Question 1

Which of the following equilibria would not be affected by pressure change at constant temperature?

Accepted Answer

A)  CO2(g)+ H2(g)   CO(g)+ H2O(g) 
B)  CO(g)+   O2(g)   CO2(g) 
C)  2 Hg(   )+ O2(g)   2 HgO(s) 
D)  2 H2(g)+ O2(g)   2 H2O(   ) 
E)  CaCO3(s)   CaO(s)+ CO2(g) 
A)  CO2(g)+ H2(g)   CO(g)+ H2O(g) 
B)  CO(g)+   O2(g)   CO2(g) 
C)  2 Hg(   )+ O2(g)   2 HgO(s) 
D)  2 H2(g)+ O2(g)   2 H2O(   ) 
E)  CaCO3(s)   CaO(s)+ CO2(g)

Question 2

Nitrosyl bromide decomposes according to the chemical equation below. 2 NOBr(g)   2 NO(g)+ Br2(g)
When 0.260 atm of NOBr is sealed in a flask and allowed to reach equilibrium,22% of the NOBr decomposes.What is the equilibrium constant,Kp,for the reaction?

Accepted Answer

A)  2.3 × 10-3 
B)  4.5 × 10-3 
C)  3.5 × 10-2 
D)  4.8 × 10-2 
E)  8.0 × 10-2 
A)  2.3 × 10-3 
B)  4.5 × 10-3 
C)  3.5 × 10-2 
D)  4.8 × 10-2 
E)  8.0 × 10-2

Question 3

At 800 K,the equilibrium constant,Kp,for the following reaction is 3.2 × 10-7. 2 H2S(g)   2 H2(g)+ S2(g)
A reaction vessel at 800 K initially contains 3.00 atm of H2S.If the reaction is allowed to equilibrate,what is the equilibrium pressure of S2?

Accepted Answer

A)  8.5 × 10-5 atm 
B)  6.2 × 10-3 atm 
C)  9.0 × 10-3 atm 
D)  1.1 × 10-2 atm 
E)  1.4 × 10-2 atm 
A)  8.5 × 10-5 atm 
B)  6.2 × 10-3 atm 
C)  9.0 × 10-3 atm 
D)  1.1 × 10-2 atm 
E)  1.4 × 10-2 atm

Question 4

At 700 K,Kp for the following equilibrium is 5.6 × 10-3. 2HgO(s)   2Hg(l)+ O2(g)
Suppose 43.1 g of mercury(II)oxide is placed in a sealed 4.00-L vessel at 700 K.What is the partial pressure of oxygen gas at equilibrium? (R = 0.0821 L · atm/(K · mol))

Accepted Answer

A)  0.074 atm 
B)  0.0056 atm 
C)  2.8 atm 
D)  14 atm 
E)  1.4 atm 
A)  0.074 atm 
B)  0.0056 atm 
C)  2.8 atm 
D)  14 atm 
E)  1.4 atm

Question 5

For the reaction N2O4(g)   2NO2(g),Kp = 0.148 at a temperature of 298 K.What is Kp for the following reaction? 12NO2(g)   6N2O4(g)

Accepted Answer

A)  9.52 × 104 
B)  0.888 
C)  1.05 × 10-5 
D)  1.13 
E)  6.76 
A)  9.52 × 104 
B)  0.888 
C)  1.05 × 10-5 
D)  1.13 
E)  6.76

Question 6

Sulfuryl chloride decomposes to sulfur dioxide and chlorine. SO2Cl2(g)   SO2(g)+ Cl2(g)
Kc is 0.045 at 648 K.If an initial concentration of 0.075 M SO2Cl2 is allowed to equilibrate,what is the equilibrium concentration of Cl2?

Accepted Answer

A)  0.0034 M 
B)  0.030 M 
C)  0.040 M 
D)  0.058 M 
E)  0.075 M 
A)  0.0034 M 
B)  0.030 M 
C)  0.040 M 
D)  0.058 M 
E)  0.075 M

Question 7

Which of the following expressions correctly describes the equilibrium constant Kc for the reaction given below? 2 C2H2(g)+ 5 O2(g)   4 CO2(g)+ 2 H2O(g)

Accepted Answer

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

Question 8

The equilibrium constant at 25 °C for the dissolution of silver iodide is 8.5 × 10-17. AgI(s)   Ag+(aq)+ I-(aq)
If an excess quantity of AgI(s)is added to water and allowed to equilibrate,what is the equilibrium concentration of I-?

Accepted Answer

A)  7.2 × 10-33 M 
B)  4.3 × 10-17 M 
C)  8.5 × 10-17 M 
D)  6.5 × 10-9 M 
E)  9.2 × 10-9 M 
A)  7.2 × 10-33 M 
B)  4.3 × 10-17 M 
C)  8.5 × 10-17 M 
D)  6.5 × 10-9 M 
E)  9.2 × 10-9 M

Question 9

Which of the following statements about the reaction quotient,Q,is false?

Accepted Answer

A)  The value of Q can be used to predict equilibrium concentrations. 
B)  It has the same expression as Kc. 
C)  Its value is calculated using nonequilibrium concentrations. 
D)  If Q > Kc,the reaction must move to equilibrium by forming more reactants. 
E)  If Q c,the reaction must move to equilibrium by forming more products. 
A)  The value of Q can be used to predict equilibrium concentrations. 
B)  It has the same expression as Kc. 
C)  Its value is calculated using nonequilibrium concentrations. 
D)  If Q > Kc,the reaction must move to equilibrium by forming more reactants. 
E)  If Q c,the reaction must move to equilibrium by forming more products.

Question 10

In an experiment,0.46 mol H2 and 0.46 mol I2 are mixed in a 1.00-L container,and the reaction forms HI.If Kc = 49.for this reaction,what is the equilibrium concentration of HI? I2(g)+ H2(g)   2HI(g)

Accepted Answer

A)  0.88 M 
B)  0.81 M 
C)  0.72 M 
D)  0.115 M 
E)  0.061 M 
A)  0.88 M 
B)  0.81 M 
C)  0.72 M 
D)  0.115 M 
E)  0.061 M

Question 11

At 25 °C,the decomposition of dinitrogen tetraoxide N2O4(g)   2 NO2(g)
Has an equilibrium constant (Kp)of 0.144.At equilibrium,the total pressure of the system is 0.0758 atm.What is the partial pressure of each gas?

Accepted Answer

A)  0.0745 atm NO2(g)and 0.0385 N2O4(g) 
B)  0.0549 atm NO2(g)and 0.0209 N2O4(g) 
C)  0.0531 atm NO2(g)and 0.0227 N2O4(g) 
D)  0.0502 atm NO2(g)and 0.0256 N2O4(g) 
E)  0.0381 atm NO2(g)and 0.0377 N2O4(g) 
A)  0.0745 atm NO2(g)and 0.0385 N2O4(g) 
B)  0.0549 atm NO2(g)and 0.0209 N2O4(g) 
C)  0.0531 atm NO2(g)and 0.0227 N2O4(g) 
D)  0.0502 atm NO2(g)and 0.0256 N2O4(g) 
E)  0.0381 atm NO2(g)and 0.0377 N2O4(g)

Question 12

An aqueous mixture of phenol and ammonia has initial concentrations of 0.200 M C6H5OH(aq)and 0.120 M NH3(aq).At equilibrium,the C6H5O-(aq)concentration is 0.050 M.Calculate the equilibrium constant,K,for the reaction below. C6H5OH(aq)+ NH3(aq)   C6H5O- + NH4+(aq)

Accepted Answer

A)  0.10 
B)  0.24 
C)  2.1 
D)  4.2 
E)  4.8 
A)  0.10 
B)  0.24 
C)  2.1 
D)  4.2 
E)  4.8

Question 13

Given the following chemical equilibria, N2(g)+ O2(g)   2 NO(g)
K1
N2(g)+ 3 H2(g)   2 NH3(g)
K2
H2(g)+ 1/2 O2(g)   H2O(g)
K3
Determine the method used to calculate the equilibrium constant for the reaction below.
4 NH3(g)+ 5 O2(g)   4 NO(g)+ 6 H2O(g)
K c

Accepted Answer

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

Question 14

For the equilibrium PCl5(g)   PCl3(g)+ Cl2(g),Kc = 2.0 × 101 at 240°C.If pure PCl5 is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl3(g)is 0.50 M,what is the equilibrium concentration of PCl5(g)?

Accepted Answer

A)  1 M 
B)  0.25 M 
C)  0.025 M 
D)  0.012 M 
E)  6.3 M 
A)  1 M 
B)  0.25 M 
C)  0.025 M 
D)  0.012 M 
E)  6.3 M

Question 15

For which of the following reactions is Kc = Kp?

Accepted Answer

A)  N2(g)+ 3 H2(g)   2 NH3(g) 
B)  CO(g)+ H2O(g)   CO2(g)+ H2(g) 
C)  CO(g)+ 3 H2(g)   CH4(g)+ H2O(g) 
D)  CaO(s)+ CO2(g)   CaCO3(s) 
E)  HBr(g)   ½ H2(g)+ ½ Br2(   ) 
A)  N2(g)+ 3 H2(g)   2 NH3(g) 
B)  CO(g)+ H2O(g)   CO2(g)+ H2(g) 
C)  CO(g)+ 3 H2(g)   CH4(g)+ H2O(g) 
D)  CaO(s)+ CO2(g)   CaCO3(s) 
E)  HBr(g)   ½ H2(g)+ ½ Br2(   )

Question 16

Given the following chemical equilibrium COCl2(g)   CO(g)+ Cl2(g),calculate the value of Kc when Kp = 6.5 × 1011 at 298 K.(R = 0.08206 L⋅atm/mol ⋅ K)

Accepted Answer

A)  1.5 × 10-12 
B)  3.8 × 10-11 
C)  1.1 × 109 
D)  2.7 × 1010 
E)  1.6 × 1013 
A)  1.5 × 10-12 
B)  3.8 × 10-11 
C)  1.1 × 109 
D)  2.7 × 1010 
E)  1.6 × 1013

Question 17

Exactly 1.0 mol N2O4 is placed in an empty 1.0-L container and allowed to reach equilibrium described by the equation N2O4(g)   2NO2(g). If at equilibrium the N2O4 is 27.0% dissociated,what is the value of the equilibrium constant,Kc,for the reaction under these conditions?

Accepted Answer

A)  0.40 
B)  2.5 
C)  0.29 
D)  0.74 
E)  0.10 
A)  0.40 
B)  2.5 
C)  0.29 
D)  0.74 
E)  0.10

Question 18

If the reaction quotient,Q,is greater than K in a gas phase reaction,then

Accepted Answer

A)  the chemical system has reached equilibrium. 
B)  the temperature must be increased for the reaction to proceed in the forward direction. 
C)  the reaction will proceed in the forward direction until equilibrium is established. 
D)  the reaction will proceed in the backward direction until equilibrium is established. 
E)  the reaction will proceed in the direction that increases the number of gas phase particles. 
A)  the chemical system has reached equilibrium. 
B)  the temperature must be increased for the reaction to proceed in the forward direction. 
C)  the reaction will proceed in the forward direction until equilibrium is established. 
D)  the reaction will proceed in the backward direction until equilibrium is established. 
E)  the reaction will proceed in the direction that increases the number of gas phase particles.

Question 19

If a stress is applied to an equilibrium system,the system will respond in such a way as to relieve that stress.This is a statement of ________ principle.

Accepted Answer

The answer of If a stress is applied to an...

Question 20

Consider the reaction H2 + I2   2HI for which Kc = 44.0 at a high temperature.If an equimolar mixture of reactants gives the concentration of the product to be 0.50 M at equilibrium,determine the equilibrium concentration of the hydrogen.

Accepted Answer

A)  7.5 × 10-2 M 
B)  1.1 × 10-1 M 
C)  3.8 × 10-2 M 
D)  1.3 × 101 M 
E)  5.7 × 10-3 M 
A)  7.5 × 10-2 M 
B)  1.1 × 10-1 M 
C)  3.8 × 10-2 M 
D)  1.3 × 101 M 
E)  5.7 × 10-3 M

Exam 16: Principles of Chemical Reactivity: Equilibria

Which of the following equilibria would not be affected by pressure change at constant temperature?

Nitrosyl bromide decomposes according to the chemical equation below. 2 NOBr(g) 2 NO(g)+ Br2(g) When 0.260 atm of NOBr is sealed in a flask and allowed to reach equilibrium,22% of the NOBr decomposes.What is the equilibrium constant,Kp,for the reaction?

At 800 K,the equilibrium constant,Kp,for the following reaction is 3.2 × 10-7. 2 H2S(g) 2 H2(g)+ S2(g) A reaction vessel at 800 K initially contains 3.00 atm of H2S.If the reaction is allowed to equilibrate,what is the equilibrium pressure of S2?

At 700 K,Kp for the following equilibrium is 5.6 × 10-3. 2HgO(s) 2Hg(l)+ O2(g) Suppose 43.1 g of mercury(II)oxide is placed in a sealed 4.00-L vessel at 700 K.What is the partial pressure of oxygen gas at equilibrium? (R = 0.0821 L · atm/(K · mol))

For the reaction N2O4(g) 2NO2(g),Kp = 0.148 at a temperature of 298 K.What is Kp for the following reaction? 12NO2(g) 6N2O4(g)

Sulfuryl chloride decomposes to sulfur dioxide and chlorine. SO2Cl2(g) SO2(g)+ Cl2(g) Kc is 0.045 at 648 K.If an initial concentration of 0.075 M SO2Cl2 is allowed to equilibrate,what is the equilibrium concentration of Cl2?

Which of the following expressions correctly describes the equilibrium constant Kc for the reaction given below? 2 C2H2(g)+ 5 O2(g) 4 CO2(g)+ 2 H2O(g)

The equilibrium constant at 25 °C for the dissolution of silver iodide is 8.5 × 10-17. AgI(s) Ag+(aq)+ I-(aq) If an excess quantity of AgI(s)is added to water and allowed to equilibrate,what is the equilibrium concentration of I-?

Which of the following statements about the reaction quotient,Q,is false?

In an experiment,0.46 mol H2 and 0.46 mol I2 are mixed in a 1.00-L container,and the reaction forms HI.If Kc = 49.for this reaction,what is the equilibrium concentration of HI? I2(g)+ H2(g) 2HI(g)

At 25 °C,the decomposition of dinitrogen tetraoxide N2O4(g) 2 NO2(g) Has an equilibrium constant (Kp)of 0.144.At equilibrium,the total pressure of the system is 0.0758 atm.What is the partial pressure of each gas?

An aqueous mixture of phenol and ammonia has initial concentrations of 0.200 M C6H5OH(aq)and 0.120 M NH3(aq).At equilibrium,the C6H5O-(aq)concentration is 0.050 M.Calculate the equilibrium constant,K,for the reaction below. C6H5OH(aq)+ NH3(aq) C6H5O- + NH4+(aq)

Given the following chemical equilibria, N2(g)+ O2(g) 2 NO(g) K1 N2(g)+ 3 H2(g) 2 NH3(g) K2 H2(g)+ 1/2 O2(g) H2O(g) K3 Determine the method used to calculate the equilibrium constant for the reaction below. 4 NH3(g)+ 5 O2(g) 4 NO(g)+ 6 H2O(g) K c

For the equilibrium PCl5(g) PCl3(g)+ Cl2(g),Kc = 2.0 × 101 at 240°C.If pure PCl5 is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl3(g)is 0.50 M,what is the equilibrium concentration of PCl5(g)?

For which of the following reactions is Kc = Kp?

Given the following chemical equilibrium COCl2(g) CO(g)+ Cl2(g),calculate the value of Kc when Kp = 6.5 × 1011 at 298 K.(R = 0.08206 L⋅atm/mol ⋅ K)

Exactly 1.0 mol N2O4 is placed in an empty 1.0-L container and allowed to reach equilibrium described by the equation N2O4(g) 2NO2(g). If at equilibrium the N2O4 is 27.0% dissociated,what is the value of the equilibrium constant,Kc,for the reaction under these conditions?

If the reaction quotient,Q,is greater than K in a gas phase reaction,then

If a stress is applied to an equilibrium system,the system will respond in such a way as to relieve that stress.This is a statement of ________ principle.

Consider the reaction H2 + I2 2HI for which Kc = 44.0 at a high temperature.If an equimolar mixture of reactants gives the concentration of the product to be 0.50 M at equilibrium,determine the equilibrium concentration of the hydrogen.

Basic Concepts of Chemistry

Lets Review: The Tools of Quantitative Chemistry

Atoms, molecules, and Ions

Chemical Reactions

Stoichiometry: Quantitative Information About Chemical Reactions

Principles of Chemical Reactivity: Energy and Chemical Reactions

The Structure of Atoms

The Structure of Atoms and Periodic Trends

Bonding and Molecular Structure

Bonding and Molecular Structure Orbital Hybridization and Molecular Orbitals

Gases and Their Properties

Intermolecular Forces and Liquids

The Solid State

Solutions and Their Behavior

Chemical Kinetics: the Rates of Chemical Reactions

Principles of Chemical Reactivity: the Chemistry of Acids and Bases

Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

Principles of Chemical Reactivity: Entropy and Free Energy

Principles of Chemical Reactivity: Electron Transfer Reactions

Environmental Chemistry: Earths Environment, energy, and Sustainability

The Chemistry of the Main Group Elements

The Chemistry of the Transition Elements

Carbon: Not Just Another Element

Biochemistry

Nuclear Chemistry

Filters

Nitrosyl bromide decomposes according to the chemical equation below. 2 NOBr(g) 2 NO(g)+ Br₂(g) When 0.260 atm of NOBr is sealed in a flask and allowed to reach equilibrium,22% of the NOBr decomposes.What is the equilibrium constant,K_p,for the reaction?

At 800 K,the equilibrium constant,K_p,for the following reaction is 3.2 × 10^-7. 2 H₂S(g) 2 H₂(g)+ S₂(g) A reaction vessel at 800 K initially contains 3.00 atm of H₂S.If the reaction is allowed to equilibrate,what is the equilibrium pressure of S₂?

At 700 K,K_p for the following equilibrium is 5.6 × 10^-3. 2HgO(s) 2Hg(l)+ O₂(g) Suppose 43.1 g of mercury(II)oxide is placed in a sealed 4.00-L vessel at 700 K.What is the partial pressure of oxygen gas at equilibrium? (R = 0.0821 L · atm/(K · mol))

For the reaction N₂O₄(g) 2NO₂(g),K_p = 0.148 at a temperature of 298 K.What is K_p for the following reaction? 12NO₂(g) 6N₂O₄(g)

Sulfuryl chloride decomposes to sulfur dioxide and chlorine. SO₂Cl₂(g) SO₂(g)+ Cl₂(g) K_c is 0.045 at 648 K.If an initial concentration of 0.075 M SO₂Cl₂ is allowed to equilibrate,what is the equilibrium concentration of Cl₂?

Which of the following expressions correctly describes the equilibrium constant K_c for the reaction given below? 2 C₂H₂(g)+ 5 O₂(g) 4 CO₂(g)+ 2 H₂O(g)

The equilibrium constant at 25 °C for the dissolution of silver iodide is 8.5 × 10^-17. AgI(s) Ag⁺(aq)+ I^-(aq) If an excess quantity of AgI(s)is added to water and allowed to equilibrate,what is the equilibrium concentration of I^-?

In an experiment,0.46 mol H₂ and 0.46 mol I₂ are mixed in a 1.00-L container,and the reaction forms HI.If K_c = 49.for this reaction,what is the equilibrium concentration of HI? I₂(g)+ H₂(g) 2HI(g)

At 25 °C,the decomposition of dinitrogen tetraoxide N₂O₄(g) 2 NO₂(g) Has an equilibrium constant (K_p)of 0.144.At equilibrium,the total pressure of the system is 0.0758 atm.What is the partial pressure of each gas?

An aqueous mixture of phenol and ammonia has initial concentrations of 0.200 M C₆H₅OH(aq)and 0.120 M NH₃(aq).At equilibrium,the C₆H₅O^-(aq)concentration is 0.050 M.Calculate the equilibrium constant,K,for the reaction below. C₆H₅OH(aq)+ NH₃(aq) C₆H₅O^- + NH₄⁺(aq)

Given the following chemical equilibria, N₂(g)+ O₂(g) 2 NO(g) K₁ N₂(g)+ 3 H₂(g) 2 NH₃(g) K₂ H₂(g)+ 1/2 O₂(g) H₂O(g) K₃ Determine the method used to calculate the equilibrium constant for the reaction below. 4 NH₃(g)+ 5 O₂(g) 4 NO(g)+ 6 H₂O(g) K _c

For the equilibrium PCl₅(g) PCl₃(g)+ Cl₂(g),K_c = 2.0 × 10¹ at 240°C.If pure PCl₅ is placed in a 1.00-L container and allowed to come to equilibrium,and the equilibrium concentration of PCl₃(g)is 0.50 M,what is the equilibrium concentration of PCl₅(g)?

For which of the following reactions is K_c = K_p?

Given the following chemical equilibrium COCl₂(g) CO(g)+ Cl₂(g),calculate the value of K_cwhen K_p = 6.5 × 10¹¹ at 298 K.(R = 0.08206 L⋅atm/mol ⋅ K)

Exactly 1.0 mol N₂O₄ is placed in an empty 1.0-L container and allowed to reach equilibrium described by the equation N₂O₄(g) 2NO₂(g). If at equilibrium the N₂O₄ is 27.0% dissociated,what is the value of the equilibrium constant,K_c,for the reaction under these conditions?

Consider the reaction H₂ + I₂ 2HI for which K_c = 44.0 at a high temperature.If an equimolar mixture of reactants gives the concentration of the product to be 0.50 M at equilibrium,determine the equilibrium concentration of the hydrogen.