Question 1

In the reaction of HCl with water:   The following species forms. ​   In the given energy diagram, which letter represents this species?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E C

Question 2

Which of the following can be the equilibrium constant for a reaction that proceeds very far in the direction of the products?

Accepted Answer

A)  2 × 10-15 
B)  2 × 10-2 
C)  2× 102 
D)  2 × 1015 
A)  2 × 10-15 
B)  2 × 10-2 
C)  2× 102 
D)  2 × 1015 D

Question 3

For the reaction   equilibrium is established at 25°C when [NOCl] = 2.1 M, [NO] = 1.2 M, and [Cl2] = 0.30 M. What is the equilibrium constant for this reaction?

Accepted Answer

A)  0.098 
B)  0.18 
C)  5.4 
D)  1.0 × 101 
A)  0.098 
B)  0.18 
C)  5.4 
D)  1.0 × 101 A

Question 4

For the reaction 2C → A + B, 0.02 mol of A is formed during the first 15 seconds of the reaction. Assuming that the rate of reaction remains constant for 2 min, which of the following statements is true?

Accepted Answer

A)  After 2 min, 0.16 mol of B was produced. 
B)  After 2 min, 0.32 mol of C was consumed. 
C)  After 2 min, 0.16 mol of B was produced and .32 mol of C was consumed. 
D)  None of these. 
A)  After 2 min, 0.16 mol of B was produced. 
B)  After 2 min, 0.32 mol of C was consumed. 
C)  After 2 min, 0.16 mol of B was produced and .32 mol of C was consumed. 
D)  None of these.

Question 5

Which of the following will change the numerical value of the equilibrium constant of a particular reaction?

Accepted Answer

A)  increasing the concentration of the products 
B)  increasing the temperature 
C)  increasing the concentration of the reactants 
D)  increasing the concentration of the catalysts 
A)  increasing the concentration of the products 
B)  increasing the temperature 
C)  increasing the concentration of the reactants 
D)  increasing the concentration of the catalysts

Question 6

How does the rate of reaction change when the reactant is used up over the course of a reaction?

Accepted Answer

A)  The rate of reaction always decreases. 
B)  The rate of reaction usually decreases. 
C)  The rate of reaction always increases. 
D)  The rate of reaction usually increases. 
A)  The rate of reaction always decreases. 
B)  The rate of reaction usually decreases. 
C)  The rate of reaction always increases. 
D)  The rate of reaction usually increases.

Question 7

What is the effect of adding CH3COOC2H5(g)to a container in which the following reaction has reached equilibrium?

Accepted Answer

A)  The reaction will shift from the left to the right. 
B)  The reaction will shift from the right to the left. 
C)  There will be no effect. 
D)  Whether the reaction will shift to the left or the right depends on the initial temperature. 
A)  The reaction will shift from the left to the right. 
B)  The reaction will shift from the right to the left. 
C)  There will be no effect. 
D)  Whether the reaction will shift to the left or the right depends on the initial temperature.

Question 8

Which of the following does not result from increasing the temperature of a reaction?

Accepted Answer

A)  The fraction of effective collisions increases. 
B)  The concentrations of the reactants increase. 
C)  There are more collisions. 
D)  None, all of these are a result of increasing the temperature. 
A)  The fraction of effective collisions increases. 
B)  The concentrations of the reactants increase. 
C)  There are more collisions. 
D)  None, all of these are a result of increasing the temperature.

Question 9

In an energy diagram for an endothermic chemical reaction, which of the following is true?

Accepted Answer

A)  The energy of the products is lower than that of the reactants. 
B)  The energy of the transition state is higher than that of the reactants. 
C)  The energy of the products is lower that that of the reactants and the energy of the transition state is higher than that of the reactants. 
D)  None of these. 
A)  The energy of the products is lower than that of the reactants. 
B)  The energy of the transition state is higher than that of the reactants. 
C)  The energy of the products is lower that that of the reactants and the energy of the transition state is higher than that of the reactants. 
D)  None of these.

Question 10

In an equilibrium constant expression, what does the notation [A]3 represent?

Accepted Answer

A)  [A] + [A] + [A] 
B)  1/([A] + [A] + [A]) 
C)  [A] × [A] × [A] 
D)  1/([A] × [A] × [A]) 
A)  [A] + [A] + [A] 
B)  1/([A] + [A] + [A]) 
C)  [A] × [A] × [A] 
D)  1/([A] × [A] × [A])

Question 11

For the reaction   equilibrium is established at 472°C when [H2] = 0.0400 M, [N2] = 0.0200 M, and [NH3] = 1.074 × 10-8M. What is the equilibrium constant for the reverse reaction?

Accepted Answer

A)  3.72 × 103 
B)  1.109 × 1011 
C)  1.39 × 109 
D)  6.94 × 1010 
A)  3.72 × 103 
B)  1.109 × 1011 
C)  1.39 × 109 
D)  6.94 × 1010

Question 12

Consider the following energy diagram for a reaction.   Which letter represents the net energy change of the reaction?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E

Question 13

Which of the following is true of the rates of most chemical reactions?

Accepted Answer

A)  The initial rate cannot be measured. 
B)  The initial rate is faster than the rate later in time. 
C)  The initial rate is the same as the rate later in time. 
D)  The initial rate is slower than the rate later in time. 
A)  The initial rate cannot be measured. 
B)  The initial rate is faster than the rate later in time. 
C)  The initial rate is the same as the rate later in time. 
D)  The initial rate is slower than the rate later in time.

Question 14

Consider a sample of water in a closed, rigid container. Which of the following will indicate that the given physical process has reached equilibrium?

Accepted Answer

A)  The mass of the container remains constant. 
B)  The vapor pressure in the container remains constant. 
C)  The volume of water in the container increases from its original level. 
D)  All of these indicate that the reaction has reached equilibrium. 
A)  The mass of the container remains constant. 
B)  The vapor pressure in the container remains constant. 
C)  The volume of water in the container increases from its original level. 
D)  All of these indicate that the reaction has reached equilibrium.

Question 15

A particular reaction has an equilibrium constant of 1 x 10-15. Which of the following best describes the relationship between the equilibrium constant and the reaction rate?

Accepted Answer

A)  Because the equilibrium constant is small, the reaction proceeds slowly. 
B)  There is no relationship between the size of the equilibrium constant and the rate of the reaction. 
C)  Because the equilibrium constant is small, the reaction proceeds slowly, and there is no relationship between the size of the equilibrium constant and the rate of the reaction. 
D)  None of these. 
A)  Because the equilibrium constant is small, the reaction proceeds slowly. 
B)  There is no relationship between the size of the equilibrium constant and the rate of the reaction. 
C)  Because the equilibrium constant is small, the reaction proceeds slowly, and there is no relationship between the size of the equilibrium constant and the rate of the reaction. 
D)  None of these.

Question 16

If a chemist wishes to react a solid with a liquid, which of the following will be the least effective in speeding up the reaction?

Accepted Answer

A)  adding more liquid reactant 
B)  grinding the solid to a form a powder 
C)  dissolving the solid and the liquid in a solvent 
D)  using the frozen form of the liquid 
A)  adding more liquid reactant 
B)  grinding the solid to a form a powder 
C)  dissolving the solid and the liquid in a solvent 
D)  using the frozen form of the liquid

Question 17

If a chemist wishes to react a solid with a liquid, which of the following will be the most effective in speeding up the reaction?

Accepted Answer

A)  adding more liquid reactant 
B)  grinding the solid to a form a powder 
C)  placing a large crystal of the solid in a beaker containing the liquid reactant 
D)  all of these 
A)  adding more liquid reactant 
B)  grinding the solid to a form a powder 
C)  placing a large crystal of the solid in a beaker containing the liquid reactant 
D)  all of these

Question 18

Which of the following will change the numerical value of the equilibrium constant of a particular reaction?

Accepted Answer

A)  increasing the concentration of the reactants 
B)  increasing the concentration of the products 
C)  increasing the concentration of the reactants and the products 
D)  none of these 
A)  increasing the concentration of the reactants 
B)  increasing the concentration of the products 
C)  increasing the concentration of the reactants and the products 
D)  none of these

Question 19

Why will increasing the temperature of a reaction speed up the reaction?

Accepted Answer

A)  because the activation energy for the reaction is lowered 
B)  because the heat of reaction is increased 
C)  because there are more effective collisions between molecules 
D)  none of these 
A)  because the activation energy for the reaction is lowered 
B)  because the heat of reaction is increased 
C)  because there are more effective collisions between molecules 
D)  none of these

Question 20

Consider the following energy diagram for a reaction.   Which of the following is a correct interpretation of the graph?

Accepted Answer

A)  The energy of the products is less than that of the reactants, so the reaction is endothermic. 
B)  The energy of the products is greater than that of the reactants, so the reaction is endothermic. 
C)  The energy of the products is less than that of the reactants, so the reaction is exothermic. 
D)  The energy of the products is greater than that of the reactants, so the reaction is exothermic. 
A)  The energy of the products is less than that of the reactants, so the reaction is endothermic. 
B)  The energy of the products is greater than that of the reactants, so the reaction is endothermic. 
C)  The energy of the products is less than that of the reactants, so the reaction is exothermic. 
D)  The energy of the products is greater than that of the reactants, so the reaction is exothermic.

Exam 7: Reaction Rates and Chemical Equilibrium

In the reaction of HCl with water: The following species forms. ​ In the given energy diagram, which letter represents this species?

Which of the following can be the equilibrium constant for a reaction that proceeds very far in the direction of the products?

For the reaction equilibrium is established at 25°C when [NOCl] = 2.1 M, [NO] = 1.2 M, and [Cl2] = 0.30 M. What is the equilibrium constant for this reaction?

For the reaction 2C → A + B, 0.02 mol of A is formed during the first 15 seconds of the reaction. Assuming that the rate of reaction remains constant for 2 min, which of the following statements is true?

Which of the following will change the numerical value of the equilibrium constant of a particular reaction?

How does the rate of reaction change when the reactant is used up over the course of a reaction?

What is the effect of adding CH3COOC2H5(g)to a container in which the following reaction has reached equilibrium?

Which of the following does not result from increasing the temperature of a reaction?

In an energy diagram for an endothermic chemical reaction, which of the following is true?

In an equilibrium constant expression, what does the notation [A]3 represent?

For the reaction equilibrium is established at 472°C when [H2] = 0.0400 M, [N2] = 0.0200 M, and [NH3] = 1.074 × 10-8M. What is the equilibrium constant for the reverse reaction?

Consider the following energy diagram for a reaction. Which letter represents the net energy change of the reaction?

Which of the following is true of the rates of most chemical reactions?

Consider a sample of water in a closed, rigid container. Which of the following will indicate that the given physical process has reached equilibrium?

A particular reaction has an equilibrium constant of 1 x 10-15. Which of the following best describes the relationship between the equilibrium constant and the reaction rate?

If a chemist wishes to react a solid with a liquid, which of the following will be the least effective in speeding up the reaction?

If a chemist wishes to react a solid with a liquid, which of the following will be the most effective in speeding up the reaction?

Which of the following will change the numerical value of the equilibrium constant of a particular reaction?

Why will increasing the temperature of a reaction speed up the reaction?

Consider the following energy diagram for a reaction. Which of the following is a correct interpretation of the graph?

Matter, Energy, and Measurement

Atoms

Chemical Bonds

Chemical Reactions

Gases, Liquids, and Solids

Solutions and Colloids

Acids and Bases

Nuclear Chemistry

Organic Chemistry

Alkanes

Alkenes, Alkynes, and Aromatic Compounds

Alcohols, Ethers, and Thiols

Chirality: the Handedness of Molecules

Amines

Aldehydes and Ketones

Carboxylic Acids

Carboxylic Anhydrides, Esters, and Amides

Carbohydrates

Lipids

Proteins

Enzymes

Chemical Communications: Neurotransmitters and Hormones

Nucleotides, Nucleic Acids, and Heredity

Gene Expression and Protein Synthesis

Bioenergetics: How the Body Converts Food to Energy

Specific Catabolic Pathways: Carbohydrate, Lipid, and Protein Metabolism

Biosynthetic Pathways

Nutrition

Immunochemistry

Body Fluids

Filters

In the reaction of HCl with water: The following species forms. In the given energy diagram, which letter represents this species?

For the reaction equilibrium is established at 25°C when [NOCl] = 2.1 M, [NO] = 1.2 M, and [Cl₂] = 0.30 M. What is the equilibrium constant for this reaction?

What is the effect of adding CH₃COOC₂H₅(g)to a container in which the following reaction has reached equilibrium?

In an equilibrium constant expression, what does the notation [A]³ represent?

For the reaction equilibrium is established at 472°C when [H₂] = 0.0400 M, [N₂] = 0.0200 M, and [NH₃] = 1.074 × 10^-8M. What is the equilibrium constant for the reverse reaction?

A particular reaction has an equilibrium constant of 1 x 10^-15. Which of the following best describes the relationship between the equilibrium constant and the reaction rate?