AP Chemistry Jeopardy

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Advanced Placement
Jeopardy 2001
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AP CHEM JEOPARDY
Thermo- dynamics
Chemical Equilibrium
Acid/Base Systems
Phases Of Matter
Reaction Kinetics
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Phases of Matter 200
DAILY DOUBLE
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Phases of Matter 200
Which accounts for the difference in length of
the lines b-c and d-e?
Temp
f
d
e
b
c
a
Time
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A) the liquid has a greater heat capacity
than the solid. B) The solid has a greater
specific heat capacity than the liquid. C) The
heat of fusion is greater than the heat of
vaporization. D) The heat of fusion is less than
the heat of vaporization.
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Youre SO smart!

• The heat of vaporization is ALWAYS greater than
  the heat of fusion because the difference in
  molecular motion from liquid to gas is much
  larger than from solid to liquid.

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Phases of Matter 400
Q - A sample of hydrogen gas is collected by
displacement of water. All of the following
describe this sample EXCEPT
A) The volume occupied by H2 is gt the volume
occupied by H2O. B) The pressure of H2 is gt the
pressure of H2O. C) The temperature of H2 is
the temperature of H2O. D) The of molecules of
H2 is gt the of molecules of H2O. E) The mass
of a molecule of H2 is lt the mass of a molecule
of H2O.
Explanation --gt
8
In the sample of wet H2 gas, both H2 and H20
occupy the same volume and have the same
temperature. At ordinary temp. and pressure, the
partial pressure of H2O is much less than the
partial pressure of H2. The molar mass of H2O is
18. The molar mass of H2 is 2. Choice (A)
claims that the gases occupy different volumes.
This is incorrect. Since both gases occupy the
same enclosed space, both have the same volume.
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Phases of Matter 600
When collecting a gas in a measuring tube by
water displacement, which of the following
properties does NOT need to be measured during
the experiment to determine the number of moles
of gas in the measuring tube?
A) atmospheric pressure B) vapor pressure of
water C) height of the water column D) volume
of H2 gas E) temp. of water in beaker
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Vapor Pressure of water is not measured but can
be found in a reference table.
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Phases of Matter 800
Which property of hydrogen sulfide is least
closely related to the polarity of its molecules?
A) Molar Mass B) solubility in water C)
critical temperature D) normal boiling pt. E)
elasticity of molecular collisions
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Phases of Matter 1000
At certain conditions, the molar volume of a real
gas may be less than the value predicted by the
ideal gas law. Which property accounts for this
deviation?
See next page for options...
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A) Each gas molecule occupies an absolute
volume. B) Forces of attraction exist between
the gas molecules. C) Resonance bonds exist
between the atoms in the molecules of the
gas. D) The average velocity of the gas
molecules is less than the value predicted by
Grahams Law. E) The kinetic energy of the gas
molecules is less than the value predicted by
the equation KE 1/2 mv2
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At low temperatures forces of attraction between
molecules accounts for lower than predicted
volume for some gases.
Another cause for deviation that does not apply
here is the absolute volume of the gas molecules.
This accounts for the higher than predicted
volume for samples of some gases at high temps.
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Phases of Matter 1200
A sample of gas is confined at constant temp. and
volume in a rigid container. If more of this
same gas is added at constant temp., what effect
is observed on pressure and average molecular
velocity?
A) Both increase
B) Pressure decreases, velocity remains same
C) Pressure remains same, velocity increases
D) Pressure increases, velocity remains same
E) Pressure remains same, velocity decreases
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Phases of Matter 1400
Which is a correct comparison of the contents of
the pistons?
I. The of molec. In each piston is the
same. II. The density of the contents of each is
the same. III. The avg. velocity of the molec.
Is each is the same.
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(A) II only (B) III only (C) I and II only (D)
II and III only (E) I, II, and III
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Chemical Equilibrium 200
For which reaction will Kc be equal to Kp?
A) H2(g) S(s) ltgt H2S(g) B) 2 H2O(g) ltgt 2
H(g) O2 (g) C) 3 H2 (g) N2 (g) ltgt 2
NH3(g) D) H2 (g) Br2 (l) ltgt 2 HBr(g)
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Therefore Kp Kc when ?n gas 0
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Chemical Equilibrium 400
The molar solubility of CaSO4 is 1.2 x 10-3 _at_ 20
C. Which expression gives the value for the
solubility product constant, Ksp, for CaSO4?
(A) 1.2 x 10-3 (C) (1.2 x 10-3)(2.4 x 10-3)2 (B)
(1.2 x 10-3)2 (D) (2.4 x 10-3)2 (C) (1.2 x
10-3)3 1.2 x 10-3
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Chemical Equilibrium 600
Consider the reaction
SO2 (g) 1/2 O2 (g) ltgt SO3(g) Kc 49 _at_
1000 K
What is the value of Kc for the reaction below? 2
SO3 (g) ltgt 2 SO2(g) O2 (g)
A) 1/49 B) 1/7 C) 1/(49)2 D) 7 E) 49
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Chemical Equilibrium 800
Which Observation confirms the fact that
equilibrium has been reached in such a system
confined in a closed, rigid container?
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A) The density remains constant. B) The odor of
ammonia can first be detected. C) The pressure
is decreasing at a constant rate. D) The partial
pressure of hydrogen remains constant. E) The
mass of the system has decreased to a constant
value.
Which Observation confirms the fact that
equilibrium has been reached in such a system
confined in a closed, rigid container?
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Equilibrium exists when there is no further
change in the macroscopic properties of the
system. Of the five observations offered, only
constant pressure of hydrogen qualifies as
evidence for existence of equilibrium. Density
and mass of the system are always constant. The
odor of ammonia can be detected even at
non-equilibrium conditions. Decreasing pressure
is evidence that equilibrium has NOT yet been
achieved.
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Chemical Equilibrium 1000
HgO(s) 4 I- (aq) H2O ltgt HgI4 2- (aq) 2
OH- (aq)
Consider the equilibrium above. Which of the
following changes will increase the HgI4 2-?
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Chemical Equilibrium 1200
The kinetic molecular theory predicts that at a
given temperature...
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A) All gases have the same KE B) All gas
molecules have the same velocity C) Only real
gas molecules collide with each other D) On
average, heavier molecules move more slowly E)
Elastic collisions result in the loss of energy.
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Chemical Equilibrium 1400
2 SO2 (g) O2 (g) ltgt 2 SO3(g) heat
Consider an equilibrium system based on the
reaction above. This equilibrium mixture is
contained in a piston.
Which occurs when the volume of the system is
increased at constant temperature?
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2 SO2 (g) O2 (g) ltgt 2 SO3(g) heat
Which occurs when the volume of the system is
increased at constant temperature?
SO2 molec.
tot. gas molec.
Kp
(A) increases decreases same (B)
increases stays same stays same (C)
increases increases stays same (D) stays
same decreases decreases (E) stays
same increases decreases
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Acid/Base Systems 200
Which is the best description of a Lewis Acid?
(A) electrophilic (B) hydrophilic (C)
nucleophilic
(D) homophilic (E) heterophilic
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Acid/Base Systems 400
Consider the 3 acids HF, HSO4-, H2PO4-
Which list includes only conjugate bases of the
acids given above?
(A) OH-, HPO43- (B) F-, SO42- and HPO42- (C)
OH-, SO42- and PO43- (D) OH, SO42- HPO42- (E)
H2F, H2SO4 and H3PO4
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Acid/Base Systems 600
When solid potassium oxide is dissolved in water,
which of the following is the strongest base in
the resulting solution?
(A) H (D) KH (B) K (E) OH - (C) O2-
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Non-metal Oxides (acid anhydrides) form an acid
when dissolved in water.
Ex. SO2 H2O --gt H2SO3
Metal Oxides (Base anhydrides) form a base when
dissolved in water.
Ex. K2O H2O --gt 2 KOH --gt 2 K 2 OH -
A Metal Oxides (Base anhydrides) and a Non-metal
Oxides (acid anhydrides) form a salt.
Ex. SO2 K2O --gt K2SO3
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Acid/Base Systems 800
Which range includes the pH that results when
0.10 mole NaOH is added to 100 mL of 1.0 M HCl
solution?
(A) between 1 and 4 (B) between 4 and 6.5 (C)
between 6.5 and 7.5 (D) between 7.5 and 10 (E)
between 10 and 14
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Acid/Base Systems 1000
When a sample of 0.0040 M HBr is diluted with an
equal amount of water, the pH of the resulting
mixture is closest to
(A) 2.3 (B) 2.7 (C) 3.0 (D) 3.3 (E) 3.7
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If it is diluted with an equal volume the
concentration is 1/2 the original 0.0020 M H
pH - log H - log 0.0020 M 2.7
- log 0.0010 3.0 - log 0.010 2.0 0.0020
falls between these but is closer to 0.0010
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Acid/Base Systems 1200
An unknown solution of H2SO4 is titrated by
adding a known concentration of NaOH until
neutralization. If, unknown to the technician,
some water had been added to the unknown H2SO4
solution by mistake after its precise volume had
been measured, which value, if any, would be
changed? If there were a change, in which
direction would the change occur?
(A) The final vol. of NaOH would be reported
larger. (B) The final vol. of NaOH would be
reported smaller. (C) The molarity of NaOH would
be reported larger. (D) The molarity of NaOH
would be reported smaller. (E) No ? would be
reported in any of the 3 values.
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Acid/Base Systems 1400
An unknown solution of H2SO4 is titrated by
adding a known concentration of NaOH until
neutralization. If, unknown to the technician,
some water had been added to the known NaOH
solution by mistake after its precise volume had
been measured, which value, if any, would be
changed? If there were a change, in which
direction would the change occur?
(A) The final vol. of NaOH would be reported
larger. (B) The final vol. of NaOH would be
reported smaller. (C) The molarity of NaOH would
be reported larger. (D) The molarity of NaOH
would be reported smaller. (E) No ? would be
reported in any of the 3 values.
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Kinetics 200
All of the following decrease the rate of a gas
phase reaction EXCEPT (A) adding inert gas (B)
removing the catalyst (C) increasing the volume
of the system (D) lowering the temperature of
the system (E) decreasing the concentration of
one of the reactants.
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Kinetics 400
A catalyst increases the rate of a chemical
reaction by (A) decreasing the PE of the
reactants (B) decreasing the PE of the
products (C) decreasing the PE of the activated
complex (D) increasing the frequency of
collisions between reactant molecules. (E)
increasing the standard free energy of formation
of the products.
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Kinetics 600
5 Br-(aq) BrO3-(g) 6 H(aq) --gt 3 Br2 (g) 3
H2O(g) What change will cause a decrease in the
rate of rxn?
I. Addition of OH - ions II. Removal of H
ions. III. Addition of H2O molecules
(A) II only (D) II and III only (B) III
only (E) I, II, and III (C) I and III only
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Kinetics 800
5 Br-(aq) BrO3-(g) 6 H(aq) --gt 3 Br2 (g) 3
H2O(g)
The rate law for the above reaction is as
follows Rate k Br-BrO3-H 2
The overall order for the reaction is (A) 2 (D)
6 (B) 3 (E) 12 (C) 4
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Kinetics 1000
DAILY DOUBLE
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Consider the reaction H2 (g) I2 (g) --gt 2
HI The rate law is Rate k H2I2 Which
mechanism is consistent with the rate law?
I. H2 ltfastgt 2 H II. H2 I2 lt slow gt 2
HI H I2 -slow-gt HI I H I -fast-gt HI
III. I2 - fast -gt 2 I H2 2 I - slow-gt
2 HI
(A) I only (D) I and II (B) II only (E) I
and III only (C) III only
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Kinetics 1200
5 Br-(aq) BrO3-(g) 6 H(aq) --gt 3 Br2 (g) 3
H2O(g)
The rate law for the above reaction is as
follows Rate k Br-BrO3-H 2
Which of the following could be the reaction
mechanism up to and including the slow step?
A. Br- H --gt Int1 B. Br- H --gt Int1
Int1 H --gt Int2 Int1 BrO3- --gt
Int2 Int2 Br- --gt Int3 Int2 H
--gt Int3
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Kinetics 1400
(A) the total pressure decreases (B) The rate
of reaction decreases (C) The entropy of the
system decreases (D) The number of molecules of
C decreases (E) The frequency of collisions
between molec. A and B decreases.
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Ox 2 I- --gt I2 2e- Red 2 H2O 2 e-
--gt H2 2 OH-
2 H2O 2 I- --gt H2 2 OH- I2
Electrolysis of KI in water. (H2O has a Ered
closer to zero than K)
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Thermodynamics 200
Which describes the change in ?G and the change
in spontaneity of the reaction as temperature
increases? N2(g) 3 H2(g) ltgt 2 NH3(g)
(A) ?G decreases to values less than 0 and the
rxn achieves equilibrium. (B) ?G decreases to
values less than 0 and the rxn becomes
spontaneous. (C) ?G decreases to values less than
0 and the rxn becomes non-spontaneous. (D) ?G
increases to values greater than 0 and the rxn
becomes spontaneous. (E) ?G increases to values
greater than 0 and the rxn becomes
non-spontaneous.
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Thermodynamics 400
Which describes the thermodynamic parameters for
the system H2O (s) ltgt H2O (l) _at_ 298K
?G ?H ?S
(A) 0 gt0 gt0 (B) 0 gt0 lt0 (C) lt0 gt0 lt0 (D) lt0
lt0 gt0 (E) lt0 gt0 gt0
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Thermodynamics 600
Which equation represents the standard formation
reaction for BaSO4 (s) at 298 K?
(A) BaS (s) 2 O2 (g)--gt BaSO4 (s) (B)
Ba2(aq) SO42-(aq)--gt BaSO4 (s) (C) Ba (s) S
(s) 2 O2 (g)--gt BaSO4 (s) (D) Ba2(aq) S6
(aq) 4 O2-(aq)--gt BaSO4 (s) (E) Ba(OH)2 (aq)
H2SO4 (aq)--gt BaSO4 (s) 2 H2O
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Thermodynamics 800
A cube of ice is added to some hot water in an
insulated container which is then sealed. There
is no heat exchange with the surroundings. Which
describes the system once it has shifted to a new
equilibrium?
I. The average KE of the liquid phase has
decreased. II. The total energy of the system
has decreased. III. The entropy of the system
has increased.
(A) I only (D) I and III only (B) III
only (E) I, II, and III (C) I and II only
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Thermodynamics 1000
?E q w
Which gives the sign convention for this
relationship that is usually used in chemistry?
Heat added Heat added work done work
done To system to surround. On system on
surround.
(A) - - - (B)
(C) - (D)
- - (E) - - -
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Thermodynamics 1200
The heat of neutralization for a strong acid in
dilute water solution is about 60 kJ/mol H.
What quantity of heat in kJ is produced when 100
mL of 3.0 M HCl is mixed with 100 mL of 1.0 M KOH?
(A) 0.10 (D) 6.0 (B) 0.30 (E) 18. (C)
0.40
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Thermodynamics 1400
The set of lettered choices is a list of symbols
used in thermodynamics and thermochemistry.
Select the one lettered choice that best fits
each statement. A choice may be used once, more
than once or not at all. (You must get them all
correct.)
(A) Kc (B) ?G (C) ?H (D) ?S (E) Ea
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(A) Kc (B) ?G (C) ?H (D) ?S (E) Ea
1. Its value is negative for any exothermic
reaction. 2. Its value is negative for any
spontaneous reaction. 3. Its value changes when
a catalyst is added to the system. 4. Its value
represents the change in randomness as the
reaction proceeds. 5. Its value is determined by
using concentrations at equilibrium in the mass
action expression.