Question 1

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

Question 2

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

Question 3

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)

Question 4

In order to determine if a reaction is at equilibrium which of the following must be true?

Accepted Answer

A)  The concentrations of the reactants and products must be equal.
B)  The concentration of the products must be greater than the reactants.
C)  The forward and reverse reactions have stopped.
D)  The rate at which the forward and reverse reactions are proceeding are equal.
E)  All of the above are true.

Question 5

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

Question 6

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

Accepted Answer

A)  
B)  
C)  
D)  
E)

Question 7

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.

Question 8

Consider the reaction shown:
N2 + O2 → 2 NO ΔH = 43.2 kcal
When 50.0 g of N2 react,________ kcal will be ________.

Accepted Answer

A)  43.2;produced
B)  77.1;consumed
C)  77.1;produced
D)  2160;consumed
E)  2160;produced

Question 9

In the reaction A + B → AB,which of the following will not increase the rate?

Accepted Answer

A)  adding A
B)  adding B
C)  increasing the temperature
D)  decreasing the temperature
E)  adding a catalyst

Question 10

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 E

Question 11

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.

Question 12

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

Accepted Answer

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

Question 13

-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

Question 14

Which of the following contains potential energy?

Accepted Answer

A)  person riding a bicycle
B)  a book on a table
C)  a bouncing ball
D)  a kid jumping rope
E)  dancing

Question 15

Which of the following will affect all reaction rates?

Accepted Answer

A)  the temperature of the reactants
B)  the concentrations of the reactants
C)  the presence of a catalyst
D)  All are correct.

Question 16

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.

Question 17

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

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.

Question 18

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) 2,0.00652 M SO3, and 0.00129 M SO2. 2 SO3(g)  2 SO2(g) + O2(g)  A) 6.78 × 10-2 B) 1.34 × 10-2 C) 4.15 × 10-3 D) 4.35 × 10-2 E) 9.66 × 10-3" class="answers-bank-image d-inline" rel="preload" >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
E)  9.66 × 10-3

Question 19

Which of the following can affect the activation energy of a reaction?

Accepted Answer

A)  increase in concentration of products
B)  increase in concentration of reactants
C)  surface area of reactants
D)  use of a catalyst
E)  temperature of the reaction

Question 20

Write the equilibrium expression for the following reaction:
4 HNO3(l) 3(l)  4 NO2(g) + 2 H2O(g) + O2(g)  A) [NO2]4 [H2O]2 [O2]/[HNO3]4 B) 1/[NO2]4 [H2O]2 [O2] C) [HNO3]4/[NO2]4 [H2O]2 [O2] D) [NO2]4 [H2O]2 [O2] E) [NO2]4 + [H2O]2 + [O2]" class="answers-bank-image d-inline" rel="preload" >4 NO2(g) + 2 H2O(g) + O2(g)

Accepted Answer

A)  [NO2]4 [H2O]2 [O2]/[HNO3]4
B)  1/[NO2]4 [H2O]2 [O2]
C)  [HNO3]4/[NO2]4 [H2O]2 [O2]
D)  [NO2]4 [H2O]2 [O2]
E)  [NO2]4 + [H2O]2 + [O2] D

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

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

In order to determine if a reaction is at equilibrium which of the following must be true?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedA

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

Correct AnswerverifiedShow Answer

When a reaction system is at equilibrium

Correct AnswerverifiedShow Answer

Consider the reaction shown: N2 + O2 → 2 NO ΔH = 43.2 kcal When 50.0 g of N2 react,________ kcal will be ________.

Correct AnswerverifiedShow Answer

In the reaction A + B → AB,which of the following will not increase the rate?

Correct AnswerverifiedShow Answer

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 ________.

Correct AnswerverifiedE

Which statement best describes the way a catalyst works?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following contains potential energy?

Correct AnswerverifiedShow Answer

Which of the following will affect all reaction rates?

Correct AnswerverifiedShow Answer

A reaction that is spontaneous can be described as

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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)

Correct AnswerverifiedShow Answer

Which of the following can affect the activation energy of a reaction?

Correct AnswerverifiedShow Answer

Write the equilibrium expression for the following reaction: 4 HNO3(l) 4 NO2(g) + 2 H2O(g) + O2(g)

Correct AnswerverifiedD

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

Correct Answer
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A

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Consider the reaction shown: N₂ + O₂ → 2 NO ΔH = 43.2 kcal When 50.0 g of N₂ react, kcal will be .

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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 .

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E

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

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

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Calculate the equilibrium constant for the reaction below if a tank was found to contain 0.106 M O₂,0.00652 M SO_3, and 0.00129 M SO₂. 2 SO₃(g) 2 SO₂(g) + O₂(g)

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Write the equilibrium expression for the following reaction: 4 HNO₃(l) 4 NO₂(g) + 2 H₂O(g) + O₂(g)

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D