Question 1

-From the graph above, which of the following is true when equilibrium has been reached?

Accepted Answer

A)  The concentrations of the reactants are larger than the concentration of the products. 
B)  The concentrations of the products are larger than the concentration of the reactants. 
C)  The concentrations of the reactants and products are equal. 
D)  This cannot be determined from the graph. 
A)  The concentrations of the reactants are larger than the concentration of the products. 
B)  The concentrations of the products are larger than the concentration of the reactants. 
C)  The concentrations of the reactants and products are equal. 
D)  This cannot be determined from the graph. A

Question 2

For the following reaction 2 NO2(g)   2 NO(g) + O2(g) &emsp; Kc = 7.4 x 10-16 (at 25°C)
If (NO2) = 0.10 M, (NO) = 0.010 M, and (O2) = 1.0 x 10-5 M, we can correctly predict

Accepted Answer

A)  that the reaction is at equilibrium. 
B)  that the reaction must shift to the left to reach equilibrium. 
C)  that the reaction must shift to the right to reach equilibrium. 
D)  nothing related to the question as to whether the reaction is at equilibrium. 
E)  nothing related to the question as to which direction the reaction has to shift to reach equilibrium. 
A)  that the reaction is at equilibrium. 
B)  that the reaction must shift to the left to reach equilibrium. 
C)  that the reaction must shift to the right to reach equilibrium. 
D)  nothing related to the question as to whether the reaction is at equilibrium. 
E)  nothing related to the question as to which direction the reaction has to shift to reach equilibrium. B

Question 3

What would be the effect of removing some NO2 from the following system after the reaction reaches equilibrium at 25°C?

2 NO2(g)   2 NO(g) + O2(g) &emsp; Kc = 7.4 x 10-16

Accepted Answer

A)  The NO and O2 concentrations would increase. 
B)  The NO and O2 concentrations would decrease. 
C)  The NO concentration would increase but O2 would decrease. 
D)  The O2 concentration would increase but NO would decrease. 
E)  The concentrations of NO and O2 would remain constant. 
A)  The NO and O2 concentrations would increase. 
B)  The NO and O2 concentrations would decrease. 
C)  The NO concentration would increase but O2 would decrease. 
D)  The O2 concentration would increase but NO would decrease. 
E)  The concentrations of NO and O2 would remain constant. B

Question 4

Calculate the NO, NO2, and O2 concentrations in the following gas-phase reaction at equilibrium at 200°C.

Accepted Answer

[NO] = 5.6

Question 5

For the following reaction:
2 NOCl(g)   2 NO(g) + Cl2(g) &emsp; &emsp; Kc = 5.6 x 10-6 (at 400 K)

If (NOCl) = 0.0222 M, (Cl2) = 0.0222 M, and (NO) = 0.989
 M at some moment in time, we can conclude that

Accepted Answer

A)  the reaction is at equilibrium. 
B)  some of the NOCl must be converted to NO and Cl2 to reach equilibrium. 
C)  some of the NO and Cl2 must be converted to NOCl to reach equilibrium. 
D)  it is impossible to determine which way the reaction must go to reach equilibrium. 
E)  the reaction can never reach equilibrium. 
A)  the reaction is at equilibrium. 
B)  some of the NOCl must be converted to NO and Cl2 to reach equilibrium. 
C)  some of the NO and Cl2 must be converted to NOCl to reach equilibrium. 
D)  it is impossible to determine which way the reaction must go to reach equilibrium. 
E)  the reaction can never reach equilibrium.

Question 6

What is the correct solubility constant expression for CaF2(s)?

Accepted Answer

A)    
B)  Ksp =  [Ca2+]2[  - ]  
C)  Ksp =  [Ca2+][ - ] 
D)  Ksp =  [Ca2+][F2]2 
E)  none of the above 
A)    
B)  Ksp =  [Ca2+]2[  - ]  
C)  Ksp =  [Ca2+][ - ] 
D)  Ksp =  [Ca2+][F2]2 
E)  none of the above

Question 7

What is the concentration in moles per liter of pure PbSO4(s) given that it has a density of 6.29 g/cm3?

Accepted Answer

A)  6.29 
B)  20.7  
C)  1.00 
D)  303 
E)  The concentration of a pure solid cannot be found. 
A)  6.29 
B)  20.7  
C)  1.00 
D)  303 
E)  The concentration of a pure solid cannot be found.

Question 8

-What happens with respect to time to the products of this reaction in the kinetic region of the graph above?

Accepted Answer

A)  the products increase 
B)  the products decrease 
C)  the products remain constant 
D)  cannot be determined from the graph 
A)  the products increase 
B)  the products decrease 
C)  the products remain constant 
D)  cannot be determined from the graph

Question 9

Calculate the concentrations of Cl2 and ClF3 at equilibrium if a reaction that initially contained 1.000 M concentrations of both Cl2 and F2 is found to have an F2 concentration of 0.700 M at equilibrium.

Accepted Answer

A)  [Cl2] = 0.700M [ClF3] = 0.700M 
B)  [Cl2] = 0.700M [ClF3] = 0.300M 
C)  [Cl2] = 0.500M [ClF3] = 0.300M 
D)  [Cl2] = 0.900M [ClF3] = 0.200M 
E)  none of these 
A)  [Cl2] = 0.700M [ClF3] = 0.700M 
B)  [Cl2] = 0.700M [ClF3] = 0.300M 
C)  [Cl2] = 0.500M [ClF3] = 0.300M 
D)  [Cl2] = 0.900M [ClF3] = 0.200M 
E)  none of these

Question 10

In which of the following will the least PbBr2(s) dissolve?

Accepted Answer

A)  pure water 
B)  0.01 M NaBr 
C)  0.01 M KBr 
D)  0.02 M NaBr 
E)  PbBr2(s) will be equally soluble in all of the above solutions. 
A)  pure water 
B)  0.01 M NaBr 
C)  0.01 M KBr 
D)  0.02 M NaBr 
E)  PbBr2(s) will be equally soluble in all of the above solutions.

Question 11

If the equilibrium constant for the following reaction is Kc = 1 x 102
2 C2H6(g) + 7 O2(g)   4 CO2(g) + 6 H2O(g)
And all the concentrations were initially 0.10 M, we can predict that the reaction

Accepted Answer

A)  is at equilibrium initially. 
B)  must shift from left to right to reach equilibrium. 
C)  must shift from right to left to reach equilibrium. 
D)  cannot reach equilibrium. 
E)  cannot be determined unless we have the information necessary to calculate Qc for the reaction. 
A)  is at equilibrium initially. 
B)  must shift from left to right to reach equilibrium. 
C)  must shift from right to left to reach equilibrium. 
D)  cannot reach equilibrium. 
E)  cannot be determined unless we have the information necessary to calculate Qc for the reaction.

Question 12

Under which set of conditions must the following reaction always proceed to the right in order to reach equilibrium?

H2(g) + I2(g)   2 HI(g)

Accepted Answer

A)  Qc c > 1 
C)  Qc = 1 
D)  Qc > Kc 
E)  none of these 
A)  Qc c > 1 
C)  Qc = 1 
D)  Qc > Kc 
E)  none of these

Question 13

Which is the correct equilibrium constant expression for the reaction:

2 SO2(g) + O2(g)   2 SO3(g)

Accepted Answer

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

Question 14

Hidden Assumptions that make Equilibrium Calculations Easier What Do We Do When the Approximation Fails?
 based on the following reaction:

2HS1U1B12S1U1B0O(g)   2HS1U1B12S1U1B0(g) + OS1U1B12S1U1B0(g)
KS1U1B1cS1U1B0 = 2 x 10S1U1P1-42S1S1P0 (at 25S1U1P1oS1S1P0C)
-Starting with 0.10 M H2O(g), what would be the best strategy for solving for the equilibrium concentrations of H2O, H2 and O2?

Accepted Answer

A)  Since the change in the concentrations are expected to be large going to equilibrium, the equation will have to be solved exactly. 
B)  Since the changes in the concentrations are expected to be large going to equilibrium, it is best to assume that all of the H2O(g) is converted to products and then calculate the equilibrium concentration. 
C)  Since the changes in concentrations are expected to be small going to equilibrium, it is best to assume that the changes will be small relative to the initial concentration of H2O(g). 
D)  Since the changes in concentrations are expected to be small going to equilibrium, it is best to assume that the changes will be large relative to the initial concentration of H2O(g). 
E)  There is no reasonable way to even approximate the answer to this problem. 
A)  Since the change in the concentrations are expected to be large going to equilibrium, the equation will have to be solved exactly. 
B)  Since the changes in the concentrations are expected to be large going to equilibrium, it is best to assume that all of the H2O(g) is converted to products and then calculate the equilibrium concentration. 
C)  Since the changes in concentrations are expected to be small going to equilibrium, it is best to assume that the changes will be small relative to the initial concentration of H2O(g). 
D)  Since the changes in concentrations are expected to be small going to equilibrium, it is best to assume that the changes will be large relative to the initial concentration of H2O(g). 
E)  There is no reasonable way to even approximate the answer to this problem.

Question 15

Calculate the COCl2, CO, and Cl2 concentrations when the following gas-phase reaction reaches equilibrium at 300°C.

Accepted Answer

[CO] = 1 x

Question 16

Which of the following factors will cause this chemical reaction to shift its equilibrium to the right?

Xe(g) + 2 F2(g)   XeF4(g) &emsp;  $\Delta$ H = -218 kJ/molrxn

Accepted Answer

A)  increasing the temperature 
B)  increasing the pressure 
C)  decreasing the pressure 
D)  increasing the concentration of XeF4 
E)  decreasing the concentration of F2 
A)  increasing the temperature 
B)  increasing the pressure 
C)  decreasing the pressure 
D)  increasing the concentration of XeF4 
E)  decreasing the concentration of F2

Question 17

For the following reaction:
2 NOCl(g)   2 NO2(g) + Cl2(g) &emsp; Kc = 5.6 x 10-6  (at 400 K)
If (NOCl) = 0.0222 M, (Cl2) = 0.0222 M, and (NO2) = 0.989 M at some moment in time, which of the following would be true?

Accepted Answer

A)  The rate of the forward reaction would be exactly equal to the rate of the reverse reaction. 
B)  Neither the forward nor the reverse reaction would occur because the reaction would be at equilibrium. 
C)  The rate of the forward reaction would be faster than the reverse reaction. 
D)  The rate of the reverse reaction would be faster than the forward reaction. 
E)  There is no relationship between these concentrations and the rate of either the forward or the reverse reaction. 
A)  The rate of the forward reaction would be exactly equal to the rate of the reverse reaction. 
B)  Neither the forward nor the reverse reaction would occur because the reaction would be at equilibrium. 
C)  The rate of the forward reaction would be faster than the reverse reaction. 
D)  The rate of the reverse reaction would be faster than the forward reaction. 
E)  There is no relationship between these concentrations and the rate of either the forward or the reverse reaction.

Question 18

Based on the information given in the previous problem, the equilibrium constant for the following reaction would be:

2IBr(g)   I2(g) + Br2(g)

Accepted Answer

A)  -1.1 x 102 
B)  9.1 x 10-3 
C)  10.5 
D)  1.1 x 10-2 
E)  none of the above 
A)  -1.1 x 102 
B)  9.1 x 10-3 
C)  10.5 
D)  1.1 x 10-2 
E)  none of the above

Question 19

Which of the following graphs best represents the relationship between the concentration of reactants and products with respect to time for the following chemical reaction?

2 H2(g) + O2(g)   2 H2O(g)

Accepted Answer

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

Question 20

Assume that the equilibrium constant for the following reaction is known.

2 NO2(g)   2 NO(g) + O2(g) &emsp; K1 = 7.4 x 10-16 (at 25°C)

What is the correct value of the equilibrium constant for the opposite reaction?
2 NO(g) + O2(g)   2 NO2(g) &emsp; K2 = ?

Accepted Answer

A)  K2 = K1 = 7.4 x 10-16 
B)  K2 = 1/K1 = 1.4 x 1015 
C)  K2 = K1(RT) = 1.8 x 10-14 
D)  K2 = K1(RT)-1 = 3.0 x 10-17 
E)  impossible to determine from this information 
A)  K2 = K1 = 7.4 x 10-16 
B)  K2 = 1/K1 = 1.4 x 1015 
C)  K2 = K1(RT) = 1.8 x 10-14 
D)  K2 = K1(RT)-1 = 3.0 x 10-17 
E)  impossible to determine from this information

-From the graph above, which of the following is true when equilibrium has been reached?

For the following reaction 2 NO₂(g) 2 NO(g) + O₂(g) K_c = 7.4 x 10^-16 (at 25°C) If (NO₂) = 0.10 M, (NO) = 0.010 M, and (O₂) = 1.0 x 10^-5 M, we can correctly predict

What would be the effect of removing some NO₂ from the following system after the reaction reaches equilibrium at 25°C? 2 NO₂(g) 2 NO(g) + O₂(g) K_c = 7.4 x 10^-16

Calculate the NO, NO₂, and O₂ concentrations in the following gas-phase reaction at equilibrium at 200°C.

For the following reaction: 2 NOCl(g) 2 NO(g) + Cl₂(g) K_c = 5.6 x 10^-6 (at 400 K) If (NOCl) = 0.0222 M, (Cl₂) = 0.0222 M, and (NO) = 0.989 M at some moment in time, we can conclude that

What is the correct solubility constant expression for CaF₂(s)?

What is the concentration in moles per liter of pure PbSO₄(s) given that it has a density of 6.29 g/cm³?

-What happens with respect to time to the products of this reaction in the kinetic region of the graph above?

Calculate the concentrations of Cl₂ and ClF₃ at equilibrium if a reaction that initially contained 1.000 M concentrations of both Cl₂ and F₂is found to have an F₂ concentration of 0.700 M at equilibrium.

In which of the following will the least PbBr₂(s) dissolve?

If the equilibrium constant for the following reaction is K_c = 1 x 10² 2 C₂H₆(g) + 7 O₂(g) 4 CO₂(g) + 6 H₂O(g) And all the concentrations were initially 0.10 M, we can predict that the reaction

Under which set of conditions must the following reaction always proceed to the right in order to reach equilibrium? H₂(g) + I₂(g) 2 HI(g)

Which is the correct equilibrium constant expression for the reaction: 2 SO_2(g) + O_2(g) 2 SO_3(g)

Calculate the COCl₂, CO, and Cl₂ concentrations when the following gas-phase reaction reaches equilibrium at 300°C.

For the following reaction: 2 NOCl(g) 2 NO₂(g) + Cl₂(g) K_c = 5.6 x 10^-6 (at 400 K) If (NOCl) = 0.0222 M, (Cl₂) = 0.0222 M, and (NO₂) = 0.989 M at some moment in time, which of the following would be true?

Based on the information given in the previous problem, the equilibrium constant for the following reaction would be: 2IBr(g) I₂(g) + Br₂(g)

Which of the following graphs best represents the relationship between the concentration of reactants and products with respect to time for the following chemical reaction? 2 H₂(g) + O₂(g) 2 H₂O(g)

Assume that the equilibrium constant for the following reaction is known. 2 NO₂(g) 2 NO(g) + O₂(g) K₁ = 7.4 x 10^-16 (at 25°C) What is the correct value of the equilibrium constant for the opposite reaction? 2 NO(g) + O₂(g) 2 NO₂(g) K₂ = ?

Elements Compounds

The Mole

Structure of the Atom

The Covalent Bond

Ionic and Metallic Bonds

Gases

Making and Breaking of Bonds

Liquids and Solutions

Solids

Acids and Bases

Oxidation-Reduction Reactions

Chemical Thermodynamics

Kinetics

Nuclear Chemistry

Organic Chemistry

Filters

Exam 10: An Introduction to Kinetics and Equilibrium

-From the graph above, which of the following is true when equilibrium has been reached?

For the following reaction 2 NO2(g) 2 NO(g) + O2(g) Kc = 7.4 x 10-16 (at 25°C) If (NO2) = 0.10 M, (NO) = 0.010 M, and (O2) = 1.0 x 10-5 M, we can correctly predict

What would be the effect of removing some NO2 from the following system after the reaction reaches equilibrium at 25°C? 2 NO2(g) 2 NO(g) + O2(g) Kc = 7.4 x 10-16

Calculate the NO, NO2, and O2 concentrations in the following gas-phase reaction at equilibrium at 200°C.

For the following reaction: 2 NOCl(g) 2 NO(g) + Cl2(g) Kc = 5.6 x 10-6 (at 400 K) If (NOCl) = 0.0222 M, (Cl2) = 0.0222 M, and (NO) = 0.989 M at some moment in time, we can conclude that

What is the correct solubility constant expression for CaF2(s)?

What is the concentration in moles per liter of pure PbSO4(s) given that it has a density of 6.29 g/cm3?

-What happens with respect to time to the products of this reaction in the kinetic region of the graph above?

Calculate the concentrations of Cl2 and ClF3 at equilibrium if a reaction that initially contained 1.000 M concentrations of both Cl2 and F2 is found to have an F2 concentration of 0.700 M at equilibrium.

In which of the following will the least PbBr2(s) dissolve?

If the equilibrium constant for the following reaction is Kc = 1 x 102 2 C2H6(g) + 7 O2(g) 4 CO2(g) + 6 H2O(g) And all the concentrations were initially 0.10 M, we can predict that the reaction

Under which set of conditions must the following reaction always proceed to the right in order to reach equilibrium? H2(g) + I2(g) 2 HI(g)

Which is the correct equilibrium constant expression for the reaction: 2 SO2(g) + O2(g) 2 SO3(g)

Calculate the COCl2, CO, and Cl2 concentrations when the following gas-phase reaction reaches equilibrium at 300°C.

Which of the following factors will cause this chemical reaction to shift its equilibrium to the right? Xe(g) + 2 F2(g) XeF4(g) Δ\DeltaΔ H = -218 kJ/molrxn

For the following reaction: 2 NOCl(g) 2 NO2(g) + Cl2(g) Kc = 5.6 x 10-6 (at 400 K) If (NOCl) = 0.0222 M, (Cl2) = 0.0222 M, and (NO2) = 0.989 M at some moment in time, which of the following would be true?

Based on the information given in the previous problem, the equilibrium constant for the following reaction would be: 2IBr(g) I2(g) + Br2(g)

Which of the following graphs best represents the relationship between the concentration of reactants and products with respect to time for the following chemical reaction? 2 H2(g) + O2(g) 2 H2O(g)

Assume that the equilibrium constant for the following reaction is known. 2 NO2(g) 2 NO(g) + O2(g) K1 = 7.4 x 10-16 (at 25°C) What is the correct value of the equilibrium constant for the opposite reaction? 2 NO(g) + O2(g) 2 NO2(g) K2 = ?

Elements Compounds

The Mole

Structure of the Atom

The Covalent Bond

Ionic and Metallic Bonds

Gases

Making and Breaking of Bonds

Liquids and Solutions

Solids

Acids and Bases

Oxidation-Reduction Reactions

Chemical Thermodynamics

Kinetics

Nuclear Chemistry

Organic Chemistry

Filters

For the following reaction 2 NO₂(g) 2 NO(g) + O₂(g) K_c = 7.4 x 10^-16 (at 25°C) If (NO₂) = 0.10 M, (NO) = 0.010 M, and (O₂) = 1.0 x 10^-5 M, we can correctly predict

What would be the effect of removing some NO₂ from the following system after the reaction reaches equilibrium at 25°C? 2 NO₂(g) 2 NO(g) + O₂(g) K_c = 7.4 x 10^-16

Calculate the NO, NO₂, and O₂ concentrations in the following gas-phase reaction at equilibrium at 200°C.

For the following reaction: 2 NOCl(g) 2 NO(g) + Cl₂(g) K_c = 5.6 x 10^-6 (at 400 K) If (NOCl) = 0.0222 M, (Cl₂) = 0.0222 M, and (NO) = 0.989 M at some moment in time, we can conclude that

What is the correct solubility constant expression for CaF₂(s)?

What is the concentration in moles per liter of pure PbSO₄(s) given that it has a density of 6.29 g/cm³?

Calculate the concentrations of Cl₂ and ClF₃ at equilibrium if a reaction that initially contained 1.000 M concentrations of both Cl₂ and F₂is found to have an F₂ concentration of 0.700 M at equilibrium.

In which of the following will the least PbBr₂(s) dissolve?

If the equilibrium constant for the following reaction is K_c = 1 x 10² 2 C₂H₆(g) + 7 O₂(g) 4 CO₂(g) + 6 H₂O(g) And all the concentrations were initially 0.10 M, we can predict that the reaction

Under which set of conditions must the following reaction always proceed to the right in order to reach equilibrium? H₂(g) + I₂(g) 2 HI(g)

Which is the correct equilibrium constant expression for the reaction: 2 SO_2(g) + O_2(g) 2 SO_3(g)

Calculate the COCl₂, CO, and Cl₂ concentrations when the following gas-phase reaction reaches equilibrium at 300°C.

For the following reaction: 2 NOCl(g) 2 NO₂(g) + Cl₂(g) K_c = 5.6 x 10^-6 (at 400 K) If (NOCl) = 0.0222 M, (Cl₂) = 0.0222 M, and (NO₂) = 0.989 M at some moment in time, which of the following would be true?

Based on the information given in the previous problem, the equilibrium constant for the following reaction would be: 2IBr(g) I₂(g) + Br₂(g)

Which of the following graphs best represents the relationship between the concentration of reactants and products with respect to time for the following chemical reaction? 2 H₂(g) + O₂(g) 2 H₂O(g)

Assume that the equilibrium constant for the following reaction is known. 2 NO₂(g) 2 NO(g) + O₂(g) K₁ = 7.4 x 10^-16 (at 25°C) What is the correct value of the equilibrium constant for the opposite reaction? 2 NO(g) + O₂(g) 2 NO₂(g) K₂ = ?