Question 1

For the reaction 2NO(g)+ O2 
   
2NO2(g)at 750°C,what is the relationship between Kc and Kp?

Accepted Answer

A) Kc = Kp 
B) Kc = Kp × (RT)-1 
C) Kc = Kp = 1.0 
D) Kc = Kp × (RT)3/4 
E) Kc = Kp × (RT)1 
A) Kc = Kp 
B) Kc = Kp × (RT)-1 
C) Kc = Kp = 1.0 
D) Kc = Kp × (RT)3/4 
E) Kc = Kp × (RT)1

Question 2

Which of the following,when added to an equilibrium mixture represented by the equlibrium below,will not alter the composition of the original equilibrium mixture?
Mg(OH)2(s)  
Mg2+(aq)+ 2OH-(aq)

Accepted Answer

A) Addition of Mg(NO3)2(s)to the equilibrium mixture. 
B) Addition of Fe(NO3)3(aq)from the equilibrium mixture. 
C) Addition of Mg(OH)2(s)to the equilibrium mixture. 
D) Addition of HCl(aq)to the equilibrium mixture. 
E) Addition of NaOH(s)to the equilibrium mixture. 
A) Addition of Mg(NO3)2(s)to the equilibrium mixture. 
B) Addition of Fe(NO3)3(aq)from the equilibrium mixture. 
C) Addition of Mg(OH)2(s)to the equilibrium mixture. 
D) Addition of HCl(aq)to the equilibrium mixture. 
E) Addition of NaOH(s)to the equilibrium mixture.

Question 3

Consider the following equilibrium.
4NH3(g)+ 3O2(g)  
2N2(g)+ 6H2O(g)
Suppose 0.30 mol of NH3 and 0.40 mol of oxygen are added to a 5.0-L container.If x mol of water is present at equilibrium,what is the equilibrium concentration of oxygen?

Accepted Answer

A) 0.40 - 0.50x 
B) 0.30 - 0.50x 
C) 0.08 - 0.10x 
D) 0.06 - 0.13x 
E) 0.40 -   x 
A) 0.40 - 0.50x 
B) 0.30 - 0.50x 
C) 0.08 - 0.10x 
D) 0.06 - 0.13x 
E) 0.40 -   x

Question 4

Consider the reaction represented by the equation N2(g)+ 3H2(g)   2NH3(g).What happens to the equilibrium position when an inert gas is added to this system (as represented above)at equilibrium?

Accepted Answer

A) If the container is rigid,the equilibrium position shifts.If the container is fitted with a movable piston,nothing happens to the equilibrium position. 
B) If the container is rigid,nothing happens to the equilibrium position.If the container is fitted with a movable piston,the equilibrium position shifts. 
C) Nothing happens to the equilibrium position no matter what the container is like. 
D) The equilibrium position shifts no matter what the container is like. 
E) The value of the equilibrium constant must be known to answer this question. 
A) If the container is rigid,the equilibrium position shifts.If the container is fitted with a movable piston,nothing happens to the equilibrium position. 
B) If the container is rigid,nothing happens to the equilibrium position.If the container is fitted with a movable piston,the equilibrium position shifts. 
C) Nothing happens to the equilibrium position no matter what the container is like. 
D) The equilibrium position shifts no matter what the container is like. 
E) The value of the equilibrium constant must be known to answer this question.

Question 5

CS2(g)+ 3Cl2(g)   CCl4(g)+ S2Cl2(g)
At a given temperature,the reaction above is at equilibrium when [CS2] = 0.050 M,[Cl2] = 0.25 M,[CCl4] = 0.15 M,and [S2Cl2] = 0.35 M.What will be the direction of the reaction when the reactants and products have the following concentrations: CS2 = 0.14 M,Cl2 = 0.20 M,CCl4 = 0.28 M,and S2Cl2 = 0.28 M?

Accepted Answer

A) to the left 
B) to the right 
C) no change 
D) cannot predict unless we know the temperature 
E) cannot predict unless we know whether the reaction is endothermic or exothermic 
A) to the left 
B) to the right 
C) no change 
D) cannot predict unless we know the temperature 
E) cannot predict unless we know whether the reaction is endothermic or exothermic

Question 6

For the endothermic reaction 2CO2(g)+ N2(g)   2NO(g)+ 2CO(g),the conditions that favor maximum conversion of the reactants to products are

Accepted Answer

A) high temperature and low pressure. 
B) high temperature,pressure being unimportant. 
C) low temperature and low pressure. 
D) low temperature and high pressure. 
E) high temperature and high pressure. 
A) high temperature and low pressure. 
B) high temperature,pressure being unimportant. 
C) low temperature and low pressure. 
D) low temperature and high pressure. 
E) high temperature and high pressure.

Question 7

What is the Kc equilibrium-constant expression for the following equilibrium?
S8(s)+ 24F2(g)  
8SF6(g)

Accepted Answer

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

Question 8

Which of the following is true for a system whose equilibrium constant is much smaller than one?

Accepted Answer

A) The reaction mixture contains mostly reactants at equilibrium. 
B) The reaction mixture contains mostly products at equilibrium. 
C) The rate of reaction is very slow. 
D) The moles of reactants and products are relatively similar at equilibrium. 
E) Both A and C. 
A) The reaction mixture contains mostly reactants at equilibrium. 
B) The reaction mixture contains mostly products at equilibrium. 
C) The rate of reaction is very slow. 
D) The moles of reactants and products are relatively similar at equilibrium. 
E) Both A and C.

Question 9

For a specific reaction,which of the following statements can be made about the equilibrium constant?

Accepted Answer

A) It can be changed by the addition of a catalyst. 
B) It increases when the concentration of one of the products is increased. 
C) It increases when the concentration of one of the reactants is increased. 
D) It always remains the same. 
E) It changes with changes in the temperature. 
A) It can be changed by the addition of a catalyst. 
B) It increases when the concentration of one of the products is increased. 
C) It increases when the concentration of one of the reactants is increased. 
D) It always remains the same. 
E) It changes with changes in the temperature.

Question 10

For the reaction 2H2S(g)   2H2(g)+ S2(g),Kc = 9.1 × 102 at 750 K.What will happen when 0.10 mol of H2S,1.0 mol of H2,and 1.5 mol of S2 are added to a 1.0-L container and the system is brought to 750 K?

Accepted Answer

A) More S2 will be formed than H2. 
B) More H2 will be formed than S2. 
C) Nothing; the system is at equilibrium. 
D) The amount of H2 formed will be half the amount of S2 formed. 
E) More H2S will be formed. 
A) More S2 will be formed than H2. 
B) More H2 will be formed than S2. 
C) Nothing; the system is at equilibrium. 
D) The amount of H2 formed will be half the amount of S2 formed. 
E) More H2S will be formed.

Question 11

At 400 K,an equilibrium mixture of H2,I2,and HI consists of 0.025 mol H2,0.067 mol I2,and 0 mol HI in a 3.50-L flask.What is the value of Kp for the following equilibrium? (R = 0.0821 L ∙ atm/(K ∙ mol))
2HI(g)  H2(g)+ I2(g)

Accepted Answer

A) 0 
B) 15 
C) 2 
D) 45 
E) 3 
A) 0 
B) 15 
C) 2 
D) 45 
E) 3

Question 12

Given the equilibrium constants for the equilibria,
22NH4+(aq)+ 2H2O(l)  
2NH3(aq)+ 2H3O+(aq); Kc =  
CH3COOH(aq)+ H2O(l)  
CH3COO-(aq)+ H3O+(aq); Kc =  
Determine Kc for the following equilibrium.
CH3COOH(aq)+ NH3(aq)  
CH3COO-(aq)+ NH4+(aq)

Accepted Answer

A) 3.08 × 104 
B) 3.25 × 10-5 
C) 9.96 × 10-15 
D) 1.00 × 1014 
E) 1.75 × 10-5 
A) 3.08 × 104 
B) 3.25 × 10-5 
C) 9.96 × 10-15 
D) 1.00 × 1014 
E) 1.75 × 10-5

Question 13

What is the Kp equilibrium-constant expression for the following equilibrium?
Ti(s)+ 2Cl2(g)  
TiCl4(l)

Accepted Answer

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

Question 14

Consider the following equilibrium:
4NH3(g)+ 3O2(g)  
2N2(g)+ 6H2O(g)
Suppose 0.30 mol of NH3 and 0.40 mol of oxygen are added to a 5.0-L container.If x mol of water is present at equilibrium,how many moles of ammonia will remain at equilibrium?

Accepted Answer

A) 0.30 -   x 
B) 0.30 - x 
C) 0.30 -   x 
D) 0.40 -   x 
E)    x 
A) 0.30 -   x 
B) 0.30 - x 
C) 0.30 -   x 
D) 0.40 -   x 
E)    x

Question 15

The reaction of a mixture of SO2 and O2 at a given temperature is represented by the equation
2SO2(g)+ O2(g)  
2SO3(g)
When equilibrium is established,which of the following ratios is constant regardless of the initial concentrations of SO2 and O2?

Accepted Answer

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

Question 16

What is the Kp equilibrium-constant expression for the following equilibrium?
S8(s)+ 24F2(g)  
8SF6(g)

Accepted Answer

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

Question 17

Which of the following is always true for a reaction where Kc is   at 25°C?

Accepted Answer

A) The reaction mixture contains mostly products at equilibrium. 
B) The reaction mixture contains mostly reactants at equilibrium. 
C) The rate of reaction is very fast. 
D) There are approximately equal moles of reactants and products at equilibrium. 
E) Both A and C. 
A) The reaction mixture contains mostly products at equilibrium. 
B) The reaction mixture contains mostly reactants at equilibrium. 
C) The rate of reaction is very fast. 
D) There are approximately equal moles of reactants and products at equilibrium. 
E) Both A and C.

Question 18

Consider the following equilibrium:
CO2(g)+ H2(g)  
CO(g)+ H2O(g); Kc = 1.6 at 1260 K
Suppose 0.037 mol CO2 and 0.020 mol H2 are placed in a 3.50-L vessel at 1260 K.What is the equilibrium partial pressure of CO(g)? (R = 0.0821 L ∙ atm/(K ∙ mol))

Accepted Answer

A) 4.1 atm 
B) 0.5 atm 
C) 1.6 atm 
D) 1.1 atm 
E) 0.59 atm 
A) 4.1 atm 
B) 0.5 atm 
C) 1.6 atm 
D) 1.1 atm 
E) 0.59 atm

Question 19

What is the Kc equilibrium-constant expression for the following equilibrium?
SrO(s)+ H2(g)  
Sr(s)+ H2O(g)

Accepted Answer

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

Question 20

For the equilibrium PCl5(g)   PCl3(g)+ Cl2(g),Kc = 4.0 at 228°C.If pure PCl5 is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl5(g)is 0.26 M,what is the equilibrium concentration of PCl3?

Accepted Answer

A) 0.11 M 
B) 0.38 M 
C) 0.23 M 
D) 0.95 M 
E) 0.013 M 
A) 0.11 M 
B) 0.38 M 
C) 0.23 M 
D) 0.95 M 
E) 0.013 M

Exam 14: Chemical Equilibrium

For the reaction 2NO(g)+ O2 2NO2(g)at 750°C,what is the relationship between Kc and Kp?

Which of the following,when added to an equilibrium mixture represented by the equlibrium below,will not alter the composition of the original equilibrium mixture? Mg(OH)2(s) Mg2+(aq)+ 2OH-(aq)

Consider the following equilibrium. 4NH3(g)+ 3O2(g) 2N2(g)+ 6H2O(g) Suppose 0.30 mol of NH3 and 0.40 mol of oxygen are added to a 5.0-L container.If x mol of water is present at equilibrium,what is the equilibrium concentration of oxygen?

Consider the reaction represented by the equation N2(g)+ 3H2(g) 2NH3(g).What happens to the equilibrium position when an inert gas is added to this system (as represented above)at equilibrium?

For the endothermic reaction 2CO2(g)+ N2(g) 2NO(g)+ 2CO(g),the conditions that favor maximum conversion of the reactants to products are

What is the Kc equilibrium-constant expression for the following equilibrium? S8(s)+ 24F2(g) 8SF6(g)

Which of the following is true for a system whose equilibrium constant is much smaller than one?

For a specific reaction,which of the following statements can be made about the equilibrium constant?

For the reaction 2H2S(g) 2H2(g)+ S2(g),Kc = 9.1 × 102 at 750 K.What will happen when 0.10 mol of H2S,1.0 mol of H2,and 1.5 mol of S2 are added to a 1.0-L container and the system is brought to 750 K?

At 400 K,an equilibrium mixture of H2,I2,and HI consists of 0.025 mol H2,0.067 mol I2,and 0 mol HI in a 3.50-L flask.What is the value of Kp for the following equilibrium? (R = 0.0821 L ∙ atm/(K ∙ mol)) 2HI(g) H2(g)+ I2(g)

Given the equilibrium constants for the equilibria, 22NH4+(aq)+ 2H2O(l) 2NH3(aq)+ 2H3O+(aq); Kc = CH3COOH(aq)+ H2O(l) CH3COO-(aq)+ H3O+(aq); Kc = Determine Kc for the following equilibrium. CH3COOH(aq)+ NH3(aq) CH3COO-(aq)+ NH4+(aq)

What is the Kp equilibrium-constant expression for the following equilibrium? Ti(s)+ 2Cl2(g) TiCl4(l)

Consider the following equilibrium: 4NH3(g)+ 3O2(g) 2N2(g)+ 6H2O(g) Suppose 0.30 mol of NH3 and 0.40 mol of oxygen are added to a 5.0-L container.If x mol of water is present at equilibrium,how many moles of ammonia will remain at equilibrium?

The reaction of a mixture of SO2 and O2 at a given temperature is represented by the equation 2SO2(g)+ O2(g) 2SO3(g) When equilibrium is established,which of the following ratios is constant regardless of the initial concentrations of SO2 and O2?

What is the Kp equilibrium-constant expression for the following equilibrium? S8(s)+ 24F2(g) 8SF6(g)

Which of the following is always true for a reaction where Kc is at 25°C?

Consider the following equilibrium: CO2(g)+ H2(g) CO(g)+ H2O(g); Kc = 1.6 at 1260 K Suppose 0.037 mol CO2 and 0.020 mol H2 are placed in a 3.50-L vessel at 1260 K.What is the equilibrium partial pressure of CO(g)? (R = 0.0821 L ∙ atm/(K ∙ mol))

What is the Kc equilibrium-constant expression for the following equilibrium? SrO(s)+ H2(g) Sr(s)+ H2O(g)

For the equilibrium PCl5(g) PCl3(g)+ Cl2(g),Kc = 4.0 at 228°C.If pure PCl5 is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl5(g)is 0.26 M,what is the equilibrium concentration of PCl3?

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For the reaction 2NO(g)+ O₂ 2NO₂(g)at 750°C,what is the relationship between K_c and K_p?

Which of the following,when added to an equilibrium mixture represented by the equlibrium below,will not alter the composition of the original equilibrium mixture? Mg(OH)₂(s) Mg²⁺(aq)+ 2OH^-(aq)

Consider the following equilibrium. 4NH₃(g)+ 3O₂(g) 2N₂(g)+ 6H₂O(g) Suppose 0.30 mol of NH₃ and 0.40 mol of oxygen are added to a 5.0-L container.If x mol of water is present at equilibrium,what is the equilibrium concentration of oxygen?

Consider the reaction represented by the equation N₂(g)+ 3H₂(g) 2NH₃(g).What happens to the equilibrium position when an inert gas is added to this system (as represented above)at equilibrium?

For the endothermic reaction 2CO₂(g)+ N₂(g) 2NO(g)+ 2CO(g),the conditions that favor maximum conversion of the reactants to products are

What is the K_c equilibrium-constant expression for the following equilibrium? S₈(s)+ 24F₂(g) 8SF₆(g)

For the reaction 2H₂S(g) 2H₂(g)+ S₂(g),K_c = 9.1 × 10² at 750 K.What will happen when 0.10 mol of H₂S,1.0 mol of H₂,and 1.5 mol of S₂ are added to a 1.0-L container and the system is brought to 750 K?

At 400 K,an equilibrium mixture of H₂,I₂,and HI consists of 0.025 mol H₂,0.067 mol I₂,and 0 mol HI in a 3.50-L flask.What is the value of K_p for the following equilibrium? (R = 0.0821 L ∙ atm/(K ∙ mol)) 2HI(g) H₂(g)+ I₂(g)

Given the equilibrium constants for the equilibria, 22NH₄⁺(aq)+ 2H₂O(l) 2NH₃(aq)+ 2H₃O⁺(aq); K_c = CH₃COOH(aq)+ H₂O(l) CH₃COO^-(aq)+ H₃O⁺(aq); K_c = Determine K_c for the following equilibrium. CH₃COOH(aq)+ NH₃(aq) CH₃COO^-(aq)+ NH₄⁺(aq)

What is the K_p equilibrium-constant expression for the following equilibrium? Ti(s)+ 2Cl₂(g) TiCl₄(l)

Consider the following equilibrium: 4NH₃(g)+ 3O₂(g) 2N₂(g)+ 6H₂O(g) Suppose 0.30 mol of NH₃ and 0.40 mol of oxygen are added to a 5.0-L container.If x mol of water is present at equilibrium,how many moles of ammonia will remain at equilibrium?

The reaction of a mixture of SO₂ and O₂ at a given temperature is represented by the equation 2SO₂(g)+ O₂(g) 2SO₃(g) When equilibrium is established,which of the following ratios is constant regardless of the initial concentrations of SO₂ and O₂?

What is the K_p equilibrium-constant expression for the following equilibrium? S₈(s)+ 24F₂(g) 8SF₆(g)

Which of the following is always true for a reaction where K_c is at 25°C?

Consider the following equilibrium: CO₂(g)+ H₂(g) CO(g)+ H₂O(g); K_c = 1.6 at 1260 K Suppose 0.037 mol CO₂ and 0.020 mol H₂ are placed in a 3.50-L vessel at 1260 K.What is the equilibrium partial pressure of CO(g)? (R = 0.0821 L ∙ atm/(K ∙ mol))

What is the K_c equilibrium-constant expression for the following equilibrium? SrO(s)+ H₂(g) Sr(s)+ H₂O(g)

For the equilibrium PCl₅(g) PCl₃(g)+ Cl₂(g),K_c = 4.0 at 228°C.If pure PCl₅ is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl₅(g)is 0.26 M,what is the equilibrium concentration of PCl₃?