TEST NAME: Final Review Three Reactions Stoichiometry
TEST ID: 1098492
GRADE: 11 ­ Eleventh Grade ­ 12 ­ Twelfth Grade
SUBJECT: Life and Physical Sciences
TEST CATEGORY: School Assessment
Final Review Three Reactions Stoichiometry
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Student: Class:
Date:
1. A student placed a small amount of baking soda in a watch glass. When 15 drops of vinegar
were added, the solution began fizzing. The watch glass was placed on a warm hot plate to
evaporate the liquid. The solid, white crystals remaining after evaporation were different in
appearance than the baking soda. Part A: Which observation most likely indicated that a chemical change had occurred?
Part B: Why were the remaining crystals in the watch glass different than the original baking
soda crystals?
2. Missy and Ethan discussed examples of the types of changes in matter. In which example is
a chemical change taking place?
A.
A piece of metal is cut in half.
B.
An ice cube melts on a counter.
C.
A camper roasts marshmallows over a burning fire.
D.
A baker mixes together flour and sugar to make dough.
3. Emily made a chart that included physical changes and chemical changes. Which change
should be categorized as a chemical change?
A.
iron becomes rusty
B.
a gold bar is melted
C.
lake water evaporates
D.
a granite rock is polished
4. A science class is doing an experiment performing the procedure shown.
Experimental Procedure
1. Grind salt into a powder.
2. Heat a small beaker of water.
3. Completely dissolve the salt in the water while stirring.
4. Add silver nitrate solution to form a white solid.
During which step of this procedure does a chemical change occur?
A.
1
B.
2
C.
3
D.
4
Final Review Three Reactions Stoichiometry
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5. Magnesium strips are long, thin strips that are gray and shiny. Which action will lead to a
chemical change of magnesium strips?
A.
putting them in the freezer
B.
burning them with a candle
C.
cutting them into small pieces
D.
mixing them with pieces of copper
6. Chemical change can be identified by specific observations. Which would most likely indicate a
chemical change?
A.
Solid carbon dioxide changes directly into carbon dioxide gas.
B.
Rock is slowly worn away by the action of wind and sand.
C.
A mineral is crushed into fine dust and mixed with water.
D.
A light green powder forms on the outside of a penny.
7. When a scientist performs an experiment, there are many changes that can occur. Which
observation should she list as a chemical change?
A.
The substance was heated.
B.
The shape of the substance changed.
C.
The volume of the substance changed.
D.
The substance changed into a new substance.
8. Which is evidence of a chemical reaction?
A.
the light produced by magnesium when burned
B.
the evaporation of water from a solution
C.
the fizzing of a soft drink
D.
the heat from a light bulb
9.
Which of these compounds will form a precipitate when mixed with an
aqueous solution of sodium sulfate, Na2SO4?
A.
LiNO3
B.
KNO3
C.
Mg(NO3)2
D.
Ba(NO3)2
Final Review Three Reactions Stoichiometry
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10. When geologists are trying to identify certain rocks, they often place a few drops of diluted
hydrochloric acid on the rocks. Sometimes the rocks effervesce when acid is dropped on them.
What are the geologists most likely trying to determine?
A.
the age of the rocks
B.
the density of the rocks
C.
the amount of minerals in the rocks
D.
the chemical properties of the rocks
11. Which activity is an example of a chemical change?
A.
sugar dissolving in water
B.
water evaporating in air
C.
lighting a match
D.
freezing water
12. Oxygen reacts with iron to produce rust and with hydrogen to produce water. Which statement
describes both reactions?
A.
A different mixture is formed in each case.
B.
A different solution is formed in each case.
C.
Both a change of state and of elements is involved.
D.
New molecules are formed but the same elements exist.
13. A marshmallow is cooked over a campfire. • Identify the type of change that occurs.
• Describe the evidence that shows this type of change has occurred.
Final Review Three Reactions Stoichiometry
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14. The chart shows how materials can change chemically.
Original Material
Piece of iron
Event
Change
Left outdoors in the rain Rust forms
Stack of firewood Used in fireplace
Becomes smoke and ashes
Copper penny
Gas bubbles form
Placed in vinegar
Why are these changes classified as chemical changes?
A.
New substances are formed.
B.
Materials take different shapes.
C.
Temperature affects the objects.
D.
Some energy is absorbed.
15. In a classroom demonstration, a teacher pours sulfuric acid on some granulated sugar in a
beaker. The sugar turns yellow and then black. Smoke rises and a strong smell is released. This
demonstration is an example of what kind of change?
A.
chemical
B.
physical
C.
magnetic
D.
electric
16. Ozone is three oxygen atoms bonded together. It can sometimes be smelled in the air after a
thunderstorm.
The smell is a result of
A.
pollution.
B.
condensation.
C.
a chemical change.
D.
a physical change.
17. Which event is an example of a chemical change?
A.
fog rising off a river
B.
wood burning in a fireplace
C.
ice cream melting in the sunshine
D.
grinding peppercorn into pepper flakes
18. Which is an indication that a chemical change is taking place?
A.
Iron changes color when heated.
B.
Gas bubbles form in boiling water.
C.
Solid wax forms when melted wax falls in ice water.
D.
A gas forms when vinegar and baking soda are mixed.
Final Review Three Reactions Stoichiometry
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19. Which is an example of a chemical change?
A.
sand separated from water by filtering
B.
water evaporating from a puddle
C.
a rock being eroded by wind
D.
a nail rusting in water
20. A student mixed some yellow sulfur powder with some iron filings. She was able to take the
iron out of the sulfur by using a magnet. She then remixed the iron and sulfur in a test tube and
heated it. After it cooled, she removed the substance from the test tube but could not separate
the iron from the sulfur using the magnet. Which type of change occurred in the material when
it was heated?
A.
a physical change because the iron reacted with the sulfur
B.
a chemical change because a new substance was formed
C.
a physical change because a compound was formed
D.
a chemical change because a magnet had to be used
21. Examine the activity series of metals in this table. Name
Symbol
Lithium
Li
Barium
Ba
Strontium
Sr
Calcium
Ca
Magnesium
Mg
Zinc
Zn
Iron
Fe
Decreasing
reactivity
↓
↓
↓
Based on the activity series, which metal could X represent in the reaction below?
A.
Ba
B.
Fe
C.
Mg
D.
Zn
22. Iron(III) chloride reacts with potassium hydroxide to yield potassium chloride and iron(III)
hydroxide. The overall reaction is shown below.
What is the ionic equation for this reaction?
A.
B.
C.
→
D.
→
Final Review Three Reactions Stoichiometry
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23.
Solid chromium(II) reacts with oxygen gas to form solid CrO. What is this
type of reaction?
A.
decomposition
B.
synthesis
C.
single replacement
D.
double replacement
24. The formula
shows that
A.
X and Y bonded into a more complex molecule.
B.
ZY has decomposed into two smaller compounds.
C.
X is a more reactive compound than Y.
D.
Y has changed into a new compound.
25. Three common acid­base neutralization reactions are shown below.
Which characteristic is shared by all three reactions?
A.
All of the acid reactants are classified as weak acids.
B.
All of the reactions are double­replacement reactions.
C.
All of the base products are classified as strong bases.
All of the reactions produce H3O+­ as the conjugate acid.
D.
26. Which element should be filled in to make this equation correct?
A.
Ca
B.
S
C.
C
D.
N
27. What is the net ionic equation for the reaction between silver nitrate (AgNO3) and sodium
hydroxide (NaOH)?
A.
B.
C.
→
D.
→
Final Review Three Reactions Stoichiometry
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28. Which equation for the complete combustion of propane (C3H8) is correctly balanced?
A.
B.
C.
D.
29. What type of reaction is shown below?
A.
synthesis
B.
combustion
C.
decomposition
D.
single replacement
30. What is the balanced equation for the decomposition of iron(III) hydrogen carbonate?
A.
B.
C.
D.
31. Which set of coefficients correctly balance the equation below?
A.
B.
1, 3, 1, 1
C.
2, 3, 1, 1
D.
2, 3, 1, 3
Final Review Three Reactions Stoichiometry
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32. Some solubility rules are listed below.
Soluble
• All nitrates, acetates, ammonium, and Group 1 (IA) salts
• All chlorides, bromides, and iodides
except silver, lead, and mercury(I)
• All fluorides except Group 2 (IIA),
lead(II), and iron(III) • All sulfates except calcium,
strontium, barium, mercury,
lead(II), and silver
Insoluble (0.10 M or greater)
• All carbonates and phosphates
except Group 1 (IA) and
ammonium • All hydroxides except Group 1
(IA), strontium, barium,
and ammonium
• All sulfides except Group 1 (IA),
Group 2 (IIA), and ammonium • All oxides except Group 1 (IA)
Based on these rules, what would the precipitate be in the reaction below?
A.
B.
C.
D.
Ag2SO4
ZnCl2
Ag2SO4 and ZnCl2
No precipitate will form.
33. The chemical equation represents a reaction between ammonia and oxygen to form nitrogen
monoxide and water.
What is the limiting reagent when a 2.00 g sample of ammonia is mixed with 4.00 g of oxygen?
A.
oxygen
B.
ammonia
C.
water
D.
nitrogen monoxide
34. The equation for the synthesis of water is given below.
How many grams of oxygen gas are needed to produce 36.0 grams of water?
A.
9.00 grams
B.
16.0 grams
C.
32.0 grams
D.
40.0 grams
Final Review Three Reactions Stoichiometry
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35. How many molecules of water are produced by the combustion of 3.00 g of methane?
A.
B.
C.
D.
36. The diagram shows a chemical equation for the production of sodium chloride, NaCl.
When 2.3 g of Na(s) reacts with excess
A.
2.3 g
B.
4.6 g
C.
6.9 g
D.
5.9 g
, how many grams of NaCl will be produced?
37. The reaction between FeS and
How many liters of
A.
1.2
B.
2.5
C.
3.8
D.
7.6
shown below produces the gas
.
gas, at STP, will be produced from 3.1 grams of oxygen?
38. Magnesium chloride has an atomic mass of 94 amu. What is the mass of one mole of
magnesium chloride?
A.
3 g
B.
47 g
C.
94 g
D.
188 g
39. The chemical equation shows the production of magnesium chloride.
How many grams of H2 will be produced from 12 grams of Mg?
A.
1.0
B.
2.0
C.
3.0
D.
4.0
Final Review Three Reactions Stoichiometry
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40. The chemical reaction shows the production of sulfur trioxide.
Which of the following reactant quantities would make oxygen gas the limiting reagent?
A.
2 mol
: 1 mol
B.
2 mol
: 2 mol
C.
3 mol
: 1 mol
D.
2 mol
: 3 mol
41. Nitrogen and hydrogen react to produce ammonia.
How many grams of hydrogen are needed to produce 15.0 mol of ammonia if the reaction goes
to completion?
A.
15.0 g
B.
22.5 g
C.
45.0 g
D.
90.0 g
42. During an investigation, a student burns magnesium to form magnesium oxide. The starting
mass of magnesium is measured as 21.3 g. If the student recovers 30.2 g of magnesium oxide, what is the percent yield? (atomic mass of
magnesium = 24.3 amu)
A.
63.4%
B.
70.5%
C.
74.9%
D.
86.0%
43. Which statement characterizes the activation energy of a chemical reaction?
A.
The activation energy allows the reactants to form the activated complex.
B.
The activation energy decreases the kinetic energy of the reactants.
C.
The activation energy results from collisions between the reactants.
D.
The activation energy forms when the products are created.
Final Review Three Reactions Stoichiometry
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44. Activation energy is required to begin a reaction. The graph shows a reaction with two different
activation energies.
In each reaction, the temperature and concentration of the reactants was the same. Which best
explains the reduction in the activation energy for Reaction 2?
A.
A catalyst was present during Reaction 2.
B.
The investigation was conducted closer to the heat source.
C.
Higher quality reactants were used during Reaction 1.
D.
A different type of glassware was used during Reaction 1.
45. The rate of a reaction depends on many factors such as the concentration of the reactants.
Which of the following explains why an increase in the concentration of reactants affects the
rate of reaction?
A.
The reactants move faster.
B.
The activation energy is lowered.
C.
There are fewer molecules present.
D.
The collisions increase between the reactants.
46. The rate at which a reaction occurs depends on the collisions between the molecules in the
reactants. Which best describes the result of a temperature increase on the collisions of the
molecules?
A.
The molecules are compressed, which decreases the number of collisions.
B.
The number of molecules increases, which increases the frequency of collisions.
C.
The molecules move faster, which increases the energy released by the collisions.
D.
The surface area of the molecules increases, which makes the collisions more effective.
Final Review Three Reactions Stoichiometry
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47. A chemist tested the reaction of potassium chlorate
and iron (II) sulfate
. The
independent variable is temperature; all other variables are constant. The results were
recorded.
Temperature
(degrees Kelvin) Reaction Rate
(grams per second) 285 1 290 2 295 3 These results support which conclusion?
A.
An increase in temperature increased the amount of reactant present.
B.
An increase in temperature increased the catalytic behavior of reactants.
C.
An increase in temperature increased the rate of collision of reactant molecules.
D.
An increase in temperature increased the mass of each molecule of reaction product.
48. The graph shows two reactions where Reactants W and X yield Products Y and Z.
Which statement best describes how Reaction 1 and Reaction 2 are different from each other?
A.
Reaction 1 requires a catalyst to proceed.
B.
Reaction 2 releases less energy than Reaction 1.
C.
Reaction 2 happens in the presence of a catalyst.
D.
Reaction 2 requires a greater activation energy than Reaction 1.
49. In a regular combustion engine, fuel and air are compressed in a cylinder, and the mixture is
then ignited by an electric spark plug. In a diesel engine, only air is compressed. When it is at
its maximum compression, fuel is added to the cylinder, and it then ignites. The air in a diesel
engine is compressed to a higher pressure than in a regular engine.
Describe how increasing the pressure of the air affects its temperature.
Describe how this pressure change permits the mixture of air and fuel to ignite without a
spark plug.
Final Review Three Reactions Stoichiometry
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50. Which of these conditions is most likely to increase the rate of interaction among atoms and
molecules?
A.
presence of a catalyst
B.
decrease in temperature
C.
low concentration
D.
increase in particle size
51. A researcher studies the rate of chemical reactions at different temperatures.
Based on the data, what occurs during this reaction?
A.
The reaction rate increases as the temperature increases.
B.
The amount of product increases as the reaction rate increases.
C.
Mass increases.
D.
Mass decreases.
Final Review Three Reactions Stoichiometry
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52. Two gases react chemically when they are mixed. Which graph best illustrates the relationship
between their reaction rate and the gas pressure in a chamber holding them?
A.
B.
C.
D.
53. Zinc (Zn) granules react slowly with dilute hydrochloric acid (HCl), but much faster if the acid is
concentrated.
What causes the reaction to proceed faster with concentrated acid?
A.
The pressure of hydrogen gas molecules increases as concentration increases.
B.
The concentrated hydrochloric acid molecules move faster than in dilute acid.
C.
The concentrated hydrochloric acid causes more hydrogen gas to be produced.
D.
There are more collisions between the zinc and concentrated hydrochloric acid.
54. A group of chemists is researching the conversion of carbon dioxide
into hydrocarbon fuels
at room temperature. This reaction is performed using sunlight and tiny catalyst particles made
of platinum (Pt) and palladium (Pd). What could the chemists do to increase the rate of
reaction?
A.
increase the size of the catalyst particles
B.
decrease the temperature of the reaction
C.
increase the pressure of the carbon dioxide
D.
decrease the concentration of carbon dioxide
Final Review Three Reactions Stoichiometry
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55. Hydrogen peroxide reacts to produce water and oxygen. Manganese (IV) oxide acts as a
catalyst for this reaction. At Point 1, manganese (IV) oxide is added to a sample of hydrogen
peroxide which is already reacting. Which change in reaction rate should be expected?
A.
B.
C.
D.
56. Jane and Larry are investigating the formation of nitrogen dioxide
monoxide (NO) and oxygen
from nitrogen
The equation for the reaction is shown.
During their investigation, they increase the pressure on the reaction by reducing the volume of
the reaction container. What will be the most likely effect of increasing the pressure?
A.
The rate of consumption of NO will decrease.
B.
The rate of production of
C.
The reverse reaction will take place.
D.
The reaction will reach equilibrium.
will increase.
Final Review Three Reactions Stoichiometry
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57. Iron naturally reacts with moisture and oxygen in the atmosphere to produce rust. Identify two
ways that a 1 kg block of iron could be made to rust more quickly. Explain the effectiveness of
each method.
58. Two gases chemically react when they are mixed with each other. Equal masses of each gas
are placed in a sealed chamber. Which change to the reaction chamber will most likely
increase the reaction rate of the gases?
A.
adding an inert gas to the chamber
B.
reducing the volume of the chamber
C.
increasing the surface area of the chamber
D.
reducing the temperature inside the chamber
59. The reaction between calcium carbonate and hydrochloric acid is shown.
Which would increase the reaction rate between calcium carbonate and hydrochloric acid?
A.
increasing the concentration of calcium chloride
B.
decreasing the amount of hydrochloric acid
C.
crushing the calcium carbonate into a powder
D.
decreasing the concentration of hydrochloric acid
60. In order to manufacture ammonia
in large amounts for commercial use, the rate of
reaction between hydrogen (H) and nitrogen (N) is increased by combining them under high
pressure. Which of the following best explains why increasing pressure increases the rate of
reaction between gas reactants?
A.
Their concentrations will increase.
B.
Their activation energy will increase.
C.
Their atoms will be physically forced to combine.
D.
Their gases will be forced to condense to a liquid.
61. In a modern car engine, a mist of fuel is sprayed into a chamber where it mixes with air. This
mixture is then ignited.
The surface area of the fuel is maximized in this system. This maximization benefits the function
of the system by increasing which factor?
A.
the reactivity of fuel with air
B.
the kinetic energy of the fuel
C.
the reaction rate of fuel and air
D.
the chemical energy of the fuel
Final Review Three Reactions Stoichiometry
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62. The chemical reaction between the reagents luminol and bleach produces a brief flash of light.
Which change would most likely make the light produced in the reaction last longer?
A.
adding a catalyst
B.
decreasing the temperature
C.
increasing the luminol concentration
D.
decreasing the quantity of both reagents
63. Hydrogen peroxide
Manganese dioxide
naturally dissociates to form oxygen
and water
acts as a catalyst for this reaction. Which correctly describes how the
presence of manganese dioxide affects this reaction?
A.
It increases the reaction rate.
B.
It increases the reaction time.
C.
It increases the reactant mass.
D.
It increases the reactant concentration.
64. Pepsin is an enzyme that acts in the stomach for protein digestion. Which of these is most likely
the main role of pepsin in this metabolic reaction?
A.
to speed up the rate of reaction
B.
to reduce the loss of energy as heat
C.
to control the direction of the reaction
D.
to protect the reaction from other chemicals
65. Mark and Elizabeth are combining two substances, X and Y, in chemistry class. Substance X is a
solid and Substance Y is a liquid. They are investigating the rate of reaction between the two
substances. In a reaction between Substances X and Y, which action would most likely increase
the reaction rate?
A.
adding more of X and Y
B.
lowering the temperature of Y
C.
using smaller sized particles of X
D.
increasing the pressure on X and Y
Final Review Three Reactions Stoichiometry
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66. A science class is performing the experiment shown by adding a piece of zinc (Zn) to 5 mL of
2M hydrochloric acid (HCl). The teacher wants the students to determine if the shape of the zinc
will affect the rate of the reaction.
Which of the samples of zinc should produce the highest rate of reaction if all of the samples
have the same mass?
A.
B.
C.
D.
Final Review Three Reactions Stoichiometry
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67. Hydrogen gas molecules
and oxygen gas molecules
react to form water. Argon (Ar) gas
does not react with either oxygen or hydrogen. Platinum (Pt) acts as a catalyst in the reaction
between hydrogen and oxygen. The formation of water takes place in the container shown.
In which container will the formation of water occur at the same rate as in the container above?
A.
B.
C.
D.
Final Review Three Reactions Stoichiometry
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68. Equal masses of steel wool are placed in four beakers. Equal amounts of hydrochloric acid (HCl)
are added to three beakers in the following concentrations: 0.5 M, 1.0 M, and 3.0 M. Water is
added to the fourth beaker. Hydrochloric acid reacts with the metal in steel wool. Which
observation is most likely?
A.
The steel wool in the 0.5 M HCl reacts fastest.
B.
The steel wool in the 3.0 M HCl reacts fastest.
C.
The mixtures react in the same amount of time.
D.
The control reacts in the shortest amount of time.
69. What does the line indicated by the letter A in the diagram below refer to?
A.
an exothermic reaction
B.
an endothermic reaction
C.
activation energy of a reaction
D.
effect of temperature on a reaction
70. Two light sticks are bent and shaken to mix the reactants. Each stick has the same initial light
intensity. One stick is placed in hot water, and another in ice water. After several minutes, the
stick in the hot water glows very brightly, while the stick in the cold water has dimmed. Which
of the following best explains the difference in light intensity between sticks?
A.
Light moves substantially faster through hot materials than cold materials.
B.
The high temperature tube had an increased surface area which allowed more light to escape than the
cold temperature tube.
C.
Light moves substantially slower through hot materials than cold materials.
D.
The high temperature increased the reaction rate of the light emitting reactants, while the low temperature
reduced the reaction rate.
71. A reaction occurs between two gases when they are mixed. Which is the most likely effect on
reaction rate if the gases are mixed at the same temperature but at higher pressure?
A.
Reaction rate increases because the molecules collide more often.
B.
Reaction rate increases because the molecules collide with more force.
C.
Reaction rate decreases because the molecules have less room to move.
D.
Reaction rate stays the same because the molecules move at the same speed.
Final Review Three Reactions Stoichiometry
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72. Products purchased from grocery stores are dated and need to be used within a certain amount
of time. This is to protect consumers from the effects of food spoilage. Which process helps to
slow the spoilage of food products?
A.
Separate the products to avoid contamination.
B.
Add a catalyst to the product for preservation.
C.
Decrease the storage temperature of the product.
D.
Cook the products according to package instructions.
73. Which reaction, when at equilibrium, would be unaffected by a change in pressure?
A.
B.
C.
D.
74. The equation shows an equation at equilibrium.
Which of the following describes what happens if
is added to the system?
A.
Equilibrium is restored as the reaction shifts toward the reactants.
B.
Equilibrium is restored as the reaction shifts toward the products.
C.
Equilibrium is restored as more heat energy is released from the system.
D.
Equilibrium is restored as the concentration is increased to the products.
75. The three gases in the equation are at equilibrium.
According to Le Chatelier’s principle, what would happen if more carbon monoxide were added
to the system?
A.
would react with CO to produce
to minimize the increase in CO.
B.
would react with CO to produce
to increase the production of CO.
C.
would decompose to produce CO and
to minimize the decrease in CO.
D.
would decompose to produce CO and
to increase the production of CO.
76. The chemical equation represents a reaction at equilibrium.
Which of these shows the equilibrium constant expression for this chemical equation?
A.
B.
C.
D.
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77. The following chemical reaction is at equilibrium:
Which statement is true?
A.
B.
The concentrations of SO2 and SO3 are identical.
The concentrations of SO2 and O2 are not changing.
C.
The concentration of SO3 is greater than the concentration of O2.
D.
The concentration of SO3 is changing at the same rate as the concentration of SO2.
78. What happens when a chemical reaction reaches equilibrium?
A.
The amounts of reactants and products remain constant because the reaction stops.
B.
The rate of the forward reaction is the same as the rate of the reverse reaction.
C.
The reaction stops because the concentration of reactants is too low to sustain it.
D.
The reaction reverses so some of the products are converted back into reactants.
79. The chemical equation shows the synthesis of ammonia. Which of the following will occur if there is an increase in pressure?
A.
Equilibrium will shift to the left and more nitrogen will be produced.
B.
Equilibrium will shift to the left and more hydrogen will be produced.
C.
Equilibrium will shift to the right and less heat will be produced.
D.
Equilibrium will shift to the right and more ammonia will be produced.
80. Which reaction favors the formation of product(s) as a result of increased pressure on the system
according to Le Chatelier’s principle?
A.
B.
C.
D.
81. The chemical equation represents a reversible reaction.
At equilibrium, 1 liter of a mixture of gases at 450°C contains 1.02 mol of hydrogen mol of nitrogen and 0.572 mol of ammonia 1.94
What is the equilibrium constant for the
reaction under these conditions?
A.
0.159
B.
0.290
C.
3.45
D.
6.29
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82. Which of the following must be true if a chemical reaction is at equilibrium?
A.
The chemical reaction is exothermic.
B.
The chemical reaction is reversible.
C.
The products have more energy than the reactants.
D.
All of the reactants are soluble in water.
83. Why is chemical equilibrium considered to be a dynamic state?
A.
The concentrations of reactants and products are constantly changing.
B.
The direction of the reaction continually reverses at a constant rate.
C.
The reaction proceeds in the forward and reverse directions at the same rate.
D.
The ratio of reactants and products varies depending on the reaction conditions.
84. How does the change in components of a chemical reaction at equilibrium differ from the
change in components when the reaction is not at equilibrium?
A.
At equilibrium, there is no change in components while there is always a change when the reaction is not
at equilibrium.
B.
At equilibrium, the rate of product formation is less than it is in a nonequilibrium condition.
C.
At equilibrium, the rate of reactant consumption is significantly less than it is in a nonequilibrium condition.
D.
At equilibrium, the component composition changes alternately between reactants and products while it
changes in only one direction in system that is not at equilibrium.
85. Which stress will increase the production of NO(g) in this equilibrium reaction?
A.
Constantly remove water.
B.
Increase the pressure of the reaction.
C.
Remove ammonia from the reaction mixture.
D.
Decrease the amount of oxygen in the reaction vessel.
86. A student hypothesizes that an increase in pressure will increase the amount of ammonia
produced in the reversible reaction shown. Which best explains how an increase in pressure increases the amount of ammonia present?
A.
An increase in pressure would cause the forward reaction to be endothermic.
B.
An increase in pressure tends to increase the temperature of the gases.
C.
An increase in pressure decreases the rate of reaction between gases.
D.
An increase in pressure favors the product with fewer particles.
87. How will increasing the pressure on the system affect this equilibrium reaction?
A.
shift equilibrium toward the left
B.
shift equilibrium toward the right
C.
no effect because pressure only affects equilibrium in gas state reactions
D.
no effect because silver chloride has a very low vapor pressure
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88. How will increasing the pressure in the reaction vessel affect the equilibrium of this reaction?
A.
shift equilibrium to the right because the molecules are smaller on the right
B.
shift equilibrium to the left because there are fewer gas molecules on the left
C.
shift equilibrium to the right because water is not affected by a pressure change
D.
shift equilibrium to the left because oxygen is never part of the equilibrium constant
89. How will increasing the pressure on the system affect this equilibrium reaction?
A.
increase the production of water
B.
increase the production of water
C.
no effect because there are no gas state products
D.
no effect because the system is at equilibrium
90.
The equation represents a chemical reaction at equilibrium.
HCl (aq) + Mg (s) MgCl2 (aq) + H2 (g) + heat
What happens to the system when the temperature is decreased?
A.
The reaction shifts toward the right, and the amount of hydrogen gas
increases.
B.
The reaction shifts toward the right, and the amount of hydrogen gas
decreases.
C.
The reaction shifts toward the left, and the amount of hydrogen gas
increases.
D.
The reaction shifts toward the left, and the amount of hydrogen gas
decreases.
91. How does increasing the temperature of an endothermic gas state reaction without changing
the pressure affect the equilibrium?
A.
shift equilibrium to the right
B.
shift equilibrium to the left
C.
no effect on equilibrium because the reaction is endothermic
D.
no effect on equilibrium because the reaction is in the gas state
92. How does increasing the temperature affect the equilibrium of a reversible exothermic
reaction?
A.
The concentration of reactants will increase.
B.
The concentration of products will increase.
C.
The rates of the reverse reaction will decrease.
D.
The temperature change does not affect the reaction.
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93. Ethene and steam can react to form ethanol as shown here. How will increasing temperature at
constant pressure affect this reaction?
A.
increase the amount of ethanol
B.
decrease the amount of ethanol
C.
cause the forward reaction to stop completely
D.
cause the reverse reaction to stop completely
94.
This equation represents a chemical reaction at equilibrium:
2SO2 (g) + O2 (g) 2SO3 (g)
What will happen when the concentration of SO3 is increased?
A.
The reaction shifts to the right, and concentrations of SO2 (g) and O2
(g) decrease.
B.
The reaction shifts to the right, and concentrations of SO2 (g) and O2
(g) increase.
C.
The reaction shifts to the left, and concentrations of SO2 (g) and O2
(g) decrease.
D.
The reaction shifts to the left, and concentrations of SO2 (g) and O2
(g) increase.
95. Which stress will cause the equilibrium of this reaction to shift toward the left?
A.
decrease the amount of
B.
increase the amount of
C.
decrease the amount of
D.
increase the amount of
96. The diagram represents a reversible equation at equilibrium.
Which of these actions will shift the equilibrium to the right?
A.
remove Q
B.
add X
C.
remove X
D.
add Y
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97. How will increasing the pressure in the reaction vessel affect the equilibrium of this reaction?
A.
no effect because the reaction is at equilibrium
B.
no effect because the reaction occurs in the gas state
C.
shift equilibrium to the right, decreasing the moles of gas
D.
shift equilibrium to the left, increasing the moles of gas
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