Question 1

A process or reaction which takes in heat from the surroundings is said to be

Accepted Answer

A) conservative. 
B) endothermic. 
C) exothermic. 
D) isothermal. 
E) endergonic. 
A) conservative. 
B) endothermic. 
C) exothermic. 
D) isothermal. 
E) endergonic. B

Question 2

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

Accepted Answer

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

Question 3

Which statement best describes the way a catalyst works?

Accepted Answer

A) It decreases the value of ΔH. 
B) It increases the value of ΔH. 
C) It decreases the value of Eact. 
D) It increases the value of Eact. 
E) It increases the value of ΔG. 
A) It decreases the value of ΔH. 
B) It increases the value of ΔH. 
C) It decreases the value of Eact. 
D) It increases the value of Eact. 
E) It increases the value of ΔG. C

Question 4

Consider the endothermic reaction:
N2 (g)+ 2 H2 (g)→ N2H4 (l)
The entropy change of this reaction is ________ and the enthalpy change is ________,so at a very high temperature,this reaction is probably ________.

Accepted Answer

A) favorable; unfavorable; nonspontaneous 
B) favorable; unfavorable; spontaneous 
C) unfavorable; unfavorable; spontaneous 
D) unfavorable; unfavorable; nonspontaneous 
E) unfavorable; favorable; spontaneous 
A) favorable; unfavorable; nonspontaneous 
B) favorable; unfavorable; spontaneous 
C) unfavorable; unfavorable; spontaneous 
D) unfavorable; unfavorable; nonspontaneous 
E) unfavorable; favorable; spontaneous

Question 5

Consider the reaction shown:
P4 (s)+ 10 Cl2 (g)→ 4 PCl5 (s)+ 452 kcal
When 50.00 g of P4 react,________ kcal will be ________.

Accepted Answer

A) 182.4; consumed 
B) 452; produced 
C) 729.7; produced 
D) 182.4; produced 
E) 452; consumed 
A) 182.4; consumed 
B) 452; produced 
C) 729.7; produced 
D) 182.4; produced 
E) 452; consumed

Question 6

-In the reaction energy diagrams shown,reaction B 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 7

Match the following.
-A process or reaction which consumes heat

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 8

The concept of free energy allows prediction of spontaneity of a process by considering the changes in ________ and ________ during the process.

Accepted Answer

A) enthalpy; entropy 
B) enthalpy; mass 
C) entropy; mass 
D) enthalpy; temperature 
E) entropy; temperature 
A) enthalpy; entropy 
B) enthalpy; mass 
C) entropy; mass 
D) enthalpy; temperature 
E) entropy; temperature

Question 9

2 Al2O3 (s)→ 4 Al (s)+ 3 O2 (g) ΔG = +138 kcal
Consider the contribution of entropy to the spontaneity of this reaction.As written,the reaction is ________,and the entropy of the system ________.

Accepted Answer

A) spontaneous; increases 
B) spontaneous; decreases 
C) non-spontaneous; increases 
D) non-spontaneous; decreases 
E) non-spontaneous; does not change 
A) spontaneous; increases 
B) spontaneous; decreases 
C) non-spontaneous; increases 
D) non-spontaneous; decreases 
E) non-spontaneous; does not change

Question 10

A reaction is said to be ________ if the bonds formed during the reaction are stronger than the bonds broken.

Accepted Answer

A) exothermic 
B) endothermic 
C) exergonic 
D) endergonic 
E) spontaneous 
A) exothermic 
B) endothermic 
C) exergonic 
D) endergonic 
E) spontaneous

Question 11

Consider the reaction shown:
304.0 kcal + 4 PCl3 (l)→ P4 (s)+ 6 Cl2 (g)
When 50.00 g of PCl3 react,________ kcal will be ________.

Accepted Answer

A) 304.0; produced 
B) 27.67; produced 
C) 304.0; consumed 
D) 110.7; consumed 
E) 27.67; consumed 
A) 304.0; produced 
B) 27.67; produced 
C) 304.0; consumed 
D) 110.7; consumed 
E) 27.67; consumed

Question 12

Select the correct figure to match the description.
-A slow reaction with a negative free energy change

Accepted Answer

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

Question 13

To simplify comparisons,the energy value of fuels is expressed in units of

Accepted Answer

A) kcal. 
B) kcal/mol. 
C) kcal/g. 
D) kcal/L. 
E) some other unit 
A) kcal. 
B) kcal/mol. 
C) kcal/g. 
D) kcal/L. 
E) some other unit

Question 14

Consider the reaction:
2 CO (g)+ O2 (g)  
2 CO2 (g)
The equilibrium expression for this reaction is:

Accepted Answer

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

Question 15

The scientific principle which explains the observation that the amount of heat transfer accompanying a change in one direction is numerically equal but opposite in sign to the amount of heat transfer in the opposite direction is

Accepted Answer

A) the Law of Conservation of Energy. 
B) the Law of Conservation of Mass. 
C) the Law of Conservation of Mass and Energy. 
D) the Law of Definite Proportions. 
E) Avogadro's Law. 
A) the Law of Conservation of Energy. 
B) the Law of Conservation of Mass. 
C) the Law of Conservation of Mass and Energy. 
D) the Law of Definite Proportions. 
E) Avogadro's Law.

Question 16

When a reaction system is at equilibrium

Accepted Answer

A) there is no more chemistry happening. 
B) the amounts of reactants and products are exactly equal. 
C) the reaction rate in the forward direction is at a maximum. 
D) the reaction rate in the reverse direction is at a minimum. 
E) the rates of the reaction in the forward and reverse directions are exactly equal. 
A) there is no more chemistry happening. 
B) the amounts of reactants and products are exactly equal. 
C) the reaction rate in the forward direction is at a maximum. 
D) the reaction rate in the reverse direction is at a minimum. 
E) the rates of the reaction in the forward and reverse directions are exactly equal.

Question 17

Consider the reaction shown:
C3H8 + 5 O2 → 3 CO2 + 4 H2O + 488 kcal
We can say that this reaction is ________ and that the sign of ΔH is ________.

Accepted Answer

A) endothermic; positive 
B) exothermic; positive 
C) endothermic; negative 
D) exothermic; negative 
E) exothermic; neither positive nor negative 
A) endothermic; positive 
B) exothermic; positive 
C) endothermic; negative 
D) exothermic; negative 
E) exothermic; neither positive nor negative

Question 18

Consider the reaction shown:
452 kcal + 4 PCl5 (s)→ P4 (s)+ 10 Cl2 (g)
This reaction is ________ because the sign of ΔH is ________.

Accepted Answer

A) endothermic; positive 
B) exothermic; positive 
C) endothermic; negative 
D) exothermic; negative 
E) exothermic; neither positive nor negative 
A) endothermic; positive 
B) exothermic; positive 
C) endothermic; negative 
D) exothermic; negative 
E) exothermic; neither positive nor negative

Question 19

Select the correct figure to match the description.
-A slow reaction with a large negative free energy change

Accepted Answer

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

Question 20

A rapid reaction is distinguished by

Accepted Answer

A) being unaffected by catalysts. 
B) having a large heat of reaction. 
C) having a small heat of reaction. 
D) having a large value of activation energy. 
E) having a small value of activation energy. 
A) being unaffected by catalysts. 
B) having a large heat of reaction. 
C) having a small heat of reaction. 
D) having a large value of activation energy. 
E) having a small value of activation energy.

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

A process or reaction which takes in heat from the surroundings is said to be

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

Which statement best describes the way a catalyst works?

Consider the endothermic reaction: N2 (g)+ 2 H2 (g)→ N2H4 (l) The entropy change of this reaction is ________ and the enthalpy change is ________,so at a very high temperature,this reaction is probably ________.

Consider the reaction shown: P4 (s)+ 10 Cl2 (g)→ 4 PCl5 (s)+ 452 kcal When 50.00 g of P4 react,________ kcal will be ________.

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

Match the following. -A process or reaction which consumes heat

The concept of free energy allows prediction of spontaneity of a process by considering the changes in ________ and ________ during the process.

2 Al2O3 (s)→ 4 Al (s)+ 3 O2 (g) ΔG = +138 kcal Consider the contribution of entropy to the spontaneity of this reaction.As written,the reaction is ________,and the entropy of the system ________.

A reaction is said to be ________ if the bonds formed during the reaction are stronger than the bonds broken.

Consider the reaction shown: 304.0 kcal + 4 PCl3 (l)→ P4 (s)+ 6 Cl2 (g) When 50.00 g of PCl3 react,________ kcal will be ________.

Select the correct figure to match the description. -A slow reaction with a negative free energy change

To simplify comparisons,the energy value of fuels is expressed in units of

Consider the reaction: 2 CO (g)+ O2 (g) 2 CO2 (g) The equilibrium expression for this reaction is:

The scientific principle which explains the observation that the amount of heat transfer accompanying a change in one direction is numerically equal but opposite in sign to the amount of heat transfer in the opposite direction is

When a reaction system is at equilibrium

Consider the reaction shown: C3H8 + 5 O2 → 3 CO2 + 4 H2O + 488 kcal We can say that this reaction is ________ and that the sign of ΔH is ________.

Consider the reaction shown: 452 kcal + 4 PCl5 (s)→ P4 (s)+ 10 Cl2 (g) This reaction is ________ because the sign of ΔH is ________.

Select the correct figure to match the description. -A slow reaction with a large negative free energy change

A rapid reaction is distinguished by

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

Consider the endothermic reaction: N₂ (g)+ 2 H₂ (g)→ N₂H₄ (l) The entropy change of this reaction is and the enthalpy change is ,so at a very high temperature,this reaction is probably .

Consider the reaction shown: P₄ (s)+ 10 Cl₂ (g)→ 4 PCl₅ (s)+ 452 kcal When 50.00 g of P₄ react, kcal will be .

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

The concept of free energy allows prediction of spontaneity of a process by considering the changes in and during the process.

2 Al₂O₃ (s)→ 4 Al (s)+ 3 O₂ (g) ΔG = +138 kcal Consider the contribution of entropy to the spontaneity of this reaction.As written,the reaction is ,and the entropy of the system .

Consider the reaction shown: 304.0 kcal + 4 PCl₃ (l)→ P₄ (s)+ 6 Cl₂ (g) When 50.00 g of PCl₃ react, kcal will be .

Consider the reaction: 2 CO (g)+ O₂ (g) 2 CO₂ (g) The equilibrium expression for this reaction is:

Consider the reaction shown: C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O + 488 kcal We can say that this reaction is and that the sign of ΔH is .

Consider the reaction shown: 452 kcal + 4 PCl₅ (s)→ P₄ (s)+ 10 Cl₂ (g) This reaction is because the sign of ΔH is .