AnswersMO-Physical Science A-CRShifts in Equilibrium

Shifts in Equilibrium — Unit test Answers

23 verified answers1 views
1
Free Preview

The dissociation of a weak electrolyte is suppressed when

A
a strong electrolyte with a common ion is added to the weak electrolyte solution.
B
a strong salt is dissolved with the weak electrolyte solution.
C
a strong electrolyte with a different ion than the weak electrolyte is added.
D
the strong electrolyte solidifies in the presence of the weak electrolyte.
2
Free Preview

Consider the reaction pathway graph below. Which method would provide evidence to support the inference that this is an exothermic reaction?

Question illustration
A
add A and C
B
add E and D
C
subtract A from C
D
subtract E from D
3

Consider the chemical equilibrium of a soap that is present in its aqueous solution. C17H35COONa(aq) C17H35COO–(aq) + Na+(aq)sodium stearate (soap) stearate ion What will happen if a large quantity of NaCl is added to the aqueous solution?

Question illustration
A
The equilibrium will shift to the right, favoring the dissociation of soap in aqueous solution.
B
The equilibrium will shift to the left to such an extent that it leads to the precipitation of solid soap.
C
The equilibrium will not be affected by the addition of NaCl to the solution.
D
The equilibrium will be permanently destroyed by the addition of NaCl.
4

What happens as the activation energy increases?

A
The pressure of the system decreases.
B
The kinetic energy of colliding molecules changes.
C
The reactant surface area decreases.
D
The reaction begins to slow down.
5

Consider the reaction pathway below.Which is true about the potential energy of the reactants in this reaction pathway?

Question illustration
A
It is greater than the potential energy of the products.
B
It is less than the potential energy of the products.
C
It is equal to the potential energy of the products.
D
It is half of the potential energy of the products.
6

Consider the reaction.When does the given chemical system reach dynamic equilibrium?

Question illustration
A
when the forward and reverse reactions stop
B
when the rate of the forward reaction is higher than the rate of the reverse reaction
C
when the concentration of the reactants is higher than the concentration of the products
D
when the rates of the forward and reverse reactions are equal
7

Which will not appear in the equilibrium constant expression for the reaction below?

Question illustration
A
[H2O]
B
[C]
C
[H2]
D
[CO]
8

Which energy graph represents the nonspontaneous transition of graphite into diamond?

A
A graph with Reaction progression on the horizontal axis and energy on the vertical axis. A line starts low on the vertical axis, runs briefly parallel to the horizontal axis, slopes up sharply, curves down a short distance, and levels out.
Option A
B
A graph with Reaction progression on the horizontal axis and energy on the vertical axis. A line starts midway up the vertical axis, runs briefly parallel to the horizontal axis, slopes up sharply, curves down sharply, and levels out below the initial starting point.
Option B
C
A graph with Reaction progression on the horizontal axis and energy on the vertical axis. A line starts midway up the vertical axis, runs briefly parallel to the horizontal axis, slopes up a small amount, then curves down to level out below the initial starting point.
Option C
D
A graph with Reaction progression on the horizontal axis and energy on the vertical axis. A line starts midway up the vertical axis, runs briefly parallel to the horizontal axis, slopes up a moderate amount, then curves down sharply to level out below the initial starting point.
Option D
9

A reaction occurs when solid X is placed into solution Y. As a result, the temperature of the new solution increases by 3°C. The temperature rises another 2°C when more of solid X is added to the solution. What does this indicate about the effect of adding more solid?

A
It increased the number of molecular collisions.
B
It decreased the number of molecular collisions.
C
It decreased the space between the molecules and lowered the reaction rate.
D
It increased the space between the molecules and increased the reaction rate.
10

According to Le Chatelier’s principle, what happens when the concentration of reactants is doubled in a chemical reaction that was in equilibrium?

A
The equilibrium shifts to the right to favor the formation of products.
B
The equilibrium shifts to the left to favor the formation of reactants.
C
The equilibrium is unaffected by the increase in concentration.
D
The equilibrium is lost because the concentrations have been disturbed.
11

Consider the following equation in chemical equilibrium. C2H4(g) + H2(g) C2H6(g) + 137 kJ What happens to the amount of ethane (C2H6) when the temperature of the system is increased?

Question illustration
A
The amount of ethane decreases.
B
The amount of ethane increases initially and then decreases.
C
The amount of ethane increases.
D
The amount of ethane decreases initially and then increases.
12

Consider the following reversible reaction.What is the equilibrium constant expression for the given system?

Question illustration
A
K e q equals StartFraction StartBracket upper C upper O EndBracket StartBracket upper H 2 EndBracket superscript 2 over StartBracket upper C upper H subscript 3 upper O upper H EndBracket EndFraction.
Option A
B
K e q equals StartFraction StartBracket upper C upper H subscript 3 upper H upper O EndBracket over StartBracket upper C upper O EndBracket StartBracket upper H 2 EndBracket superscript 2 EndFraction.
Option B
C
K e q equals StartFraction StartBracket upper C upper O EndBracket StartBracket upper H 2 EndBracket over StartBracket upper C upper H subscript 3 upper O upper H EndBracket EndFraction.
Option C
D
K e q equals sart fraction StartBracket upper C upper H subscript 3 upper O StartBracket upper C upper O EndBracket StartBracket upper H 2 EndBracket EndFraction.
Option D
13

Which statement best applies collision theory to preventing a dangerous reaction from occurring?

A
Store the reactants together at a low pressure.
B
Keep all sparks or flames away from the reactants.
C
Store the reactants together at a low temperature.
D
Keep the reactants in separate containers.
14

Which statement best describes the reaction pathway graph for an exothermic reaction but not an endothermic reaction?

A
It has a hill in the middle that is the highest point.
B
It has a valley in the middle that is its lowest point.
C
The reactants are higher in energy than the products.
D
The products are higher in energy than the reactants.
15

Consider the equation below.What is the equilibrium constant expression for the given reaction?

Question illustration
A
K subscript e q equals StartFraction bracket upper C a upper O EndBracket over upper C a upper C upper O subscript 3 EndBracket EndFraction.
Option A
B
K subscript e q equals StartFraction StartBracket upper C upper O subscript 2 EndBracket StartBracket upper C a upper O EndBracket over StartBracket upper C a upper C upper O subscript 3 EndBracket EndFraction.
Option B
C
K subscript e q equals StartBracket upper C upper O subscript 2 EndBracket.
Option C
D
K subscript e q equals StartFraction 1 over StartBracket upper C upper O subscript 2 EndBracket EndFraction.
Option D
16

Consider the reaction pathway graph below.Which letter represents the activated complex?

Question illustration
A
A
B
B
C
F
D
G
17

A change in which factor will affect the rate of reaction only when gases are involved?

A
temperature
B
pressure
C
surface area
D
concentration
18

According to Le Chatelier’s principle, which statement is true?

A
The equilibrium constant is unchanged by temperature changes.
B
The equilibrium constant changes with a change in temperature.
C
The equilibrium constant increases with the concentration of reactants.
D
The equilibrium constant decreases with the concentration of products.
19

Consider the reaction below.Which is most likely the effect to the forward reaction if there is an increase in pressure of the system?

Question illustration
A
The reactant surface area increases.
B
The reaction rate decreases.
C
The reaction is not affected at all.
D
The reaction stops completely.
20

Consider the diagram below.What does C represent?

Question illustration
A
enthalpy of reaction
B
activation energy
C
activated complex
D
energy of the reactants

Did you find these answers helpful?

More from this Course

Quiz
25 verified answers

Unit Test

Quiz
10 verified answers

Shifts in Equilibrium

Quiz
9 verified answers

Shifts in Equilibrium