Question 1

Which change to this reaction system would cause the equilibrium to shift to the right?
N2(g)+ 3 H2(g)  2 NH3(g)+ heat

Accepted Answer

A) addition of a catalyst 
B) addition of NH3(g) 
C) removal of H2(g) 
D) heating the system 
E) lowering the temperature 
A) addition of a catalyst 
B) addition of NH3(g) 
C) removal of H2(g) 
D) heating the system 
E) lowering the temperature

Question 2

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 3

Which of the following contains kinetic energy?

Accepted Answer

A) bicylce at the top of a hill 
B) ball laying on the ground 
C) a moving car 
D) a battery 
E) a piece of chocolate 
A) bicylce at the top of a hill 
B) ball laying on the ground 
C) a moving car 
D) a battery 
E) a piece of chocolate

Question 4

Entropy is used to

Accepted Answer

A) explain how energy is stored. 
B) explain how an exothermic reaction can become endothermic. 
C) indicate the disorder of a system. 
D) explain why most chemical reactions are exothermic. 
E) none of the above 
A) explain how energy is stored. 
B) explain how an exothermic reaction can become endothermic. 
C) indicate the disorder of a system. 
D) explain why most chemical reactions are exothermic. 
E) none of the above

Question 5

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 6

For the following reaction,increasing the pressure will cause the equilibrium to
2 SO2(g)+ O2(g)  2 SO3(g)+ heat

Accepted Answer

A) shift to the right,towards products. 
B) shift to the left,towards reactants. 
C) remain unchanged,but the reaction mixture will get warmer. 
D) remain unchanged,but the reaction mixture will get cooler. 
E) Pressure has no effect on equilibrium. 
A) shift to the right,towards products. 
B) shift to the left,towards reactants. 
C) remain unchanged,but the reaction mixture will get warmer. 
D) remain unchanged,but the reaction mixture will get cooler. 
E) Pressure has no effect on equilibrium.

Question 7

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.

Question 8

-For a chemical reaction to occur,all of the following must happen except

Accepted Answer

A) chemical bonds in the reactants must break. 
B) reactant particles must collide with enough energy for change to occur. 
C) reactant particles must collide with the correct orientation. 
D) a large enough number of collisions must occur. 
E) chemical bonds in the products must form. 
A) chemical bonds in the reactants must break. 
B) reactant particles must collide with enough energy for change to occur. 
C) reactant particles must collide with the correct orientation. 
D) a large enough number of collisions must occur. 
E) chemical bonds in the products must form.

Question 9

Which of the following statements can be assumed to be true about how reactions occur?

Accepted Answer

A) Catalysts must be present in the reaction. 
B) Energy must be absorbed as the reaction proceeds. 
C) Reactant particles must collide with each other. 
D) More than one statement can be true. 
A) Catalysts must be present in the reaction. 
B) Energy must be absorbed as the reaction proceeds. 
C) Reactant particles must collide with each other. 
D) More than one statement can be true.

Question 10

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

Accepted Answer

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

Question 11

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

Accepted Answer

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

Question 12

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 13

Activation energy can best be described as the

Accepted Answer

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

Question 14

Which factors would decrease the rate of a reaction?
I.Lowering the temperature
II.Increasing the concentration of reactants
III.Adding a catalyst

Accepted Answer

A) I only 
B) II only 
C) III only 
D) II and III 
E) I and III 
A) I only 
B) II only 
C) III only 
D) II and III 
E) I and III

Question 15

-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 16

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.

Question 17

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 18

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 19

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 20

Given the following reaction,the equilibrium expression will be:
C(s)+ 2 H2(g)  CH4(g)

Accepted Answer

A)  [CH4]/[C] [H2]2 
B) k[C][H2] 
C) [CH4]/[H2]2 
D) [H2]2[C]/[CH4] 
E)  [CH4][C] [H2]2 
A)  [CH4]/[C] [H2]2 
B) k[C][H2] 
C) [CH4]/[H2]2 
D) [H2]2[C]/[CH4] 
E)  [CH4][C] [H2]2

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

Which change to this reaction system would cause the equilibrium to shift to the right? N2(g)+ 3 H2(g) 2 NH3(g)+ heat

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?

Which of the following contains kinetic energy?

Entropy is used to

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

For the following reaction,increasing the pressure will cause the equilibrium to 2 SO2(g)+ O2(g) 2 SO3(g)+ heat

A rapid reaction is distinguished by

-For a chemical reaction to occur,all of the following must happen except

Which of the following statements can be assumed to be true about how reactions occur?

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

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

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 ________.

Activation energy can best be described as the

Which factors would decrease the rate of a reaction? I.Lowering the temperature II.Increasing the concentration of reactants III.Adding a catalyst

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

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 negative free energy change

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 ________.

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

Given the following reaction,the equilibrium expression will be: C(s)+ 2 H2(g) CH4(g)

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

Aldehydes and Ketones

Amines

Carboxylic Acids and Their Derivatives

Amino Acids and Proteins

Enzymes and Vitamins

Carbohydrates

The Generation of Biochemical Energy

Carbohydrate Metabolism

Lipids

Lipid Metabolism

Protein and Amino Acid Metabolism

Nucleic Acids and Protein Synthesis

Genomics

Chemical Messengers: Hormones, neurotransmitters, and Drugs

Body Fluids

Filters

Which change to this reaction system would cause the equilibrium to shift to the right? N₂(g)+ 3 H₂(g) 2 NH₃(g)+ heat

For the following reaction,increasing the pressure will cause the equilibrium to 2 SO₂(g)+ O₂(g) 2 SO₃(g)+ heat

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 .

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

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 .

Given the following reaction,the equilibrium expression will be: C(s)+ 2 H₂(g) CH₄(g)