Question 1

If heat is consumed during a reaction,the reaction is said to be ________.

Accepted Answer

A) endothermic 
B) exothermic 
C) endergonic 
D) exothermic. 
E) can't tell. 
A) endothermic 
B) exothermic 
C) endergonic 
D) exothermic. 
E) can't tell.

Question 2

-In the reaction energy diagrams shown,reaction A is ________,and it occurs ________ reaction B.

Accepted Answer

A) endergonic; faster than 
B) exergonic; faster than 
C) endergonic; slower than 
D) exergonic; slower than 
E) exergonic; at the same rate as 
A) endergonic; faster than 
B) exergonic; faster than 
C) endergonic; slower than 
D) exergonic; slower than 
E) exergonic; at the same rate as

Question 3

P4 (s)+ 10 Cl2 (g)→ 4 PCl5 (s) ΔH = -435.2 kcal
Based on the reaction shown,which statement is true?

Accepted Answer

A) When 1 mol P4 (s)reacts,435.2 kcal are released. 
B) When 1 mol PCl5 (s)is produced,435.2 kcal are released. 
C) When 30.97 g P4 (s)react,435.2 kcal are released. 
D) When 123.88 g P4 (s)react,435.2 kcal are consumed. 
E) When 208.22 g PCl5 (s)are produced,435.2 kcal are consumed. 
A) When 1 mol P4 (s)reacts,435.2 kcal are released. 
B) When 1 mol PCl5 (s)is produced,435.2 kcal are released. 
C) When 30.97 g P4 (s)react,435.2 kcal are released. 
D) When 123.88 g P4 (s)react,435.2 kcal are consumed. 
E) When 208.22 g PCl5 (s)are produced,435.2 kcal are consumed.

Question 4

A reaction which is unfavorable with respect to entropy,but favorable with respect to enthalpy

Accepted Answer

A) could occur at any temperature. 
B) could not occur regardless of temperature. 
C) could occur at low temperatures but not at higher temperatures. 
D) could occur at high temperatures but not at lower temperatures. 
E) none of the above 
A) could occur at any temperature. 
B) could not occur regardless of temperature. 
C) could occur at low temperatures but not at higher temperatures. 
D) could occur at high temperatures but not at lower temperatures. 
E) none of the above

Question 5

A reaction that is spontaneous can be described as

Accepted Answer

A) proceeding in both the forward and reverse directions. 
B) having the same rate in both the forward and reverse directions. 
C) releasing heat to the surroundings. 
D) proceeding without external influence once it has begun. 
E) increasing in disorder. 
A) proceeding in both the forward and reverse directions. 
B) having the same rate in both the forward and reverse directions. 
C) releasing heat to the surroundings. 
D) proceeding without external influence once it has begun. 
E) increasing in disorder.

Question 6

Which process is not likely to be considered reversible?

Accepted Answer

A) a round trip to Las Vegas 
B) melting wax to make candles 
C) a reaction using the symbol "↔" 
D) cutting down a tree 
E) dissolving salt in water 
A) a round trip to Las Vegas 
B) melting wax to make candles 
C) a reaction using the symbol "↔" 
D) cutting down a tree 
E) dissolving salt in water

Question 7

For the reaction given below,what quantity of heat will be produced if 90.0 g of C3H8 are consumed in the reaction?
C3H8 + 5 O2 → 3 CO2 + 4 H2O + 488 kcal

Accepted Answer

A) 996 kcal 
B) 488 kcal 
C) 332 kcal 
D) 239 kcal 
E) 976 kcal 
A) 996 kcal 
B) 488 kcal 
C) 332 kcal 
D) 239 kcal 
E) 976 kcal

Question 8

A solid sample at room temperature spontaneously sublimes forming a gas.This change in state is accompanied by which of the changes in the sample?

Accepted Answer

A) Entropy and energy decrease. 
B) Entropy and energy increase. 
C) Entropy decreases and energy increases. 
D) Entropy increases and energy decreases. 
A) Entropy and energy decrease. 
B) Entropy and energy increase. 
C) Entropy decreases and energy increases. 
D) Entropy increases and energy decreases.

Question 9

Calculate the equilibrium constant for the reaction below if a tank was found to contain 0.106 M O2,0.00652 M SO3 and 0.00129 M SO2.
2 SO3 (g)  
2 SO2 (g)+ O2 (g)

Accepted Answer

A) 6.78 × 10-2 
B) 1.34 × 10-2 
C) 4.15 × 10-3 
D) 4.35 × 10-2 
A) 6.78 × 10-2 
B) 1.34 × 10-2 
C) 4.15 × 10-3 
D) 4.35 × 10-2

Question 10

Consider the reaction:
A + 2 B  
2 C + D
The equilibrium expression for this reaction is:

Accepted Answer

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

Question 11

Match the following.
-A state in which the rate of the forward reaction is exactly equal to the rate of the reverse reaction

Accepted Answer

A) exergonic 
B) endergonic 
C) exothermic 
D) endothermic 
E) activation energy
F)chemical equilibrium 
A) exergonic 
B) endergonic 
C) exothermic 
D) endothermic 
E) activation energy
F)chemical equilibrium

Question 12

N2 + O2 → 2 NO ΔH = 43.2 kcal
Based on the reaction shown,which statement is true?

Accepted Answer

A) 43.2 kcal are consumed when 1.00 g of N2 reacts. 
B) 43.2 kcal are consumed when 1.00 g of O2 reacts. 
C) 43.2 kcal are consumed when 1.00 mole of O2 reacts. 
D) 43.2 kcal are produced when 1.00 mole of NO is produced. 
E) 43.2 kcal are consumed when 1.00 g of NO is produced. 
A) 43.2 kcal are consumed when 1.00 g of N2 reacts. 
B) 43.2 kcal are consumed when 1.00 g of O2 reacts. 
C) 43.2 kcal are consumed when 1.00 mole of O2 reacts. 
D) 43.2 kcal are produced when 1.00 mole of NO is produced. 
E) 43.2 kcal are consumed when 1.00 g of NO is produced.

Question 13

Select the correct figure to match the description.
-A fast reaction with a small positive free energy change

Accepted Answer

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

Question 14

2 SO2 (g)+ O2 (g)  
2 SO3 (g)+ heat K = 4.8 × 1027
Which statement about this system is not true?

Accepted Answer

A) At equilibrium SO3 is the predominant substance. 
B) Heating the system will cause breakdown of SO3. 
C) Adding SO2 will cause an increase in the amount of SO3. 
D) Removing O2 will cause an increase in the amount of SO3. 
E) The large value of K means that the reaction essentially goes to completion. 
A) At equilibrium SO3 is the predominant substance. 
B) Heating the system will cause breakdown of SO3. 
C) Adding SO2 will cause an increase in the amount of SO3. 
D) Removing O2 will cause an increase in the amount of SO3. 
E) The large value of K means that the reaction essentially goes to completion.

Question 15

Activation energy can best be described as

Accepted Answer

A) the energy level of the products. 
B) the maximum energy level of the reaction. 
C) the energy level of the reactants. 
D) the difference in energy between reactants and products. 
E) the difference in energy between reactants and the maximum energy. 
A) the energy level of the products. 
B) the maximum energy level of the reaction. 
C) the energy level of the reactants. 
D) the difference in energy between reactants and products. 
E) the difference in energy between reactants and the maximum energy.

Question 16

Which of the following conditions characterizes a system in a state of chemical equilibrium?

Accepted Answer

A) Concentrations of reactants and products are equal. 
B) Rate of forward reaction has dropped to zero. 
C) Reactants are being consumed at the same rate they are being produced. 
D) Reactant molecules no longer react with each other. 
E) Product concentrations are greater than reactant concentrations. 
A) Concentrations of reactants and products are equal. 
B) Rate of forward reaction has dropped to zero. 
C) Reactants are being consumed at the same rate they are being produced. 
D) Reactant molecules no longer react with each other. 
E) Product concentrations are greater than reactant concentrations.

Question 17

Match the following.
-A process or reaction that has a positive value of ΔG

Accepted Answer

A) exergonic 
B) endergonic 
C) exothermic 
D) endothermic 
E) activation energy
F)chemical equilibrium 
A) exergonic 
B) endergonic 
C) exothermic 
D) endothermic 
E) activation energy
F)chemical equilibrium

Question 18

All of the statements regarding the symbol "ΔH" are correct except

Accepted Answer

A) it represents the difference between the energy used in breaking bonds and the energy released in forming bonds in a chemical reaction. 
B) it can be called heat of reaction. 
C) it can be called enthalpy change. 
D) it can be called entropy change. 
E) it has a negative value for an exothermic reaction. 
A) it represents the difference between the energy used in breaking bonds and the energy released in forming bonds in a chemical reaction. 
B) it can be called heat of reaction. 
C) it can be called enthalpy change. 
D) it can be called entropy change. 
E) it has a negative value for an exothermic reaction.

Question 19

Which of the following processes involve an increase in entropy of the system?
I.Mothballs vaporize in a closet.
II.Blocks are assembled into a house.
III.Crystals grow from a sugar solution.
IV.Recyclable plastics are sorted.
V.Cake mix is manufactured from five basic ingredients.

Accepted Answer

A) II,IV 
B) I,II,III 
C) II,III,IV 
D) I,V 
E) I,III,V 
A) II,IV 
B) I,II,III 
C) II,III,IV 
D) I,V 
E) I,III,V

Question 20

If we add a catalyst to the following equation,CO + H2O + heat  
CO2 + H2,which way will the equilibrium shift?

Accepted Answer

A) to the left 
B) no effect 
C) to the right 
D) not enough information 
A) to the left 
B) no effect 
C) to the right 
D) not enough information

Exam 7: Chemical Reactions: Energy, rates, and Equilibrium

If heat is consumed during a reaction,the reaction is said to be ________.

-In the reaction energy diagrams shown,reaction A is ________,and it occurs ________ reaction B.

P4 (s)+ 10 Cl2 (g)→ 4 PCl5 (s) ΔH = -435.2 kcal Based on the reaction shown,which statement is true?

A reaction which is unfavorable with respect to entropy,but favorable with respect to enthalpy

A reaction that is spontaneous can be described as

Which process is not likely to be considered reversible?

For the reaction given below,what quantity of heat will be produced if 90.0 g of C3H8 are consumed in the reaction? C3H8 + 5 O2 → 3 CO2 + 4 H2O + 488 kcal

A solid sample at room temperature spontaneously sublimes forming a gas.This change in state is accompanied by which of the changes in the sample?

Calculate the equilibrium constant for the reaction below if a tank was found to contain 0.106 M O2,0.00652 M SO3 and 0.00129 M SO2. 2 SO3 (g) 2 SO2 (g)+ O2 (g)

Consider the reaction: A + 2 B 2 C + D The equilibrium expression for this reaction is:

Match the following. -A state in which the rate of the forward reaction is exactly equal to the rate of the reverse reaction

N2 + O2 → 2 NO ΔH = 43.2 kcal Based on the reaction shown,which statement is true?

Select the correct figure to match the description. -A fast reaction with a small positive free energy change

2 SO2 (g)+ O2 (g) 2 SO3 (g)+ heat K = 4.8 × 1027 Which statement about this system is not true?

Activation energy can best be described as

Which of the following conditions characterizes a system in a state of chemical equilibrium?

Match the following. -A process or reaction that has a positive value of ΔG

All of the statements regarding the symbol "ΔH" are correct except

Which of the following processes involve an increase in entropy of the system? I.Mothballs vaporize in a closet. II.Blocks are assembled into a house. III.Crystals grow from a sugar solution. IV.Recyclable plastics are sorted. V.Cake mix is manufactured from five basic ingredients.

If we add a catalyst to the following equation,CO + H2O + heat CO2 + H2,which way will the equilibrium shift?

Matter and Measurements

Atoms and the Periodic Table

Ionic Compounds

Molecular Compounds

Classification and Balancing of Chemical Reactions

Chemical Reactions: Mole and Mass Relationships

Gases, liquids, and Solids

Solutions

Acids and Bases

Nuclear Chemistry

Introduction to Organic Chemistry: Alkanes

Alkenes, alkynes, and Aromatic Compounds

Some Compounds With Oxygen, sulfur, or a Halogen

Amines

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Amino Acids and Proteins

Enzymes and Vitamins

The Generation of Biochemical Energy

Carbohydrates

Carbohydrate Metabolism

Lipids

Lipid Metabolism

Nucleic Acids and Protein Synthesis

Genomics

Protein and Amino Acid Metabolism

Chemical Messengers: Hormones, neurotransmitters, and Drugs

Body Fluids

Filters

-In the reaction energy diagrams shown,reaction A is ,and it occurs reaction B.

P₄ (s)+ 10 Cl₂ (g)→ 4 PCl₅(s) ΔH = -435.2 kcal Based on the reaction shown,which statement is true?

For the reaction given below,what quantity of heat will be produced if 90.0 g of C₃H₈ are consumed in the reaction? C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O + 488 kcal

Calculate the equilibrium constant for the reaction below if a tank was found to contain 0.106 M O₂,0.00652 M SO₃ and 0.00129 M SO₂. 2 SO₃ (g) 2 SO₂ (g)+ O₂ (g)

N₂ + O₂ → 2 NO ΔH = 43.2 kcal Based on the reaction shown,which statement is true?

2 SO₂ (g)+ O₂ (g) 2 SO₃ (g)+ heat K = 4.8 × 10²⁷ Which statement about this system is not true?

If we add a catalyst to the following equation,CO + H₂O + heat CO₂ + H₂,which way will the equilibrium shift?