Download Semester 2 Final Exam

South Pasadena • Honors Chemistry
Name
Semester 2 Final Exam
Period
PART



A
•
MULTIPLE CHOICE
Date
(PRACTICE)
You may use a pencil, eraser, and scientific calculator to complete the test.
You will be given a periodic table. Useful formulas and the solubility rules are listed at the end of the test.
No other resources are allowed.
Please transfer your answers for Multiple Choice questions onto the Answer Document. Work for these
questions will not be graded.
1. When water freezes at 0°C, which of the following
is true of the process?
I. The process is endothermic.
II. Molecular attractions are strengthened.
III. The value of q is positive.
(A) II only.
(B) I and III only.
(C) II and III only.
(D) I, II, and III.
2. Which of the following is true for an endothermic
process?
(A) A + heat → B
(B) Heat is released.
(C) The energy of the products is lower than the
energy of the reactants.
(D) The value of c is positive.
3. In which of the following processes is heat
absorbed?
(A) Dissolving calcium chloride, CaCl2(s), in
water gets hot
(B) Combustion of propane, C3H8 (g)
(C) Vaporizing of methyl alcohol, CH3OH (ℓ),
in the hand boiler
(D) Cooling of He (g) in a balloon in the freezer
4. How much heat is required to heat 100 grams of
water from 20.0 °C to 50.0 °C?
(c of water = 1.0 cal/g·°C)
(A) 2000 cal
(B) 3000 cal
(C) 5000 cal
(D) 7000 cal
5. As a block of aluminum is heated with 600 J of
energy, its temperature increases from 10°C to
47°C. What is the mass of this block?
(c of Al = 0.900 J/g·°C)
(A) 0.055 g
(B) 14.6 g
(C) 18.0 g
(D) 33.3 g
6. The units for heat are:
(A) J
(B) J/g
(C) J/g·°C
(D) J/°C
7. 20.0 gram samples of each of the following metals
are originally at 10°C. They are heated evenly for
ten minutes. Which metal will have the highest
temperature at the end?
(A) Aluminum (c = 0.900 J/g·°C)
(B) Copper
(c = 0.386 J/g·°C)
(C) Gold
(c = 0.126 J/g·°C)
(D) They will all end up at the same temperature.
8. 5000 J of heat is applied to 50-g samples of three
liquids at their boiling points. Which substance
will have the MOST liquid remaining?
(A) Ammonia (∆Hvap = 1370 J/g)
(B) Ethanol
(∆Hvap = 840 J/g)
(C) Water
(∆Hvap = 2260 J/g)
(D) All of the liquids would have the same amount
of liquid after heating.
9. When water vapor undergoes condensation, which
of the following does NOT change?
(A) The temperature of the sample.
(B) The molecular attractions.
(C) The state of matter.
(D) All of the above change.
Questions 10-12: Use the following information
For water, Cp,ice = 2.10 J/ g·°C, Cp,water = 4.18 J/ g·°C,
Cp,steam = 2.08 J/g·°C, ∆Hfus = 6.00 kJ/mol,
∆Hvap = 40.7 kJ/mol
14. Photographic film is sometimes kept in the
refrigerator
(A) because cold film results in sharper pictures.
(B) to slow down the chemical reactions on the
film.
(C) to protect the film from light.
(D) because the cold insulates the film.
15. What distance corresponds to the activation energy
for the reaction of X to Y?
A large ice cube is placed in a cup of water at 0°C.
After a few minutes, some of the ice remains.
10. Which of the following equation correctly
describes the melting of the ice?
(A) H2O (ℓ) + heat  H2O (s)
(B) H2O (ℓ)  H2O (s) + heat
(C) H2O (s) + heat  H2O (ℓ)
(D) H2O (s)  H2O (ℓ) + heat
11. Which portion of the heating curve is associated
with the melting of the ice?
Temp
(D)
(A)
(B)
(A) a
(B) b
(C) c
(D) d
16. What is the ∆H for the reaction shown on the
graph?
(C)
Heat
12. What is the final temperature of the water?
(A) Less than 0°C
(B) 0°C
(C) Greater than 0°C
(D) Impossible to predict
▬▬▬▬▬▬▬▬
13. Which one of the following changes will result in
a decreased rate of reaction?
(A) adding a catalyst
(B) heating up the reactants
(C) cutting the reactants into smaller pieces
(D) diluting the reactants
(A) −15 kcal/mol
(B) −5 kcal/mol
(C) +5 kcal/mol
(D) +10 kcal/mol
17. What would cause the change in the kinetic energy
diagrams as shown?

KE
KE
(A) decreasing the temperature
(B) increasing the surface area
(C) addition of a catalyst
(D) increasing the concentration of reactant
Questions 18-19: Refer to the following kinetic energy
graph. Lines A and B represent the average kinetic
energy and the threshold energy, respectively.
A
B
#
21. What is the expression for the equilibrium
constant for the following reaction:
H2 (g) + I2 (s)  2 HI (g)
[H2][I2]
(A) [HI]2
[HI]2
(B) [H ][I ]
2
2
[H2]
(C) [HI]2
[HI]2
(D)
[H2]
22. Which expression represents the equilibrium
constant, Keq, for this equation?
2 NO (g) + O2 (g)  2 NO2 (g)
(A) [NO][O2]
[NO2]
[NO2]2
[NO]2[O2]
(C) [NO]2 + [O ]
2
2
[NO2]
(B)
KE
18. If the temperature of the system is increased, how
will the graph change?
(A) A will increase, while B remains the same.
(B) B will increase, while A remains the same.
(C) Both A and B will increase.
(D) Both A and B will remain the same.
19. If B decreases while A increases, which of the
following may have happened?
I. The reaction mixture was heated.
II. A catalyst was added.
III. The surface area of the reaction mixture
was increased.
(A) I only.
(B) II and III only.
(C) I and II only.
(D) I, II, and III.
▬▬▬▬▬▬▬▬
20. A catalyst is a substance that…
(A) oxidizes undesired waste products.
(B) changes the rate and does not get used up.
(C) lowers the energy of the reactants.
(D) increases the kinetic energy of the molecules.
(D)
[NO2]
[NO] [O2]
23. This reaction takes place in solution:
A 2B
At equilibrium, [A] = 0.1 M and [B] = 0.1 M.
What is the value of the equilibrium constant, Keq?
(A) 0.10
(B) 0.20
(C) 1.0
(D) 10
Questions 24-28: The value of Keq for the following
reaction is 1.5 × 10–9.
heat + H2SO3 (aq)  2 H+ (aq) + SO32– (aq)
24. Which of the following may indicate that
equilibrium has been reached?
I. [H2SO3] = [H+] = [SO32–]
II. Equal moles of H+ and SO32– have been
added.
III. The pH remains constant.
(A) II only.
(B) III only.
(C) I and III only.
(D) I, II, and III.
25. Which of the following is the correct expression
for the equilibrium constant, Keq, for the reaction?
[H2SO3]
(A) [H+][SO 2–]
3
[H2SO3]
(B) [H+]2[SO 2–]
3
+ 2
[H ] [SO32–]
(C)
[H2SO3]
2[H+][SO32–]
(D) [H SO ]
2
3
26. In an equilibrium mixture, [H2SO3] = 0.0015 M,
and [SO32–] = 1.0 × 10–2 M. What is the [H+] in
this mixture?
(A) 1.5 × 10–5 M
(B) 1.0 ×10–4 M
(C) 1.0 × 10–2 M
(D) 2.0 × 10–2 M
27. To a mixture already at equilibrium, which of the
following would have a greater concentration if
H2SO3 (aq) were added?
I. H2SO3
II. H+
III. SO32–
(A) I only.
(B) II only.
(C) II and III only.
(D) I, II, and III
28. Which of the following conditions would produce
the highest [H2SO3]?
(A) pH = 2.0
T = 10°C
(B) pH = 2.0
T = 40°C
(C) pH = 9.0
T = 10°C
(D) pH = 9.0
T = 40°C
▬▬▬▬▬▬▬▬
29. In this equation, N2 (g) + 3 H2 (g) 2 NH3 (g)
increasing the pressure on the total system causes
the equilibrium to shift to produce
(A) more NH3 (g).
(B) more N2 (g) only.
(C) more N2 (g) and H2 (g).
(D) no change in either reactants or products.
30. Which electrons are being placed into orbitals
correctly in a ground state atom?
(A)
(B)
(C)
(D)
31. Iron’s electrons that are farthest from the nucleus
occupy the ___ orbital.
(A) 3p
(B) 3d
(C) 4s
(D) 4p
32. The electron configuration for magnesium is
(A) [Ar] 2s2
(B) [Ne] 3s2
(C) 1s2 2s2 2p2
(D) 1s2 2s2 3s2
33. Which orbital does the highest energy electron
occupy in the Cu atom?
(A) 3d
(B) 4s
(C) 4d
(D) 4p
34. What is the electron configuration for the Ni2+ ion?
(A) [Ar] 3d10
(B) [Ar] 3d8
(C) [Ar] 4s2 3d6
(D) [Ar] 4s2 3d8
35. How many electrons in sulfur are available for
bonding (valence electrons)?
(A) 2
(B) 4
(C) 6
(D) 8
36. How many valence electrons does S2– have?
(A) 4
(B) 6
(C) 8
(D) 18
37. Which family of elements forms 2+ ions?
(A) Alkali metals
(B) Alkaline earth metals
(C) Oxygen family
(D) Noble gases
38. Which trend is observed as the atomic numbers of
Group II, the alkaline earth metals, increase?
(A) Atomic size decreases.
(B) Ionization energy increases.
(C) Metallic properties decrease.
(D) The tendency to lose electrons increases.
39. Which element has the greatest electronegativity
value?
(A) Cl
(B) F
(C) He
(D) O
40. Consider these elements:
P
S
As
List the elements in order of largest to smallest
atomic radius.
(A) P > As > S
(B) S > P > As
(C) As > P > S
(D) P > S > As
41. Which of the following has the smallest atomic
radius?
(A) Si (atomic number 14)
(B) S (atomic number 16)
(C) Se (atomic number 34)
(D) Sr (atomic number 38)
42. Which of the following correctly lists the elements
in increasing ionization energy?
(A) I < Po < Te
(B) I < Te < Po
(C) Po < I < Te
(D) Po < Te < I
43. When a neutral Cl atom becomes a Cl− ion how
does the size change and why?
(A) bigger / less electron-electron repulsion
(B) bigger / more electron-electron repulsion
(C) smaller / less electron-electron repulsion
(D) smaller / more electron-electron repulsion
44. What type of bond is expected to form between N
and O?
(A) covalent
(B) hydrogen
(C) ionic
(D) metallic
45. What type of bond is expected to form between Li
and I?
(A) covalent
(B) hydrogen
(C) ionic
(D) metallic
46. Which formula represents an ionic compound?
(A) CH4
(B) Cl2O
(C) KI
(D) NH3
47. All of the following elements forms covalent
bonds with Br EXCEPT:
(A) C
(B) H
(C) K
(D) O
48. Bonds between which of the following elements is
expected to be most polar?
(A) C–H
(B) N–O
(C) P–F
(D) S–Br
49. Which type of bond is described as “a lattice of
positive ions in a sea of electrons”?
(A) covalent
(B) hydrogen
(C) ionic
(D) metallic
50. The Lewis symbol for C contains ___ dots.
(A) 2
(B) 4
(C) 6
(D) 12
51. The correct Lewis symbol for aluminum is
(A)
(B)
(C)
(D)
2-
52. The Lewis symbol for O contains ___ dots.
(A) 2
(B) 4
(C) 6
(D) 8
53. In the Lewis Structure for ammonia, NH3, how
many lone pairs of electrons does the nitrogen
atom have?
(A) 0
(B) 1
(C) 2
(D) 3
54. Which of the following describes the bonds in a
molecule of ethyne, C2H2?
(A) 1 double bond, 2 single bonds.
(B) 1 triple bond, 2 single bonds.
(C) 2 double bonds, 1 single bond.
(D) 3 single bonds.
55. The total number of dots drawn in the Lewis
structure of nitrogen, N2, is
(A) 5
(B) 10
(C) 14
(D) 16
56. Which one of these molecules is polar?
(A) Cl2
(B) NH3
(C) CO2
(D) CCl4
57. Each of the following describes ionic solids
EXCEPT:
(A) They are formed from metal and non-metal
atoms.
(B) They can conduct electricity when dissolved
in water.
(C) They have a sea of electrons around
positively charged cations.
(D) All of the above describe ionic solids.
58. Properties of metals include:
(A) brittleness
(B) dull surface
(C) poor conductivity
(D) poundable into sheets
59. Which element would be the best conductor?
(A) As
(B) P
(C) S
(D) Sn
64. A temperature of 36.0 °C represents twice as much
kinetic energy as
(A) −119°C
(B) 18°C
(C) 72°C
(D) 115°C
60. Which of the following is paired INCORRECTLY
with the solid it forms?
(A) Bronze – Metallic solid
(B) CaO – Ionic solid
(C) H2O – Molecular solid
(D) P4O10 – Network covalent solid
65. A pressure of 745 mmHg corresponds to
(A) 0.980 atm
(B) 0.566 atm
(C) 1.02 atm
(D) 2.00 atm
61. Water molecules are attracted to each other with
this type of intermolecular force.
(A) Covalent bonding
(B) Dipole-dipole interactions
(C) Hydrogen bonding
(D) London dispersion forces
66. The pressure of the atmosphere at sea level will
support a column of mercury that is
(A) 22.4 mm in height.
(B) 760 mm in height.
(C) 1.0 m in height.
(D) 30.0 m in height.
62. What is true about a sample of gas molecules
according to the Kinetic Molecular Theory?
(A) At a higher pressure, gas molecules collide
against the walls of the container with the
same frequency.
(B) Every gas molecule in a sample travels at the
same speed.
(C) The volume of the gas molecules is
negligible.
(D) There are significant attractions between polar
gas molecules.
67. What Celsius temperature is equivalent to 100
Kelvins?
(A) –173 °C
(B) 0 °C
(C) 273 °C
(D) 373 °C
63. Two balloons are filled to 2.0 L at 20°C. One is
filled with helium gas, while the other is filled
with hydrogen gas. If the pressure exerted by the
gases in the balloons is the same, we can conclude
that:
I. The mass of the gases is the same.
II. The number of molecules of gas in each
balloon is the same.
III. The number of moles of gas in each
balloon is the same.
(A) I only.
(B) II only.
(C) II and III only.
(D) I, II, and III.
68. Which of the following describes STP?
(A) 1 atm and 0 K
(B) 1 torr and 273 K
(C) 760 atm and 273°C
(D) 760 torr and 0°C
69. A rigid cylinder contains a gas. What increases as
the cylinder is heated?
I. The average kinetic energy of the sample.
II. The number of collisions the gas makes
with the walls of the cylinder.
III. The number of gas molecules in the
container.
(A) II only.
(B) I and II only.
(C) I and III only.
(D) I, II, and III.
70. Which of the following graphs describe how the
volume of a gas sample changes when the
temperature is increased at constant pressure?
(A) V
T
(B)
V
T
(C)
V
T
(D)
74. A constant volume of gas at 97.3 kPa and 275 K
undergoes a change in pressure to 104 kPa. What
is the new temperature of the gas?
(A) 225 K
(B) 257 K
(C) 275 K
(D) 294 K
V
T
71. In which of the following is the pressure of a gas
sample the greatest?
(A) V = 1.5 L
T = 20°C
(B) V = 1.5 L
T = 40°C
(C) V = 3.0 L
T = 20°C
(D) V = 3.0 L
T = 40°C
72. If the volume of a gas at 323 K is changed from
780 mL to 620 mL at constant pressure, what will
the new temperature of the gas be?
(A) 257 K
(B) 406 K
(C) 303 K
(D) 381 K
73. A sample of a gas with a volume of 700 mL and
pressure of 1.00 atm is brought to a volume of 200
mL at constant temperature. What is the final
pressure of the gas?
(A) 1.00 atm
(B) 1.40 atm
(C) 0.286 atm
(D) 3.50 atm
75. A gas at 25.0°C and 680 mmHg occupies 345 mL.
What is the volume of the gas at STP?
(A) 283 mL
(B) 306 mL
(C) 336 mL
(D) 421 mL
76. 1.22 L of a gas at 298 K and 750 mmHg
undergoes a change in pressure and temperature to
323 K and 710 mmHg. What is the new volume
of the gas?
(A) 0.800 L
(B) 1.06 L
(C) 1.25 L
(D) 1.40 L
77. What volume will 27.6 g of SO2 occupy at a
pressure of 97.3 kPa and temperature of 38.0°C?
(molar mass SO2 = 64.1 g/mol)
(A) 0.0151 L
(B) 0.733 L
(C) 1.40 L
(D) 11.4 L
78. A 240 mL sample of gas at 100°C and 755 mmHg
is found to have a mass of 1.12 g. What is the
molar mass of the gas?
(A) 34.2 g/mol
(B) 38.5 g/mol
(C) 130 g/mol
(D) 144 g/mol
79. A sample of a gas at STP has a volume of 1.00 L.
How many moles of this gas are contained in this
sample? (R = 0.0821 L atm/mol K)
(A) 0.0446 moles
(B) 0.0821 moles
(C) 1.00 moles
(D) 22.4 moles
Useful Formulas and Constants
K = °C + 273
atm-L
mol-K
m
D=V
R = 0.0821
1 mole = 6.022 × 1023 particles = 22.4 L gas at STP
1 atm = 760 mmHg = 760 torr = 14.7 psi = 101.3 kPa
m
Molar Mass = n
n
M=V
q = m ∙ c ∙ ∆T
q = n · ∆H
nA
PA = n  (Ptotal)
Ptotal = PA + PB + …
P1 V1 P2 V2
T1 = T2
vA
MMB
vB =
MMA


total
Solubility Rules for Salts
Always soluble:
 alkali ions, NH4+, NO3−, ClO3−, ClO4−, C2H3O2−, HCO3−
Generally soluble:
 Cl−, Br−, I−
Soluble except with Ag+, Pb2+, Hg22+
−
 F
Soluble except with Pb2+, Ca2+, Ba2+, Sr2+, Mg2+
 SO42−
Soluble except with Pb2+, Ca2+, Ba2+, Sr2+
Generally insoluble:
 O2−, OH−
Insoluble except with Ca2+, Ba2+, Sr2+,
alkali ions, NH4+
 CO32−, PO43−, S2−, SO32−, CrO42−, C2O42−
Insoluble except with alkali ions and NH4+
PV = nRT
Strong Acids
HCl, HBr, HI, HNO3, H2SO4, HClO3,
HClO4, HIO4
Strong Bases
LiOH, NaOH, KOH, RbOH, CsOH,
Ca(OH)2, Sr(OH)2, Ba(OH)2
Gases that Form
 H2S (g)
 H2CO3 (aq)  CO2 (g) + H2O (ℓ)
 H2SO3 (aq)  SO2 (g) + H2O (ℓ)
 NH4OH (aq)  NH3 (g) + H2O (ℓ)