210
4.
5.
B. 0.0420
C. 0.136
D. 0.0126
E. 42.0
Potassium chlorate decomposes when heated giving potassium chloride and oxygen.
2 KClO3 (s) → 2 KCl (s) + 3 O2 (g)
A test-tube holding 0.715 mol of KClO3 is heated and reaction goes to completion. What volume of
oxygen in liters will be evolved if it is collected at a pressure of 1.04 atm and a temperature of 13.2 oC?
A. 16.15
B. 48.44
D. 24.23
E. 2.455
C. 1.121
Consider the apparatus shown in the drawing below. When the black stopcock between the two
containers is opened and the gases are allowed to mix, what is the partial pressure of N2 after mixing?
N2
2.5 L
2.0 atm
25 oC
A. 1.3 atm
B. 2.5 atm
C. 0.77 atm
O2
4.0 L
3.0 atm
25 oC
D. 5.2 atm
E. 3.2 atm
Chem 102, Final Exam, April 2013
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6. How is the pressure exerted by hydrogen gas affected when some nitrogen is added to the container if the
temperature and volume remain constant?
A. The pressure exerted by H2 gas increases when N2 is added to the container.
B. The pressure exerted by H2 gas changes only if a greater amount of N2 is added to the container.
C. The pressure exerted by H2 gas decreases when N2 is added to the container.
D. The pressure exerted by H2 gas does not change when N2 is added to the container.
E. The pressure exerted by H2 gas decreases by one-half when an equal amount of N2 is added to the
container.
7. In an electrolysis of water experiment, 39.75 mL of H2 gas were collected over water at 60.0°C at a total
pressure of 1.03 atm. The vapour pressure of water at 60.0°C is 19.92 kPa. What mass of H2 was collected?
A. 3.00 mg
B. 2.45 mg
C. 0.572 mg
D. 29.6 µg
E. 4.24 mg
8. Which one of the following gases has the greatest average molecular velocity at 300 K ?
A. argon (Ar)
B. nitrogen (N2)
C. fluorine (F2)
D. neon (Ne)
E. all have the same average molecular velocity.
9. At a temperature of 320 K and a pressure of 16 atm, the molar volume of ammonia (NH3) is about 10%
less than that of an ideal gas under those conditions. The best explanation for this observation is?
A. Intermolecular forces of attraction for NH3 become significant at this temperature and pressure.
B. The volume of an NH3 molecule is smaller than that of an ideal gas molecule.
C. At this temperature, a significant amount of NH3 decomposes to N2 and H2.
D. The volume of an NH3 molecule is significant at this concentration.
E. The average kinetic energy of NH3 is significantly different from that of an ideal gas at this
temperature.
10. Which of the following statements is NOT CORRECT?
A. Absorption of infrared radiation increases the vibrational energy in a molecule.
B. NO is formed by the direct combination of nitrogen and oxygen in internal combustion engines.
C. CO2, N2O and CH4 are all greenhouse gases.
D. O2 and N2 absorb infrared radiation and thereby help maintain the earth’s energy balance.
E. SO2 in the atmosphere is a major cause of acid rain.
Chem 102, Final Exam, April 2013
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11. Which of the following reactions is/are NOT a significant process in the normal set of reactions that
maintain the protective stratospheric ozone layer?
(i) O(g) + O2(g) → O3*(g)
(ii) O2(g) + 2NO(g) → 2NO2(g)
(iii) O3(g) + hv → O2(g) + O(g)
A. (i)
B. (ii)
D. (i) and (ii)
E. (ii) and (iii)
C. (iii)
12. Strategies that can help decrease the quantity of sulfur dioxide (SO2) released to the environment
include:
i) Removal of sulfur from coal before burning the coal.
ii) Injecting powdered limestone into the combustion gases arising from coal-fired power plants.
iii) Relying more heavily on non-hydrocarbon-fuel-generated electricity than we do now.
iv) Mixing coal with calcium sulphate (CaSO4) prior to combustion.
A. All of the above
B. i only
D. iii and iv
E. i, ii and iii
C. ii only
13. Carbon dioxide contributes to global warming by:
A. undergoing photoionization
B. absorbing ultraviolet radiation
C. absorbing incoming radiation from the sun
D. absorbing radiation emitted from the surface of the earth
E. reducing the index of refraction of the atmosphere
14. Which of the following is NOT a consequence of acid rain?
A. Fish in lakes die when the pH is less that about 4.5.
B. Aluminum (as Al3+ ions) leaches into lakes due to high acidity.
C. Mineral plant nutrients such as K+ and Ca2+ become more soluble in acidic conditions and are washed
out of the soil.
D. Limestone sculptures and building stones become damaged by acid rain.
E. Aquatic life suffers because of the higher than usual temperature of the acid rain..
Chem 102, Final Exam, April 2013
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15. Sucrose, C12H22O11, can be metabolized for energy in the body according to the reaction:
C12H22O11 (s) + 12 O2 (g) 12 CO2 (g) + 11 H2O (l)
H° = −5.65 x 103 kJ
How many grams of sucrose must be burned to raise the temperature of 50.0 kg of water by 1.00 °C?
The specific heat capacity of water is 4.184 J g-1 K-1.
A. 12.7 x 103 g
B. 0.0370 g
3
D. 3.45 x 10 g
C. 0.724 g
E. 12.7 g
16. A gas is confined to a cylinder under a moveable piston at constant pressure. When the gas undergoes a
particular chemical reaction, it absorbs 2,500 J of heat from the surroundings and does 7,655 J of work
on the surroundings. What are the values of H (in J) and E (in J) for this process?
A. H = 10155 J,
E = 5155 J
B. H = 2500 J,
E = −5155 J
C. H = 10155 J,
E = 2500 J
D. H = 5155 J,
E = 2500 J
E. H = 2500 J,
E = −7655 J
17. The magnitudes of the enthalpies (heats) of vaporization, fusion, and sublimation are determined by …
A. the density of the substance.
B. the magnitudes of the boiling and melting points of the substance.
C. the strength of the covalent bonds between atoms in each molecule of the substance.
D. the strength of the intermolecular forces of the substance.
E. the heat required to raise the temperature of one mole of the substance by 1.0°C.
18. Under what condition(s) is the enthalpy change of a process equal to the amount of heat transferred into
or out of the system?
(a) temperature is constant
(b) pressure is constant
(c) volume is constant
A. a only
B. b only
C. c only
D. a and b
E. b and c
Chem 102, Final Exam, April 2013
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19. The sublimation of solid carbon dioxide is a spontaneous process at 25oC. Predict the sign (+ , – , or 0)
of ΔGo, ΔHo and ΔSo, respectively, for this process.
A. – , 0, +
B. – , – , –
C. – , +, +
D. 0, +, +
E. – , +, –
20. For which of the following reactions is the enthalpy of reaction equal to the enthalpy of formation of the
product?
A. 3 H(g) + N(g) → NH3(g)
B. 3/2 H2(g) + 1/2 N2(g) → NH3(g)
C. 3 H2(g) + N2(g) → 2 NH3(g)
D. 3 H2(ℓ) + N2(ℓ) → 2 NH3(g)
E. All of the above
21. Given the following reactions
Fe2O3(s) + 3CO(g)  2Fe(s) + 3CO2(g)
3Fe(s) + 4CO2(g)  4CO(g) + Fe3O4(s)
the enthalpy of the reaction of Fe2O3 with CO
3Fe2O3 (s) CO(g)
is __________ kJ.
CO2 (g) 2Fe3O4 (s)
A. -59.0
C. -15.5
B. 40.5
D. -109
ΔH° = -28.0 kJ
ΔH = +12.5 kJ
E. +109
22. Gasoline has a fuel value of 44 kJ g-1 and a density of 0.70 g mL-1. How much energy is contained in a
car’s 55 L tank?
A. 8.8 x 102 kJ
B. 1.7 x 103 kJ
D. 1.7 x 106 kJ
E. 3.5 x 106 kJ
C. 3.5 x 103 kJ
23. How do viscosity and surface tension change as the temperature increases?
A. Viscosity decreases and there is no change in surface tension.
B. Viscosity increases with increasing temperature while surface tension decreases.
C. Viscosity decreases with increasing temperature while surface tension increases.
D. Both viscosity and surface tension increase with increasing temperature.
E. Both viscosity and surface tension decrease with increasing temperature.
Chem 102, Final Exam, April 2013
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24. Molecules of a liquid can pass into the vapour phase only if the …
A. the liquid has little surface tension.
B. vapour pressure of the liquid is high.
C. molecules have sufficient kinetic energy to overcome the intermolecular forces in the liquid.
D. temperature of the liquid is near its boiling point.
E. intermolecular forces are weak.
25. According to the phase diagram given for substance W, which of the following statements is INCORRECT?
A. At the temperature and pressure of point 1, substance W exists as a three-phase equilibrium system.
B. At the temperature of point 2, a pressure of 500 torr is sufficient to liquify gaseous W.
C. If the W(ℓ)  W(g) system is maintained at the temperature of point 3 while pressure is decreased,
more W will vaporize.
D. If liquid W is maintained at the pressure of point 4 while the temperature is increased to 80 °C, the
liquid will vaporize.
E. For W the critical temperature and critical pressure are approx. 43 °C and 2000 torr; respectively.
26. Using the standard enthalpies of formation of methane, water and carbon dioxide given on the DATA
sheet, determine the enthalpy of reaction (ΔH°rxn) in kJ for the production of 1 mole of methane
according to the chemical equation shown.
CO2(g) + 2H2O(l)
CH4(g) + 2O2(g)
A. 232
B. 802.3
C. 890.4
D. 9558
E. 634
Chem 102, Final Exam, April 2013
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27. Which statement is TRUE for a reaction that has Kc = 2.43 × 10–12?
A. Increasing the temperature will not change the value of Kc.
B. There are significant concentrations of reactants and products at equilibrium.
C. The reaction proceeds hardly at all toward completion.
D. The reaction proceeds nearly all the way toward completion.
E. The reaction is endothermic.
28. Given the following hypothetical reaction:
2 A (s) + x B (g)
3 C (g)
KP = 0.0105
and
Kc = 0.45 at 523 Kelvins
What is the value of the stoichiometric coefficient x ?
A. 1
B. 2
C. 3
D. 4
E. 5
29. Consider the following reaction, the decomposition of ammonium hydrogen sulfide:
NH4HS(s)  NH3(g) + H2S(g) for which Kp = 0.108 at 25 oC
A 2.3 g sample of NH4HS(s) is placed in a 1.00 L flask. What will be the total gas pressure when
equilibrium is reached?
A. 0.329 atm
B. 0.657 atm
C. 0.486 atm
D. 0.164 atm
E. 0.786 atm
30. At a certain temperature, the value of the equilibrium constant for the following reaction is Kc = 100.
N2 (g) + 2 O2 (g)
2 NO2 (g)
What is the equilibrium constant for the following reaction?
NO2 (g)
½N2 (g) + O2 (g)
A. 1.0
B. 10
C. 10000
D. 0.1
E. 0.10
Chem 102, Final Exam, April 2013
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31. Consider the following reaction:
N2O4(g)  2NO2(g)
A flask is charged with 6.000 atm of N2O4(g) and 4.000 atm of NO2(g) at 25 oC. After equilibrium is
reached the partial pressure of NO2 is 1.536 atm. Calculate Kp for the reaction.
A. 0.326
B. 0.212
C. 0.278
D. 0.215
E. 0.181
32. An equilibrium mixture of CO, O2, and CO2 at a certain temperature has
[CO2] = 0.0010M and [O2] = 0.0015M. At this temperature the equilibrium
constant Kc = 1.4 ×102.
2CO (g) + O2 (g)
2CO2 (g)
What is the equilibrium concentration of CO?
A. 4.8 × 10–6 M
B. 2.2 × 10–3 M
C. 4.6 × 10–4 M
D. 6.9 × 10–2 M
E. 0.22 M
33. Consider the following reaction:
4 HCl (g) + O2 (g)
2 Cl2 (g)
+ 2 H2O (g)
Kc = 0.063 at 400 K
If the reaction quotient, Q, is 0.100, which of the following statements is FALSE?
A. [HCl] will increase as the reaction approaches equilibrium.
B. [O2] will increase as the reaction approaches equilibrium.
C. [Cl2] will decrease as the reaction approaches equilibrium.
D. [H2O] will increase as the reaction approaches equilibrium.
E. [H2O] will decrease as the reaction approaches equilibrium.
Chem 102, Final Exam, April 2013
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34. At which of the following locations will water boil at the highest temperature?
A. By the ocean at Cadboro Bay beach near UVic.
B. On top of Mt Douglas in the northern part of Victoria near UVic.
C. On top of Mt Everest in the Himalaya.
D. The boiling temperature of water does not depend on the location.
E. It is impossible to estimate this without a calibrated thermometer.
35. How much heat (in kJ) is required to convert 10.0 g water at 25.0 °C into water vapour at the normal
boiling point? (ΔHvap (H2O) is 40.68 kJ mol−1)
A. 3.14
B. 22.6
C. 25.7
D. 410
E. 19.4
36. Which of the following statements is NOT CORRECT?
A. A reaction at equilibrium will shift its equilibrium position if the concentrations of products are
increased.
B. If one starts a reaction with a higher concentration of one reactant, Keq is unaffected.
C. In an equilibrium reaction, the reverse reaction begins as soon as some product is formed.
D. If a catalyst is added, the amount of product present at equilibrium can be increased.
E. If an inert gas is added to a gas reaction at equilibrium, the equilibrium is not affected.
37. The reaction below is at equilibrium. You want to apply le Châtelier’s principle to produce a higher
quantity of product gases. Which change will accomplish this effect?
CO2(g) + 2H2O(l)
CH4(g) + 2O2(g)
A. Increase the pressure on the system.
B. Add a catalyst to the reaction.
C. Remove some water.
D. Increase the volume of the system.
E. Cool the system.
38. Which ONE of the following pairs has the member with the greater molar entropy listed first?
A. HCl(l), HCl(g)
B. Sr(s), Mg(s)
C. CH3OH(l), C2H5OH(l)
D. Fe(s), FeCl2(s)
E. BaO(s), Ba(OH)2(s)
Chem 102, Final Exam, April 2013
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39. Component of air
Mole Fraction
nitrogen
0.781
oxygen
0.209
argon
0.010
What is the partial pressure of nitrogen (in torr) in the atmosphere when the atmospheric pressure is 760
torr?
A. 7.6
B. 159
C. 973
D. 594
E. 662
40. Consider the following reaction.
CO2(g) + 2H2O(l)
CH4(g) + 2O2(g)
Predict the change in entropy (ΔSsys) for the above reaction:
A. approximately zero
B. negative
C. positive
D. There’s not enough information to make an estimate.
E. It depends on ΔHsys.
41. For all of the following reactions both ∆G° and ∆H° are negative. For which reactions is ∆G° more
negative than ∆H°? (You do not need thermochemical data to answer this question.)
(i) SO2(g) + SrO(s) → SrSO3(s)
(ii) N2F4(g) → 2 NF2(g)
(iii) 2PbS(s) + 3O2(g) → 2 PbO(s) + 2 SO2(g)
A. i
B. ii
C. iii
D. i & iii
E. ii & iii
42. A certain chemical reaction at 25 °C has ΔH° = −19.5 kJ mol-1 and ΔS° = −42.7 J K−1 mol-1. Which one
of the following statements about this reaction is FALSE? (Assume that ΔH and ΔS do not change much
with temperature.)
A. The reaction leads to a decrease in the entropy of the system.
B. ΔG° at 298 K is positive.
C. The reaction is spontaneous at standard conditions and 25 °C.
D. The reaction is exothermic.
E. The equilibrium constant is greater than 1.0 when the reaction is carried out under standard
conditions.
Chem 102, Final Exam, April 2013
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43. The value of ΔG° for the following reaction is -2745 kJ. Use this value and the information on the Data
Sheet to calculate the standard free energy of formation, ΔG°f, of C4H10(g) in kJ mol-1.
C4H10(g) +
13
O2(g)
2
4CO2(g) + 5 H2O(l)
A. 24.4
B. −258.
D. −175
E. −18.3
C. −33.0
44. For a reaction with a negative ∆G° value, which of the following statements is/are FALSE?
i. The equilibrium constant K is greater than one
ii. The reaction is spontaneous when all the reactants and products are in their standard states
iii. The reaction is always exothermic
iv. The entropy change for the universe is positive.
A. I
B. ii
C. iii
D. iv
E. i & ii
45. The standard free energy change (∆G°) for the reaction of ammonia with water is 29.05 kJ mol-1 at 25
°C.
NH3(aq) + H2O(ℓ)
NH4+(aq) + OH-(aq)
What is the value of ∆G ( in kJ mol-1) when the concentrations of NH3(aq) = 0.10 M,
NH4+(aq) = 1.0 x 10-3 M, and OH-(aq) = 1.0 x 10-3 M?
46.
A. 0.53
B. 57.6
D. 2.36
E. 26.6
C. -28.5
The following data were collected for the reaction SO2(g) + 2 H2(g) → S(s) + 2 H2O(g).
Experiment No.
1
2
3
[SO2], in mol L–1
0.004
0.008
0.008
What is the rate equation for the reaction?
A. Rate = k [SO2 ]
B. Rate = k [H2]
C. Rate = k [SO2 ]2 [H2]
D. Rate = k [SO2 ][H2]
E. Rate = k [SO2 ]2 [H2]2
[H2], in mol L–1
0.002
0.002
0.004
Rate, in mol L–1 min–1
9.0 x10–7
1.8 x 10–6
3.6 x 10–6
Chem 102, Final Exam, April 2013
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47. For the reaction: A + B B2A, doubling [A] doubles the rate of the reaction. However, tripling [B]
increases the rate 9 times. What is the correct rate law expression?
A. Rate = k [A][B]
B. Rate = k [A][B]2
D. Rate = k [A]2[B]
E. Rate = k [A]2[B]2
C. Rate = k [A]½[B]
48. In the nuclear industry, workers use a rule of thumb that the radioactivity from any sample will be
harmless after 10 half-lives. What fraction of a radioactive sample remains after this time?
(Radioactive decays obey first-order kinetics.)
A. 0.10
49.
B. 0.01
C. 0.001
D. 0.05
E. 0.03
For some reaction involving carbon
monoxide (CO), the plot at the right
indicates
A. the reaction order for CO is one.
B. the reaction order for CO is two.
C. the reaction order for CO is zero.
D. the rate constant varies with
temperature.
E. the instantaneous rates at various
times.
50. The radioactive isotope U-238 decays by first order kinetics. For this decay the rate constant k has the
value 0.154 My-1. ( 1 My = 1 megayear = 1 million years) How long will it take for 25% of a given
sample of U-238 to decay? (i.e. How long until the radioactivity decreases to 75% of its original value?)
A. 0.023 My
B. 1.9 My
C. 3.9 My
D. 9.0 My
E. 0.81 My
51. The rate law for the reaction 2 NO2(g) → N2O4(g) is rate = k [NO2]2. Which of the following changes
will change the value of the rate constant, k?
A. The pressure of NO2 is doubled.
B. The value of k will never change, because it is a constant.
C. The volume of the container is doubled.
D. The temperature is decreased.
E. Doubling the concentration of NO2(g).
Chem 102, Final Exam, April 2013
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52. How does a catalyst increase the rate of a reaction?
A. by lowering the H for the reaction
B. by lowering the activation energy
C. by lowering the product energy
D. by lowering the reactant energy
E. by raising the product energy
53. The main harmful effect of the presence of large amounts of biodegradable organic matter in a lake or
pond is:
A. The organic matter causes the water to become murky.
B. Decay of the organic matter causes the water to become depleted in dissolved oxygen.
C. The organic matter blocks sunlight needed by aquatic plants.
D. The organic matter causes warming of the water as it decomposes.
E. The organic matter settles to the bottom, displacing bottom-dwelling species.
54. It is often necessary to remove some of the hardness of water to be used domestically because of the
following problems;
(i) Build-up of CaO concentrations in the water.
(ii) Formation of scale deposits in kettles and water pipes.
(iii) Hard water is unhealthful to drink.
(iv) Hard water leads to precipitation of ‘soap scum’ when washing.
(v) CaCO3 has a bad taste.
A. ii and iii
B. All of the above
C. i and v
D. i, ii, and iv
E. ii and iv
55. Ozone in the upper atmosphere is destroyed by the following mechanism:
Cl(g) + O3(g) →
ClO(g) + O2(g)
ClO(g) + O(g) → Cl(g) + O2(g)
(slow)
(fast)
The following statements may be deduced from the mechanism. Which one is INCORRECT?
A. The overall chemical equation predicted by this mechanism is O3(g) + O(g) → 2O2(g)
B. ClO is an intermediate in this mechanism.
C. The overall rate law is Rate = k[O3]
D. The activation energy of the first step is greater than the activation energy of the second step.
E. The slow step is bimolecular.
Chem 102, Final Exam, April 2013
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56. Which of the following statements about fresh water is INCORRECT?
A. Nitrogen containing and phosphorus containing compounds contribute to water pollution by causing
excessive growth of aquatic plants, leading to eutrophication.
B. Hard water has an excess of Cl− ions.
C. Disinfection of drinking water can be accomplished by treatment with ozone.
D. One of the drawbacks of chlorination is production of trihalomethane molecules.
E. Municipal water treatment uses Al2(SO4)3 and CaO to remove suspended small particles.
57. In a calibration experiment the heat capacity of a constant volume bomb calorimeter was measured to be
C = 6.52 kJ °C−1. In a second experiment in the same calorimeter, 0.0208 mol of diamond (pure carbon)
was burned and the temperature increased from 20.00 °C to 21.26°C. Calculate ΔE for this combustion
(in kJ mol−1).
A. −74.5
B. 0.171
C. −395
D. +395
E. 8.22
58. For the following elementary reaction:
A + B → C
consider these three different sets of conditions.
(i) 1 mol of A and 1 mol of B in a 1.0 L container.
(ii) 2 mol of A and 2 mol of B in a 2.0 L container.
(iii) 0.2 mol of A and 0.2 mol of b in a 0.1 L container.
For which set of conditions is the reaction rate the greatest (i.e. fastest reaction)?
A. (i)
B. (ii)
D. (i) and (ii)
E. all at same rate
C. (iii)
59. What are the units of the rate constant for a second order elementary reaction of the form
2A → products ?
A. M s-1
B. M s
D. M-1 s
E. s-1
C. M-1 s-1
Chem 102, Final Exam, April 2013
60. The integrated rate law for a zero order reaction A → B
The half-life of such a reaction is given by t1/2 =
A.
B.
C.
D.
E.
Page 16 of 17
is: [A] ─ [A]o = -kt
[A]o/2k
(ln2)/k
1/k[A]o
0.693/k
[A]o/k
61. The equilibrium constant KP for the reaction
2CO(g) +
O2(g) ⇋ 2CO2(g)
is 1.4 x 1090 at 25ºC. Given this enormous value, why doesn’t CO convert totally to CO2 in the
troposphere (i.e. at ground level)?
A.
B.
C.
D.
E.
The reaction can’t work without a catalyst.
The equilibrium lies to the left.
Sunlight rapidly converts CO2 back to CO.
Entropy favours the reactants.
The activation energy for the reaction is too high.
62. Which of the following statements best corresponds to fact?
A.
B.
C.
D.
Both photoionization and photodissociation occur in the stratosphere.
Neither photoionization nor photodissociation occurs in the mesosphere.
Photoionization occurs in the troposphere and photodissociation in the stratosphere.
Photoionization occurs in the thermosphere and photodissociation in the
troposphere.
E. Photodissociation and photoionization occur mainly in the in the troposphere.
63. Why are chlorofluorocarbons (CFCs) so damaging to the ozone layer when they are such stable
molecules?
A. CFCs are very light molecules that rapidly diffuse into the upper atmosphere and block the radiation
that causes the formation of ozone.
B. CFCs contain a double bond that reacts with ozone, resulting in the destruction of the ozone.
C. The radiation in the stratosphere dissociates CFCs to produce chlorine atoms that catalytically destroy
ozone.
D. CFCs are greenhouse gases that raise the temperature above the dissociation temperature of ozone.
E. CFCs do not damage the ozone.
Chem 102, Final Exam, April 2013
Page 17 of 17
64. When baking soda is heated it decomposes according to the following reaction:
2NaHCO3(s)
Na2CO3(s)
+ CO2(g) + H2O(g)
If sufficient baking soda is placed in a container and heated to 90C, the total pressure in the container is
measured to be 0.5451 atmospheres. What is the value of Kp for this reaction?
A. 0.07428
B. 0.2973
C. 0.4228
D. 1.091
E. 0.5451
65. Which of the following statements is NOT CORRECT?
A. Visible and ultraviolet radiation wavelengths reach the earth’s surface and this energy is re-emitted
by the earth as infrared radiation (heat).
B. Absorption of infrared radiation decreases the vibrational energy in a molecule.
C. Atmospheric concentrations of CO2 in the earth’s past can be determined by analysing air bubbles
trapped in glaciers.
D. CO2, CH4, and water vapour are all greenhouse gases.
E. Unburned hydrocarbons in the troposphere are a significant part of the problem of
photochemical smog.
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