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AP Chem
Final
1. Which of the following gases deviates the most from ideal behavior?
A. Ne B. HCl C. Ne D. CH4 E. O2
2. Which of the following solutions is most ideal (most closely follows Raoult’s Law)?
A. C6H14 and H2O
B. CH3CH2CH2OH and H2O
C. CH3CH2CH2OH and C6H14
D. C5H12 and C9H20
E. H2O and H2SO4
3. Which of the following processes involves the breaking of covalent bonds?
A. Sublimation of I2
B. Sublimation of CO2
C. NaCl(s) = NaCl(l)
D. C(diamond) = C(g)
E. Melting of Fe
4. When solid KNO3 is added to water at 25C it dissolves and the temperature of the
solution decreases. Which of the following is true?
A.
B.
C.
D.
E.
Delta H
+
+
+
-
Delta S
+
0
+
Questions 5-7 refer to the following:
A.
B.
C.
D.
E.
1s22s22p6
1s22s22p63s2
1s22s22p63s23p4
1s22s22p63s23p6
1s22s22p63s23p64s2
5. The ground state configuration of a paramagnetic element.
6. The ground state configuration of both the potassium and the chloride ion.
7. An atom that has this ground state configuration will have the smallest radius of those
listed above.
Questions 8-11 refer to the following:
A. CO2 B. H2O C. SO2 D. NO2 E. O2
8. In this molecule oxygen forms sp3 hybrid orbitals
9. This molecule contains one unpaired electron.
10. This molecule contains no pi bond.
11. This molecule has the highest boiling point of the five.
12. A pure sample of KClO3 is found to contain 71 grams of chlorine. What is the mass
of the sample?
A. 122g B. 170g C. 209g D. 245g E. 293g
13. Which of the following sets of quantum numbers describes the highest energy
valence electron in an aluminum atom?
A. 2,0,0,1/2
B. 2,1,0,1/2
C. 3,0,0,1/2
D. 3,0,1,1/2
E. 3,1,1,1/2
14. The boiling point of water is known to be lower at high elevations. This is because
A. hydrogen bonds are weaker at high altitudes.
B. the equilibrium vapor pressure is lower due to the higher atmospheric pressure.
C. the vapor pressure of water is higher at high elevations.
D. the equilibrium vapor pressure equals the atmospheric pressure at a lower
temperature.
E. water molecules have a higher average kinetic energy due to the lower atmospheric
pressure.
15. When the following half-reaction is balanced, what is the coefficient for H+?
A. 3 B. 4 C. 5 D. 8 E. 10
16. A student examined 2.0 moles of an unknown compound and found that the
compound contained 48g C, 64g O, and 8g H. Which of the following could be the
molecular formula of the compound?
A. CH2O
B. CH2OH
C. CH3COOH
D. CH3CO
E. C2H5OH
17. For the following nuclear reaction what is the missing reactant?
________ + 1n = 7Li + 4He
A. 9Be B. 9B C. 10Be D. 10B E. 11B
18. 2FeS + 3O2 = 2FeO + 2SO2
If this reaction occurs at STP, approximately how many liters of O2 is required to produce
70g of FeO?
A. 22 B. 33 C. 44 D. 55 E. 66
19. A beaker containing 150ml of .2M Pb(NO3)2 is added to a beaker containing 50ml of
.2M MgCl2. What is the final concentration of Pb2+ ions in the solution?
A. .2M B. .1M C. .05M D. .025M E. .012M
20. One half liter of .2M HCl is added to one half liter of .4M AgNO3. What is the mass
of AgCl produced?
A. 14g B. 28g C. 42g D. 70g E. 84g
21. The first ionization energy for Mg is 730kJ/mol. The third ionization energy is
7700kJ/mol. What is the most likely value for the second ionization energy?
A. 490 B. 1400 C. 4200 D. 7100 E. 8400
22. How many grams of carbon are present in 270 grams of glucose?
A. 12g B. 18g C. 67.5g D. 72g E. 108g
23. Which of the following statements regarding nitrogen and fluorine is not true?
A. Fluorine has greater electronegativity.
B. Fluorine has a greater first ionization energy.
C. Fluorine has more valence electrons.
D. Fluorine has a greater atomic mass.
E. Fluorine has a greater atomic radius.
24. Which of the following regarding elemental nitrogen is not true?
A. It contains one sigma bond.
B. It contains two pi bonds?
C. It has a bond order of three.
D. It has a large dipole moment.
E. It exists as a diatomic gas.
25. The line spectrum of an H atom was examined. The electronic transition from n=1 to
n=3 was found to have a frequency of 2.92X1015Hz. When the same transition occurred
in a He+ ion the frequency was 1.17X1016Hz. Which of the following best accounts for
the difference?
A. Less energy is released by the He+ because of its greater molar mass.
B. More energy is released by the He+ transition because of the greater nuclear charge of
the He+ ion.
C. More energy is released by the He+ transition because the ionic radius of He+ is
greater than the atomic radius of H.
D. Less energy is released by the He+ transition because the ionic radius of He+ is
smaller than the atomic radius of H.
E. Less energy is released by the He+ transition because of the greater nuclear charge of
the He+ ion.
26. 2H2O2(l) + S(s) = SO2(g) + 2H2O(g)
Based on the information below, what is delta H for the reaction above?
Substance:
Heat of formation (kJ/mol):
H2O2
-150
SO2
-300
H2O
-250
A. -500 B. -200 C. 200 D. 400 E. 600
27. If a sample of SO2 effuses through a given aperture at rate x which of these gases
will effuse through the same aperture under the same conditions at a rate of 2x.
A. H2 B. O2 C. CO D. He E. CH4
28. A sample of an ideal gas is placed in a sealed container of constant volume. If the
temperature of the gas is increased by 30K which of the following values will not
increase?
A. The average speed of the molecules of the gas.
B. The average kinetic energy of the molecules of the gas.
C. The pressure exerted by the gas.
D. The density of the gas.
E. The frequency of collisions between molecules of the gas.
29 and 30 refer to the following:
F2(g) + 2ClO2(g) = 2FClO2(g)
Experiment:
1
2
3
[F2] (M)
.1
.2
.4
[ClO2] (M)
.01
.01
.02
Initial rate of disappearance of F2 (M/s)
1.2X10-3
2.4X10-3
9.6X10-3
29. Based upon the data in the table what is the rate law for the reaction?
A. Rate = k[F2]
B. Rate = k[ClO2]
C. Rate = k[F2][ ClO2]
D. Rate = k[F2]2[ClO2]
E. Rate = k[F2][ ClO2]2
30. What is the initial rate of disappearance of ClO2 in experiment 2 (in M/s)?
A. 1.2X10-3
B. 2.4X10-3
C. 4.8X10-3
D. 7.2X10-3
E. 9.6X10-3
31. Which has the lowest freezing point?
A. 1m sodium acetate
B. 1m sodium sulfate
C. 1m sodium phosphate
D. 1m sodium hydroxide
E. 1m glucose
32-34 refer to the following:
A. free energy
B. lattice energy
C. kinetic energy
D. activation energy
E. ionization energy
32. The maximum energy available for useful work from a reaction.
33. The energy needed to separate the ions in an ionic solid.
34. The energy difference between the transition state and the reactants.
35-38 refer to the following:
A. composed of atoms held together by delocalized electrons.
B. composed of molecules held together by intermolecular dipole-dipole interactions.
C. composed of positive and negative ions held together by electrostatic interactions.
D. composed of macromolecules held together by strong bonds.
E. composed of molecules held together by intermolecular London forces.
35.
36.
37.
38.
Graphite
Ca(s)
CaCO3(s)
SO2(s)
39. A stock solution that is .30M in Na2SO4 is available. How many moles of solid
Na3PO4 must be added to 800mL of this solution to increase the sodium concentration to
.90M?
A. .06 B. .12 C. .08 D. .16 E. .24
40. Which of the following lists the types of radiation in order of increasing penetrating
power.
A. alpha, gamma, beta
B. beta, alpha, gamma
C. alpha, beta, gamma
D. beta, gamma, alpha
E. gamma, beta, alpha
41. If 75% of a sample of tritium decays in 24.6 years what is the half-life of tritium in
years?
A. 24.6 B. 18.4 C. 12.3 D. 6.15 E. 3.07
42. A sample of ideal gas with a volume of 8L at 127C and 775mm Hg is heated until it
expands to a volume of 20L. What is the final temperature if pressure remains constant?
A. 727C B. 318C C. 1000C D. 160C E. 45C
43. Which of the following best explains why a hot air balloon rises?
A. The heating of the air causes the pressure inside the balloon to increase.
B. The cool air outside pushes the balloon higher.
C. The temperature difference between the inside and the outside air causes convection
currents.
D. Hot air has a lower density than cold air.
E. Cooler air diffuses more slowly than the warmer air.
44. Which is true for the melting of sodium chloride?
A. Delta H > 0 and Delta S > 0
B. Delta H = 0 and Delta S > 0
C. Delta H > 0 and Delta S < 0
D. Delta H < 0 and Delta S < 0
E. Delta H < 0 and Delta S > 0
45. A certain reaction is non-spontaneous under standard conditions but becomes
spontaneous at higher temperatures. What conclusions can we draw about the reaction at
standard conditions?
A. Delta H < 0 Delta S > 0 Delta G > 0
B. Delta H > 0 Delta S < 0 Delta G > 0
C. Delta H > 0 Delta S > 0 Delta G > 0
D. Delta H < 0 Delta S < 0 Delta G > 0
E. Delta H > 0 Delta S > 0 Delta G = 0
46-48 refer to the following: A + B = C
The following are possible rate laws for the hypothetical reaction above.
A. Rate = k[A]
B. Rate = k[A]2
C. Rate = k[A][B]
D. Rate = k[A]2[B]
E. Rate = k[A]2[B]2
46. The rate law for a first order reaction.
47. The rate law for a reaction that is second order with respect to B
48. The rate law for a third order reaction.
49-51 refer to the following: A + B = C
The following are possible rate laws for the hypothetical reaction above.
A. Rate = k[A]
B. Rate = k[B]2
C. Rate = k[A][B]
D. Rate = k[A]2[B]
E. Rate = k[A]2[B]2
49. When [A] and [B] are doubled, the initial rate of reaction will increase by a factor of
eight.
50. When [A] and [B] are doubled, the initial rate of reaction will double.
51. When [A] is doubled and [B] is held constant, the initial rate of reaction will not
change.
52-54 refer to the following:
A. Hund’s rule
B. The Heisenberg uncertainty principle
C. The Pauli exclusion principle
D. The de Broglie hypothesis
E. The Bohr model
52. No two electrons in the same atom can have the same set of 4 quantum numbers.
53. Electrons half-fill degenerate orbitals first.
54. It is impossible to know both the position and the momentum of a particle
simultaneously.
55. When sodium chloride is added to a solution of silver nitrate which precipitate will
appear?
A. sodium B. silver C. sodium chloride D. silver chloride E. silver nitrate
56. A substance is dissolved in water, forming a .5 molar solution. If 4 liters of solution
contains 240g of substance what is the molar mass of the substance?
A. 60 B. 120 C. 240 D. 480 E. 640
57. A solution contains equal masses of glucose (mm =180) and toluene (mm=90).
What is the mole fraction of glucose in the solution?
A. .25 B. .33 C. .5 D. .67 E. .75
58. What is the mass of oxygen in 148 grams of calcium hydroxide?
A. 16g B. 24g C. 32g D. 48g E. 64g
59. C3H8 + O2 = CO2 + H2O
If 67L of CO2 is produced at STP what mass of propane burned?
A. 11g B. 22g C. 33g D. 44g E. 55g
60. A sample of a CuSO4 hydrate with a mass of 250g was heated and all the water
removed. The sample was then weighed and found to have a mass of 160g. What is the
formula of the hydrate? (CuSO4. _H2O)
A. 10 B. 7 C. 5 D. 2 E. 1
61. Na + H2O = NaOH + H2
If 1.8g of H2 are produced, then how much Na reacted?
A. 5g B. 10g C. 20g D. 30g E. 40g
62-65 refer to the following:
A. Sr B. Cu C. Na D. Fe E. Am
62.
63.
64.
65.
Gives a red flame test and produces the red color in fireworks.
Can have a +1 and a +2 oxidation state.
Has the largest atomic radius
Has naturally radioactive isotopes used in smoke detectors.
66. Water is an unusual compound in that
A. It forms networks of hydrogen bonds and its solid form is less dense that the liquid.
B. It has an unusually large difference between its melting and boiling points.
C. It dissolves a wide variety of other compounds.
D. It has a very high specific heat and heat of vaporization.
E. all of these
Free Response
1. Use principles of atomic structure, bonding, and/or intermolecular forces to respond to
each of the following. Your responses must include specific information about all
substances referred to in each question.
A. At a pressure of 1 atm. the boiling point of NH3 is 240K and the boiling point of NF3
is 144K.
(i) Identify the intermolecular force(s) in each substance.
(ii) Account for the difference in the boiling points of the two substances.
B. The melting point of KCl is 776C while the melting point of NaCl is 801C.
(i) Identify the type of bonding in each substance.
(ii) Account for the difference in the melting points of the two substances.
C. As shown in the table below, the first ionization energies of Si, P, and Cl show a
trend.
Element:
First Ionization Energy (kJ/mol)
Si
786
P
Cl
1012
1251
(i)
(ii)
For each of the three elements, identify the quantum level (e.g., n=1, n=2 etc.)
of the valence electrons in the atom.
Explain the reasons for the trend in first ionization energies.
D. A certain element has two stable isotopes. The mass of one isotope is 62.93 amu and
the mass of the other is 64.93 amu.
(i) Identify the element. Justify your answer.
(ii) Which isotope is more abundant? Justify your answer.
2. Answer the following questions that relate to chemical bonding.
A. Draw Lewis structures for CF4, PF5, and SF6
B. On the basis of the Lewis structures you drew, answer the following question about
the molecule indicated.
(i) What is the F-C-F bond angle in CF4?
(ii) What is the hybridization of the valence orbitals in P in PF5?
(iii) What is the geometric shape formed by the atoms in SF6?
C. Two Lewis structures can be drawn for the OPF3 molecule. Draw both and answer
the following questions:
(i) How many sigma and how many pi bonds are in each structure?
(ii) Which one of the structures best represents a molecule of OPF3? Justify your answer
in terms of formal charge.
3. Answer the following questions about a pure compound that contains only carbon,
hydrogen, and oxygen.
A. A 0.7548g sample of the compound burns in O2 to produce 1.9601g CO2 and .3370g
of H2O.
(i) Calculate the individual masses of C, H, and O in the .7549g sample.
(ii) Determine the empirical formula of the compound.
B. A .5246g sample of the compound was dissolved in 10.0012g of lauric acid and the
freezing point of the lauric acid was lowered by 1.68C. The value of Kf for lauric acid is
3.90C/m. Assume the compound does not dissociate in lauric acid.
(i) Calculate the molality of the compound dissolved in lauric acid.
(ii) Calculate the molar mass of the compound.
C. Without doing any calculations, explain how to determine the molecular mass of the
compound based on the answers above.
4. Answer the following questions related to the kinetics of chemical reactions.
I- + ClO- = IO- + Cl- (catalyzed by OH- ion)
Iodide ion is oxidized to hypochlorite ion in basic solution according to the equation
above. Three initial-rate experiments were conducted; the results are shown in the
following table.
Experiment:
1
2
3
[I-]
.017
.052
.016
[ClO-]
.015
.015
.061
Initial rate of formation of IO- (mol L-1 s-1)
.156
.476
.596
A. Determine the order of the reaction with respect to each reactant listed below. Show
your work.
(i) I(ii) ClOB. For the reaction,
(i) Write the rate law that is consistent with the calculations in part (a);
(ii) Calculate the value of the specific rate constant, k, and specify units.
The catalyzed decomposition of hydrogen peroxide, H2O2(aq), is represented by the
following equation.
2H2O2 = 2H2O + O2 (catalyzed)
The kinetics of the decomposition reaction were studied and the analysis of the results
show that it is a first order reaction. Some of the experimental data is given below.
[H2O2] (M)
1
.78
.61
T (minutes)
0.0
5.0
10.0
C. During the analysis the graph that appears on the board was produced.
(i) Label the vertical axis of the graph.
(ii) What are the units of the rate constant?
(iii) What would the graph of the line that represents the plot of the uncatalyzed first
order decomposition look like compared to the catalyzed.