Question 1

What is the relationship between Kp and Kc for the reaction below?
4 NH3(g)+ 7 O2(g)⇌ 2 N2O4(g)+ 6 H2O(g)

Accepted Answer

A) Kp = Kc(RT)-3 
B) Kc = Kp(RT)-3 
C) Kp = Kc(RT)3 
D) Kp = Kc(RT) 
E) Kp = Kc 
A) Kp = Kc(RT)-3 
B) Kc = Kp(RT)-3 
C) Kp = Kc(RT)3 
D) Kp = Kc(RT) 
E) Kp = Kc

Question 2

Write the equilibrium constant expression for the following reaction:
6 CO2(g)+ 6 H2O(l)⇌ C6H12O6(s)+ 6 O2(g)

Accepted Answer

A) Kc =   
B) Kc =   
C) Kc =   
D) Kc =   
E) Kc =   
A) Kc =   
B) Kc =   
C) Kc =   
D) Kc =   
E) Kc =

Question 3

Consider the equilibrium system: N2O4(g)⇌ 2 NO2(g)for which Kp = 0.1134 at 25 °C and ΔrH° = 58.03 kJ/mol.Assume that 1 mole of N2O4 and 2 moles of NO2 are introduced into a 5.0 liter container.What will be the equilibrium value of [N2O4]?

Accepted Answer

A) 0.928 M 
B) 0.0822 M 
C) 0.358 M 
D) 0.379 M 
E) 0.042 M 
A) 0.928 M 
B) 0.0822 M 
C) 0.358 M 
D) 0.379 M 
E) 0.042 M

Question 4

In a reaction at equilibrium involving only gases,a pressure change will shift the reaction only when:

Accepted Answer

A) heat is absorbed by the reaction proceeding to the right 
B) the number of molecules on one side is greater than the number on the other side of the balanced equation 
C) the number of molecules increases during the chemical reaction 
D) the gases are impure 
E) the collision rate increases 
A) heat is absorbed by the reaction proceeding to the right 
B) the number of molecules on one side is greater than the number on the other side of the balanced equation 
C) the number of molecules increases during the chemical reaction 
D) the gases are impure 
E) the collision rate increases

Question 5

What is the value for Kc for the reaction below if the equilibrium concentrations are [N2] = 0.025 M,[H2] = 0.0013 M and [NH3] = 0.028 M for the following reaction?
N2(g)+ 3 H2(g)⇌ 2 NH3(g)

Accepted Answer

A) 8.6 × 102 
B) 1.4 × 107 
C) 1.2 × 10-3  
D) 7.1 × 10-8 
E) 7.4 × 105  
A) 8.6 × 102 
B) 1.4 × 107 
C) 1.2 × 10-3  
D) 7.1 × 10-8 
E) 7.4 × 105

Question 6

For the decomposition of ammonium carbamate
NH4(NH2CO2)(s)⇌ 2 NH3(g)+ CO2(g)
Kp = 0.0596 at a certain temperature.A solid sample of ammonium carbamate is introduced into an evacuated container and at equilibrium some solid remains in the container.What is the total pressure in the container?

Accepted Answer

A) 0.738 atm 
B) 1.17 atm 
C) 0.930 atm 
D) 0.179 atm 
E) 0.358 atm 
A) 0.738 atm 
B) 1.17 atm 
C) 0.930 atm 
D) 0.179 atm 
E) 0.358 atm

Question 7

For the reaction:
PCl3(g)+ Cl2(g)⇌ PCl5(g)at 70.5 °C,Kp = 1.05.
If one starts with 1.80 atm pressure of PCl3(g),1.72 atm pressure of Cl2(g),and no PCl5(g),what is the partial pressure of PCl5(g)at equilibrium?

Accepted Answer

A) 0.827 atm 
B) 0.856 atm 
C) 0.818 atm 
D) 0.599 atm 
E) 0.080 atm 
A) 0.827 atm 
B) 0.856 atm 
C) 0.818 atm 
D) 0.599 atm 
E) 0.080 atm

Question 8

4.000 mol chlorine and 2.000 mol bromine were placed in a 50.0 L container and kept at 293 K until equilibrium was achieved for the reaction:
Br2(l)+ Cl2(g)⇌ BrCl(g)
At the point of equilibrium there were 82.63 g of Br2(l).Compute the value of Kc for this reaction.

Accepted Answer

A) 0.0699 
B) 1.18 
C) 0.849 
D) 3.50 
E) 2.36 
A) 0.0699 
B) 1.18 
C) 0.849 
D) 3.50 
E) 2.36

Question 9

In the reaction:
2 N2O(g)+ N2H4(g)⇌ 3 N2(g)+ 2 H2O(g),
One starts with 0.10 mol N2O and 0.25 mol N2H4 in a 10.0 L container.If there are 0.06 mol N2O at equilibrium,how many moles of N2 are present?

Accepted Answer

A) 0.02 
B) 0.04 
C) 0.06 
D) 0.09 
E) 0.07 
A) 0.02 
B) 0.04 
C) 0.06 
D) 0.09 
E) 0.07

Question 10

The equilibrium constant Kc is equal to 5.00 L at 1300 K for the reaction:
2 SO2(g)+ O2(g)⇌ 2 SO3(g)
If initial concentrations are [SO2] = 6.00 mol L-1,[O2] = 0.45 mol L-1,and [SO3] = 9.00 mol L-1,the system is:

Accepted Answer

A) at equilibrium 
B) not at equilibrium and will remain in an unequilibrated state 
C) not at equilibrium and will shift to the left to achieve an equilibrium state 
D) not at equilibrium and will shift to the right to achieve an equilibrium state 
A) at equilibrium 
B) not at equilibrium and will remain in an unequilibrated state 
C) not at equilibrium and will shift to the left to achieve an equilibrium state 
D) not at equilibrium and will shift to the right to achieve an equilibrium state

Question 11

What is the value for Kc if [CO] = 0.025 M,[H2] = 0.013 M and [CH3OH] = 0.0028 M for the following reaction?
CH3OH(g)⇌ CO(g)+ 2 H2(g)

Accepted Answer

A) 1.5 × 10-3  
B) 0.12 
C) 6.6 × 102  
D) 8.6 
E) 9.1 × 10-7  
A) 1.5 × 10-3  
B) 0.12 
C) 6.6 × 102  
D) 8.6 
E) 9.1 × 10-7

Question 12

For which of the following reactions does Kp = Kc?

Accepted Answer

A) 3 Fe(s)+ 4 H2O(g)⇌ Fe3O4(s)+ 4 H2(g) 
B) C(s)+ H2O(g)⇌ CO(g)+ H2(g) 
C) 2 SO2(g)+ O2(g)⇌ 2 SO3(g) 
D) H2(g)+ I2(s)⇌ 2 HI(g) 
A) 3 Fe(s)+ 4 H2O(g)⇌ Fe3O4(s)+ 4 H2(g) 
B) C(s)+ H2O(g)⇌ CO(g)+ H2(g) 
C) 2 SO2(g)+ O2(g)⇌ 2 SO3(g) 
D) H2(g)+ I2(s)⇌ 2 HI(g)

Question 13

One of the reactions in the gasification of coal is
CO(g)+ 3 H2(g)⇌ CH4(g)+ H2O(g)ΔrH° = -237 kJ
For each of the following changes,explain the effect (increase,decrease,no effect)on the number of moles of CH4(g)produced.
(a)increase the concentration of H2O(g)
(b)decrease the volume of the container
(c)add a catalyst
(d)decrease the temperature

Accepted Answer

(a)decreas

Question 14

The   For the reaction below is 1.49 × 108 at 100.0 °C:
CO(g)+Cl2(g)→COCl(g)
In an equilibrium mixture of the three gases, PCO=PCl2= 2.22 × 10-4 bar.The partial pressure of the product,phosgene ( COCl2),is ________ bar.

Accepted Answer

A) 7.34 
B) 3.02 × 1015 
C) 3.31 × 10-16 
D) 3.31 × 104 
E) 6.67 × 1011 
A) 7.34 
B) 3.02 × 1015 
C) 3.31 × 10-16 
D) 3.31 × 104 
E) 6.67 × 1011

Question 15

Cyclohexane,C6H12,undergoes a molecular rearrangement in the presence of AlCl3 to form methylcyclopentane,CH3C5H9, according to the equation:
C6H12 ⇌ CH3C5H9
If Kc = 0.143 at 25 °C for this reaction,find the equilibrium concentrations of C6H12 and CH3C5H9 if the initial concentrations are 0.200 mol L-1 and 0.075 mol L-1,respectively.

Accepted Answer

A) [C6H12] = 0.041 mol L-1,[CH3C5H9] = 0.041 mol L-1 
B) [C6H12] = 0.159 mol L-1,[CH3C5H9] = 0.116 mol L-1 
C) [C6H12] = 0.241 mol L-1,[CH3C5H9] = 0.034 mol L-1 
D) [C6H12] = 0.253 mol L-1,[CH3C5H9] = 0.022 mol L-1 
A) [C6H12] = 0.041 mol L-1,[CH3C5H9] = 0.041 mol L-1 
B) [C6H12] = 0.159 mol L-1,[CH3C5H9] = 0.116 mol L-1 
C) [C6H12] = 0.241 mol L-1,[CH3C5H9] = 0.034 mol L-1 
D) [C6H12] = 0.253 mol L-1,[CH3C5H9] = 0.022 mol L-1

Question 16

Consider the following reversible reaction:
POCl3(g)⇌ POCl(g)+ Cl2(g)Kc = 0.450
The following initial amounts of reactants and products were mixed: [POCl3] = 0.750 M,[POCl] = 0.550 M,and [Cl2] = 0.150 M.What is the equilibrium concentration of POCl?

Accepted Answer

A) 0.395 M 
B) 0.155 M 
C) 0.740 M 
D) 0.945 M 
E) 0.360 M 
A) 0.395 M 
B) 0.155 M 
C) 0.740 M 
D) 0.945 M 
E) 0.360 M

Question 17

At a certain temperature,Kc = 0.0500 and △rH° = +39.6 kJ for the reaction below.
2 MgCl2(s)+ O2(g)⇌ 2 MgO(s)+ 2 Cl2(g)
Calculate Kc for the reaction
MgO(s)+ Cl2(g)⇌ MgCl2(s)+ 1/2 O2(g)
And indicate whether its value will be larger or smaller at a lower temperature.

Accepted Answer

A) 4.47,larger 
B) 400,smaller 
C) 0.224,larger 
D) 0.224,smaller 
E) 0.0025,smaller 
A) 4.47,larger 
B) 400,smaller 
C) 0.224,larger 
D) 0.224,smaller 
E) 0.0025,smaller

Question 18

For the reaction: 3 Fe(s)+ 4 H2O(g)⇌ Fe3O4(s)+ 4 H2(g)write the expression for Kc in terms of Kp.

Accepted Answer

A) Kc = Kp  
B) Kc =   
C) Kc = KpRT 
D) Kc =   
E) Kc =     
A) Kc = Kp  
B) Kc =   
C) Kc = KpRT 
D) Kc =   
E) Kc =

Question 19

One method to aid in working out equilibrium problems is the ICE table.

Accepted Answer

A) True 
 B)False

Question 20

At 900.0 K,the equilibrium constant (Kp)for the following reaction is 0.345: 
 +  (g)→   (g)
At equilibrium,the partial pressure of   Is 35.0 bar and that of   Is 15.9 bar.The partial pressure of   Is ________ bar.

Accepted Answer

A) 82.0 
B) 4.21 ×   
C) 192 
D) 6.20 × 10-4 
E) 40.2 
A) 82.0 
B) 4.21 ×   
C) 192 
D) 6.20 × 10-4 
E) 40.2

Exam 15: Principles of Chemical Equilibrium

What is the relationship between Kp and Kc for the reaction below? 4 NH3(g)+ 7 O2(g)⇌ 2 N2O4(g)+ 6 H2O(g)

Write the equilibrium constant expression for the following reaction: 6 CO2(g)+ 6 H2O(l)⇌ C6H12O6(s)+ 6 O2(g)

Consider the equilibrium system: N2O4(g)⇌ 2 NO2(g)for which Kp = 0.1134 at 25 °C and ΔrH° = 58.03 kJ/mol.Assume that 1 mole of N2O4 and 2 moles of NO2 are introduced into a 5.0 liter container.What will be the equilibrium value of [N2O4]?

In a reaction at equilibrium involving only gases,a pressure change will shift the reaction only when:

What is the value for Kc for the reaction below if the equilibrium concentrations are [N2] = 0.025 M,[H2] = 0.0013 M and [NH3] = 0.028 M for the following reaction? N2(g)+ 3 H2(g)⇌ 2 NH3(g)

For the decomposition of ammonium carbamate NH4(NH2CO2)(s)⇌ 2 NH3(g)+ CO2(g) Kp = 0.0596 at a certain temperature.A solid sample of ammonium carbamate is introduced into an evacuated container and at equilibrium some solid remains in the container.What is the total pressure in the container?

For the reaction: PCl3(g)+ Cl2(g)⇌ PCl5(g)at 70.5 °C,Kp = 1.05. If one starts with 1.80 atm pressure of PCl3(g),1.72 atm pressure of Cl2(g),and no PCl5(g),what is the partial pressure of PCl5(g)at equilibrium?

4.000 mol chlorine and 2.000 mol bromine were placed in a 50.0 L container and kept at 293 K until equilibrium was achieved for the reaction: Br2(l)+ Cl2(g)⇌ BrCl(g) At the point of equilibrium there were 82.63 g of Br2(l).Compute the value of Kc for this reaction.

In the reaction: 2 N2O(g)+ N2H4(g)⇌ 3 N2(g)+ 2 H2O(g), One starts with 0.10 mol N2O and 0.25 mol N2H4 in a 10.0 L container.If there are 0.06 mol N2O at equilibrium,how many moles of N2 are present?

The equilibrium constant Kc is equal to 5.00 L at 1300 K for the reaction: 2 SO2(g)+ O2(g)⇌ 2 SO3(g) If initial concentrations are [SO2] = 6.00 mol L-1,[O2] = 0.45 mol L-1,and [SO3] = 9.00 mol L-1,the system is:

What is the value for Kc if [CO] = 0.025 M,[H2] = 0.013 M and [CH3OH] = 0.0028 M for the following reaction? CH3OH(g)⇌ CO(g)+ 2 H2(g)

For which of the following reactions does Kp = Kc?

The For the reaction below is 1.49 × 108 at 100.0 °C: CO(g)+Cl2(g)→COCl(g) In an equilibrium mixture of the three gases, PCO=PCl2= 2.22 × 10-4 bar.The partial pressure of the product,phosgene ( COCl2),is ________ bar.

Consider the following reversible reaction: POCl3(g)⇌ POCl(g)+ Cl2(g)Kc = 0.450 The following initial amounts of reactants and products were mixed: [POCl3] = 0.750 M,[POCl] = 0.550 M,and [Cl2] = 0.150 M.What is the equilibrium concentration of POCl?

At a certain temperature,Kc = 0.0500 and △rH° = +39.6 kJ for the reaction below. 2 MgCl2(s)+ O2(g)⇌ 2 MgO(s)+ 2 Cl2(g) Calculate Kc for the reaction MgO(s)+ Cl2(g)⇌ MgCl2(s)+ 1/2 O2(g) And indicate whether its value will be larger or smaller at a lower temperature.

For the reaction: 3 Fe(s)+ 4 H2O(g)⇌ Fe3O4(s)+ 4 H2(g)write the expression for Kc in terms of Kp.

One method to aid in working out equilibrium problems is the ICE table.

At 900.0 K,the equilibrium constant (Kp)for the following reaction is 0.345: + (g)→ (g) At equilibrium,the partial pressure of Is 35.0 bar and that of Is 15.9 bar.The partial pressure of Is ________ bar.

Matter: Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Valence Bond and Molecular Orbital Theories

Intermolecular Forces: Liquids and Solids

Spontaneous Change: Entropy and Gibbs Energy

Solutions and Their Physical Properties

Acids and Bases

Additional Aspects of Acidbase Equilibria

Solubility and Complex-Ion Equilibria

Electrochemistry

Chemical Kinetics

Chemistry of the Main-Group Elements I: Groups 1,2,13,and 14

Chemistry of the Main-Group Elements Ii: Groups 18,17,16,15,and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

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What is the relationship between K_p and K_c for the reaction below? 4 NH₃(g)+ 7 O₂(g)⇌ 2 N₂O₄(g)+ 6 H₂O(g)

Write the equilibrium constant expression for the following reaction: 6 CO₂(g)+ 6 H₂O(l)⇌ C₆H₁₂O₆(s)+ 6 O₂(g)

Consider the equilibrium system: N₂O₄(g)⇌ 2 NO₂(g)for which K_p = 0.1134 at 25 °C and Δ_rH° = 58.03 kJ/mol.Assume that 1 mole of N₂O₄ and 2 moles of NO₂ are introduced into a 5.0 liter container.What will be the equilibrium value of [N₂O₄]?

What is the value for K_c for the reaction below if the equilibrium concentrations are [N₂] = 0.025 M,[H₂] = 0.0013 M and [NH₃] = 0.028 M for the following reaction? N₂(g)+ 3 H₂(g)⇌ 2 NH₃(g)

For the reaction: PCl₃(g)+ Cl₂(g)⇌ PCl₅(g)at 70.5 °C,K_p = 1.05. If one starts with 1.80 atm pressure of PCl₃(g),1.72 atm pressure of Cl₂(g),and no PCl₅(g),what is the partial pressure of PCl₅(g)at equilibrium?

4.000 mol chlorine and 2.000 mol bromine were placed in a 50.0 L container and kept at 293 K until equilibrium was achieved for the reaction: Br₂(l)+ Cl₂(g)⇌ BrCl(g) At the point of equilibrium there were 82.63 g of Br₂(l).Compute the value of K_c for this reaction.

In the reaction: 2 N₂O(g)+ N₂H₄(g)⇌ 3 N₂(g)+ 2 H₂O(g), One starts with 0.10 mol N₂O and 0.25 mol N₂H₄ in a 10.0 L container.If there are 0.06 mol N₂O at equilibrium,how many moles of N₂ are present?

The equilibrium constant K_c is equal to 5.00 L at 1300 K for the reaction: 2 SO₂(g)+ O₂(g)⇌ 2 SO₃(g) If initial concentrations are [SO₂] = 6.00 mol L^-1,[O₂] = 0.45 mol L^-1,and [SO₃] = 9.00 mol L^-1,the system is:

What is the value for K_c if [CO] = 0.025 M,[H₂] = 0.013 M and [CH₃OH] = 0.0028 M for the following reaction? CH₃OH(g)⇌ CO(g)+ 2 H₂(g)

For which of the following reactions does K_p = K_c?

The For the reaction below is 1.49 × 10⁸ at 100.0 °C: CO(g)+Cl₂(g)→COCl(g) In an equilibrium mixture of the three gases, P_CO=P_Cl₂= 2.22 × 10^-4 bar.The partial pressure of the product,phosgene ( COCl₂),is ________ bar.

Consider the following reversible reaction: POCl₃(g)⇌ POCl(g)+ Cl₂(g)K_c = 0.450 The following initial amounts of reactants and products were mixed: [POCl₃] = 0.750 M,[POCl] = 0.550 M,and [Cl₂] = 0.150 M.What is the equilibrium concentration of POCl?

At a certain temperature,K_c = 0.0500 and △_rH° = +39.6 kJ for the reaction below. 2 MgCl₂(s)+ O₂(g)⇌ 2 MgO(s)+ 2 Cl₂(g) Calculate K_c for the reaction MgO(s)+ Cl₂(g)⇌ MgCl₂(s)+ 1/2 O₂(g) And indicate whether its value will be larger or smaller at a lower temperature.

For the reaction: 3 Fe(s)+ 4 H₂O(g)⇌ Fe₃O₄(s)+ 4 H₂(g)write the expression for K_c in terms of K_p.

At 900.0 K,the equilibrium constant (K_p)for the following reaction is 0.345: + (g)→ (g) At equilibrium,the partial pressure of Is 35.0 bar and that of Is 15.9 bar.The partial pressure of Is ________ bar.