Question 1

Hydrofluoric acid,HF,dissociates in water according to the following reaction.
HF(aq)$\leftrightarrows$  H+(aq)+ F-(aq)Kc = 3.5 $\times$10-4
What is the concentration of H+ in a 0.0100 M solution of HF?

Accepted Answer

Use the quadratic fo...

Question 2

If K for a reaction is large,_________

Accepted Answer

A)  " Δ\DeltaΔ G ∘\circ∘ is definitely negative."
B)  " Δ\DeltaΔ G ∘\circ∘ is definitely positive."
C)  " Δ\DeltaΔ G ∘\circ∘ is equal to zero."
D)  " Δ\DeltaΔ G is definitely negative."
E)  " Δ\DeltaΔ G is definitely positive." F) C) and D)
G) A) and B)

Question 3

For the equilibrium (CH3) 3CCl(g)  ⇆\leftrightarrows⇆   (CH3) 2C = CH2(g) + HCl(g) ,Kp = 3.45 at 500 K.At a given point,the partial pressures of the gases are 3) 3CCl(g)  \leftrightarrows   (CH3) 2C = CH2(g) + HCl(g) ,Kp = 3.45 at 500 K.At a given point,the partial pressures of the gases are   = 0.810 atm and   = 0.190 atm.Which of the following statements is true? A) Q  K so the reaction will consume products to make more reactants. C) Q = K so the system is at equilibrium. D) The value of K will decrease until it is equal to Q. E) The value of K will increase until it is equal to Q. " class="answers-bank-image d-inline" rel="preload" > = 0.810 atm and 3) 3CCl(g)  \leftrightarrows   (CH3) 2C = CH2(g) + HCl(g) ,Kp = 3.45 at 500 K.At a given point,the partial pressures of the gases are   = 0.810 atm and   = 0.190 atm.Which of the following statements is true? A) Q  K so the reaction will consume products to make more reactants. C) Q = K so the system is at equilibrium. D) The value of K will decrease until it is equal to Q. E) The value of K will increase until it is equal to Q. " class="answers-bank-image d-inline" rel="preload" > = 0.190 atm.Which of the following statements is true?

Accepted Answer

A)  Q 
B)  Q > K so the reaction will consume products to make more reactants.
C)  Q = K so the system is at equilibrium.
D)  The value of K will decrease until it is equal to Q.
E)  The value of K will increase until it is equal to Q. F) A) and C)
G) B) and E)

Question 4

For the equilibrium CO2(g) + N2(g)  ⇆\leftrightarrows⇆   CO(g) + N2O(g) ,the forward and reverse rate constants at 1200 K are 9.1  ×	imes×  10-11 M -1 s-1 and 1.5  ×	imes×  105 M -1 s-1,respectively.What is the value of the equilibrium constant for CO(g) + N2O(g)  ⇆\leftrightarrows⇆  CO2(g) + N2(g) ?

Accepted Answer

A)  1.6  ×	imes×  1015
B)  1.4  ×	imes×  10-5
C)  6.1  ×	imes×  10-16
D)  7.1  ×	imes×  104
E)  1.0 F) A) and B)
G) B) and E)

Question 5

Chromic acid is a diprotic acid: H2CrO4(aq)  ⇆\leftrightarrows⇆  HCrO4-(aq) + H+(aq) Ka1 = 3.55
HCrO4-(aq)  ⇆\leftrightarrows⇆  CrO42-(aq) + H+(aq) Ka2 = 3.36  ×	imes×  10-7
Calculate the theoretical value of the equilibrium constant for 2 HCrO4-(aq)  ⇆\leftrightarrows⇆   H2CrO4(aq) + CrO42-(aq) .

Accepted Answer

A)  1.05  ×	imes×  107
B)  1.19  ×	imes×  10-6
C)  9.46  ×	imes×  10-8
D)  8.38  ×	imes×  105
E)  0.282 F) B) and D)
G) C) and D)

Question 6

A perturbation or stress to a chemical reaction at equilibrium _________

Accepted Answer

A)  increases the free energy of the system.
B)  decreases the free energy of the system.
C)  neither increases nor decreases the free energy of the system.
D)  may increase or decrease the free energy of the system depending on the nature of the stress.
E)  causes the free energy of the system to become zero.F) All of the above
G) B) and D)

Question 7

An increase in the number of moles of gas as the reaction goes from reactants to products in a gas-phase equilibrium results in __________

Accepted Answer

A)  Kp > Kc.
B)  Kp c.
C)  Kp = Kc.
D)  Kp + Kc = (RT)  Δ\DeltaΔ n.
E)  KpKc = (RT)  Δ\DeltaΔ n. F) C) and D)
G) A) and E)

Question 8

Addition of reactants to a chemical reaction in solution or gas phase at equilibrium results in __________

Accepted Answer

A)  an increase in K and a shift in equilibrium to produce more products.
B)  an increase in K and a shift in equilibrium to produce more reactants.
C)  a decrease in K and a shift in equilibrium to produce more products.
D)  a decrease in K and a shift in equilibrium to produce more reactants.
E)  no change in K and a shift in equilibrium to produce more products.F) All of the above
G) B) and C)

Question 9

A chemical equilibrium 2 A  ⇆\leftrightarrows⇆  B has a forward rate constant,kf = 10 M -1 s-1,and a reverse rate constant,kr = 5 s-1.What is the value of the equilibrium constant for this system?

Accepted Answer

A)  0.5
B)  2
C)  20
D)  0.05
E)  5 F) B) and D)
G) C) and D)

Question 10

The law of mass action is a result of __________

Accepted Answer

A)  the law of conservation of matter.
B)  the law of conservation of energy.
C)  kinetics of reversible reactions.
D)  limiting reagent stoichiometry.
E)  the third law of thermodynamics.F) A) and E)
G) A) and B)

Question 11

For the equilibrium H2O(g) + CH4(g)  ⇆\leftrightarrows⇆   CO(g) + 3 H2(g) ,Kp = 1.61  ×	imes×  10-5 at 1400 K.At a given point,the partial pressures of the gases are 2O(g) + CH4(g)  \leftrightarrows   CO(g) + 3 H2(g) ,Kp = 1.61  	imes  10-5 at 1400 K.At a given point,the partial pressures of the gases are   = 0.264 atm,   = 0.126 atm,   = 0.0382 atm,and   = 0.0974 atm.Which of the following statements is true? A) Q  K so the reaction will consume products to make more reactants. C) Q = K so the system is at equilibrium. D) The value of K will decrease until it is equal to Q. E) The value of K will increase until it is equal to Q. " class="answers-bank-image d-inline" rel="preload" > = 0.264 atm, 2O(g) + CH4(g)  \leftrightarrows   CO(g) + 3 H2(g) ,Kp = 1.61  	imes  10-5 at 1400 K.At a given point,the partial pressures of the gases are   = 0.264 atm,   = 0.126 atm,   = 0.0382 atm,and   = 0.0974 atm.Which of the following statements is true? A) Q  K so the reaction will consume products to make more reactants. C) Q = K so the system is at equilibrium. D) The value of K will decrease until it is equal to Q. E) The value of K will increase until it is equal to Q. " class="answers-bank-image d-inline" rel="preload" > = 0.126 atm, 2O(g) + CH4(g)  \leftrightarrows   CO(g) + 3 H2(g) ,Kp = 1.61  	imes  10-5 at 1400 K.At a given point,the partial pressures of the gases are   = 0.264 atm,   = 0.126 atm,   = 0.0382 atm,and   = 0.0974 atm.Which of the following statements is true? A) Q  K so the reaction will consume products to make more reactants. C) Q = K so the system is at equilibrium. D) The value of K will decrease until it is equal to Q. E) The value of K will increase until it is equal to Q. " class="answers-bank-image d-inline" rel="preload" > = 0.0382 atm,and 2O(g) + CH4(g)  \leftrightarrows   CO(g) + 3 H2(g) ,Kp = 1.61  	imes  10-5 at 1400 K.At a given point,the partial pressures of the gases are   = 0.264 atm,   = 0.126 atm,   = 0.0382 atm,and   = 0.0974 atm.Which of the following statements is true? A) Q  K so the reaction will consume products to make more reactants. C) Q = K so the system is at equilibrium. D) The value of K will decrease until it is equal to Q. E) The value of K will increase until it is equal to Q. " class="answers-bank-image d-inline" rel="preload" > = 0.0974 atm.Which of the following statements is true?

Accepted Answer

A)  Q 
B)  Q > K so the reaction will consume products to make more reactants.
C)  Q = K so the system is at equilibrium.
D)  The value of K will decrease until it is equal to Q.
E)  The value of K will increase until it is equal to Q. F) C) and D)
G) A) and D)

Question 12

Two students measure the equilibrium constant for the same chemical reaction.One student finds Kc to be 130; the other calculates Kc to be 11.4.The instructor checks their results and says they are both correct.Which of the following is a plausible explanation?

Accepted Answer

A)  The values vary according to the way the measurement is made.One student must have measured product concentrations,while the second measured reactant concentrations.
B)  The values vary according to the starting conditions of the reaction prior to equilibrium.One student must have started with all reactants,while the second must have started with all products.
C)  The values vary according to the stoichiometric coefficients that are used.The balancing coefficients that the first student used must have been twice those that the second used.
D)  The values vary according to direction of the reaction.One student must have used the reverse reaction.
E)  The instructor must have made a mistake,as the equilibrium constant for a reaction must always be the same.F) B) and E)
G) D) and E)

Question 13

As T approaches infinity,ln K approaches __________

Accepted Answer

A)  infinity.
B)  zero.
C)    .
D)    .
E)    .F) A) and B)
G) C) and D)

Question 14

Write the equilibrium expression for the following reaction: CH4(g) + 2 H2S(g)  ⇆\leftrightarrows⇆  CS2(g) + 4 H2(g) .

Accepted Answer

A)   4(g) + 2 H2S(g)  \leftrightarrows  CS2(g) + 4 H2(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" >
B)   4(g) + 2 H2S(g)  \leftrightarrows  CS2(g) + 4 H2(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" >
C)   4(g) + 2 H2S(g)  \leftrightarrows  CS2(g) + 4 H2(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" >
D)   4(g) + 2 H2S(g)  \leftrightarrows  CS2(g) + 4 H2(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" >
E)   4(g) + 2 H2S(g)  \leftrightarrows  CS2(g) + 4 H2(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" > F) A) and C)
G) A) and D)

Question 15

An equilibrium that strongly favors products has __________

Accepted Answer

A)  a value of K 
B)  a value of K>>1.
C)  a value of Q>>1.
D)  a value of Q
E)  K = Q.F) A) and C)
G) A) and B)

Question 16

Students often write expressions for the equilibrium constant Kc and reaction quotient Qc in exactly the same way.To avoid confusion,remember that Kc uses concentrations under __________ conditions while Qc uses concentrations under __________ conditions.

Accepted Answer

Question 17

For the equilibrium NO2(g) + O2(g)  ⇆\leftrightarrows⇆   NO(g) + O3(g) ,the equilibrium constant at 300.0 K is approximately 2.9  ×	imes×  10-35,and the rate constant of the reverse reaction is approximately 8.5  ×	imes×  106 M -1 s-1.What is the value of the forward rate constant?

Accepted Answer

A)  2.1  ×	imes× 10-21 M -1 s-1
B)  3.4  ×	imes×  10-42 M -1 s-1
C)  2.5  ×	imes×  10-28 M -1 s-1
D)  4.1  ×	imes×  1027 M -1 s-1
E)  1.0 M -1 s-1 F) All of the above
G) A) and D)

Question 18

For the equilibrium 2 ClO(g)  ⇆\leftrightarrows⇆   Cl2O2(g) ,Kc = 4.96  ×	imes×  1011 at 253 K.What is Kc for the equilibrium 2O2(g) ,Kc = 4.96  	imes  1011 at 253 K.What is Kc for the equilibrium   Cl2O2(g)  \leftrightarrows   ClO(g) ? A) 7.04  	imes  105 B) 2.02  	imes  10-12 C) 9.90 	imes  1011 D) 1.01  	imes  10-12 E) 1.42  	imes  10-6 " class="answers-bank-image d-inline" rel="preload" > Cl2O2(g)  ⇆\leftrightarrows⇆   ClO(g) ?

Accepted Answer

A)  7.04  ×	imes×  105
B)  2.02  ×	imes×  10-12
C)  9.90 ×	imes×  1011
D)  1.01  ×	imes×  10-12
E)  1.42  ×	imes×  10-6 F) A) and B)
G) C) and D)

Question 19

Identify the equilibrium expression for the following reaction: CH3CHO(g)  ⇆\leftrightarrows⇆  CH4(g) + CO(g) .

Accepted Answer

A)   3CHO(g)  \leftrightarrows  CH4(g) + CO(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" >
B)   3CHO(g)  \leftrightarrows  CH4(g) + CO(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" >
C)   3CHO(g)  \leftrightarrows  CH4(g) + CO(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" >
D)   3CHO(g)  \leftrightarrows  CH4(g) + CO(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" >
E)   3CHO(g)  \leftrightarrows  CH4(g) + CO(g) . 
A)     
B)     
C)     
D)     
E)     " class="answers-bank-image d-inline" rel="preload" > F) B) and E)
G) B) and D)

Question 20

Which of the following lists quantities that may have only positive values?

Accepted Answer

A)  "K,Q,and S ∘\circ∘ "
B)  " Δ\DeltaΔ G, Δ\DeltaΔ H,and  Δ\DeltaΔ S"
C)  "ln K and ln Q"
D)  "K and  Δ\DeltaΔ G ∘\circ∘ '
E)  none of the above F) A) and B)
G) A) and C)

Exam 14: Chemical Equilibrium-Equal but Opposite Reaction Rates

A perturbation or stress to a chemical reaction at equilibrium _________

Correct Answer
verified

As T approaches infinity,ln K approaches __________

Correct Answer
verified

If K for a reaction is large,_________

Correct Answer
verified

Which of the following lists quantities that may have only positive values?

Correct Answer
verified

The law of mass action is a result of __________

Correct Answer
verified

Identify the equilibrium expression for the following reaction: CH₃CHO(g) $\leftrightarrows$ CH₄(g) + CO(g) .

Correct Answer
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Correct Answer
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Write the equilibrium expression for the following reaction: CH₄(g) + 2 H₂S(g) $\leftrightarrows$ CS₂(g) + 4 H₂(g) .

Correct Answer
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Correct Answer
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An equilibrium that strongly favors products has __________

Correct Answer
verified

Correct Answer
verified

Two students measure the equilibrium constant for the same chemical reaction.One student finds K_c to be 130; the other calculates K_c to be 11.4.The instructor checks their results and says they are both correct.Which of the following is a plausible explanation?

Correct Answer
verified

An increase in the number of moles of gas as the reaction goes from reactants to products in a gas-phase equilibrium results in __________

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A chemical equilibrium 2A $\leftrightarrows$ B has a forward rate constant,k_f = 10 M ^-¹s^-¹,and a reverse rate constant,k_r = 5 s^-¹.What is the value of the equilibrium constant for this system?

Correct Answer
verified

Students often write expressions for the equilibrium constant K_c and reaction quotient Q_c in exactly the same way.To avoid confusion,remember that K_c uses concentrations under __________ conditions while Q_c uses concentrations under __________ conditions.

Correct Answer
verified

Hydrofluoric acid,HF,dissociates in water according to the following reaction. HF(aq) $\leftrightarrows$ H⁺(aq)+ F^-(aq)K_c = 3.5 $\times$ 10^-⁴ What is the concentration of H⁺ in a 0.0100 M solution of HF?

Correct Answer
verified
Use the quadratic fo...
View Answer

For the equilibrium NO₂(g) + O₂(g) $\leftrightarrows$ NO(g) + O₃(g) ,the equilibrium constant at 300.0 K is approximately 2.9 $\times$ 10^-35,and the rate constant of the reverse reaction is approximately 8.5 $\times$ 10⁶ M ^-¹s^-¹.What is the value of the forward rate constant?

Correct Answer
verified

Addition of reactants to a chemical reaction in solution or gas phase at equilibrium results in __________

Correct Answer
verified

Exam 14: Chemical Equilibrium-Equal but Opposite Reaction Rates

A perturbation or stress to a chemical reaction at equilibrium _________

Correct AnswerverifiedShow Answer

As T approaches infinity,ln K approaches __________

Correct AnswerverifiedShow Answer

If K for a reaction is large,_________

Correct AnswerverifiedShow Answer

Which of the following lists quantities that may have only positive values?

Correct AnswerverifiedShow Answer

The law of mass action is a result of __________

Correct AnswerverifiedShow Answer

Identify the equilibrium expression for the following reaction: CH3CHO(g) ⇆\leftrightarrows⇆ CH4(g) + CO(g) .

Correct AnswerverifiedShow Answer

For the equilibrium H2O(g) + CH4(g) ⇆\leftrightarrows⇆ CO(g) + 3 H2(g) ,Kp = 1.61 ×\times× 10-5 at 1400 K.At a given point,the partial pressures of the gases are = 0.264 atm, = 0.126 atm, = 0.0382 atm,and = 0.0974 atm.Which of the following statements is true?

Correct AnswerverifiedShow Answer

Write the equilibrium expression for the following reaction: CH4(g) + 2 H2S(g) ⇆\leftrightarrows⇆ CS2(g) + 4 H2(g) .

Correct AnswerverifiedShow Answer

For the equilibrium (CH3) 3CCl(g) ⇆\leftrightarrows⇆ (CH3) 2C = CH2(g) + HCl(g) ,Kp = 3.45 at 500 K.At a given point,the partial pressures of the gases are = 0.810 atm and = 0.190 atm.Which of the following statements is true?

Correct AnswerverifiedShow Answer

An equilibrium that strongly favors products has __________

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Two students measure the equilibrium constant for the same chemical reaction.One student finds Kc to be 130; the other calculates Kc to be 11.4.The instructor checks their results and says they are both correct.Which of the following is a plausible explanation?

Correct AnswerverifiedShow Answer

An increase in the number of moles of gas as the reaction goes from reactants to products in a gas-phase equilibrium results in __________

Correct AnswerverifiedShow Answer

For the equilibrium 2 ClO(g) ⇆\leftrightarrows⇆ Cl2O2(g) ,Kc = 4.96 ×\times× 1011 at 253 K.What is Kc for the equilibrium Cl2O2(g) ⇆\leftrightarrows⇆ ClO(g) ?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A chemical equilibrium 2 A ⇆\leftrightarrows⇆ B has a forward rate constant,kf = 10 M -1 s-1,and a reverse rate constant,kr = 5 s-1.What is the value of the equilibrium constant for this system?

Correct AnswerverifiedShow Answer

Students often write expressions for the equilibrium constant Kc and reaction quotient Qc in exactly the same way.To avoid confusion,remember that Kc uses concentrations under __________ conditions while Qc uses concentrations under __________ conditions.

Correct AnswerverifiedShow Answer

Hydrofluoric acid,HF,dissociates in water according to the following reaction. HF(aq) ⇆\leftrightarrows⇆ H+(aq)+ F-(aq)Kc = 3.5 ×\times× 10-4 What is the concentration of H+ in a 0.0100 M solution of HF?

Correct AnswerverifiedUse the quadratic fo...View AnswerShow Answer

For the equilibrium NO2(g) + O2(g) ⇆\leftrightarrows⇆ NO(g) + O3(g) ,the equilibrium constant at 300.0 K is approximately 2.9 ×\times× 10-35,and the rate constant of the reverse reaction is approximately 8.5 ×\times× 106 M -1 s-1.What is the value of the forward rate constant?

Correct AnswerverifiedShow Answer

Addition of reactants to a chemical reaction in solution or gas phase at equilibrium results in __________

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Identify the equilibrium expression for the following reaction: CH₃CHO(g) $\leftrightarrows$ CH₄(g) + CO(g) .

Correct Answer
verified

Correct Answer
verified

Write the equilibrium expression for the following reaction: CH₄(g) + 2 H₂S(g) $\leftrightarrows$ CS₂(g) + 4 H₂(g) .

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Two students measure the equilibrium constant for the same chemical reaction.One student finds K_c to be 130; the other calculates K_c to be 11.4.The instructor checks their results and says they are both correct.Which of the following is a plausible explanation?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A chemical equilibrium 2A $\leftrightarrows$ B has a forward rate constant,k_f = 10 M ^-¹s^-¹,and a reverse rate constant,k_r = 5 s^-¹.What is the value of the equilibrium constant for this system?

Correct Answer
verified

Students often write expressions for the equilibrium constant K_c and reaction quotient Q_c in exactly the same way.To avoid confusion,remember that K_c uses concentrations under __________ conditions while Q_c uses concentrations under __________ conditions.

Correct Answer
verified

Hydrofluoric acid,HF,dissociates in water according to the following reaction. HF(aq) $\leftrightarrows$ H⁺(aq)+ F^-(aq)K_c = 3.5 $\times$ 10^-⁴ What is the concentration of H⁺ in a 0.0100 M solution of HF?

Correct Answer
verified
Use the quadratic fo...
View Answer

For the equilibrium NO₂(g) + O₂(g) $\leftrightarrows$ NO(g) + O₃(g) ,the equilibrium constant at 300.0 K is approximately 2.9 $\times$ 10^-35,and the rate constant of the reverse reaction is approximately 8.5 $\times$ 10⁶ M ^-¹s^-¹.What is the value of the forward rate constant?

Correct Answer
verified

Correct Answer
verified