Question 1

Consider the reaction N2(g)+ 3H2(g)   2NH3(g). If hydrogen gas is added to this system at equilibrium, which direction will the reaction shift?

Accepted Answer

The reaction will shift toward the products.

Question 2

The equilibrium constant expression for the reaction 2BrF5(g)   Br2(g)+ 5F2(g)is

Accepted Answer

A) Kc = [Br2] [F2] / [BrF5] 
B) Kc = [Br2] [F2]5 / [BrF5]2 
C) Kc = [Br2] [F2]2 / [BrF5]5 
D) Kc = [BrF5]2 / [Br2][F2]5 
E) Kc = 2[BrF5]2 / ([Br2] * 5[F2]5) 
A) Kc = [Br2] [F2] / [BrF5] 
B) Kc = [Br2] [F2]5 / [BrF5]2 
C) Kc = [Br2] [F2]2 / [BrF5]5 
D) Kc = [BrF5]2 / [Br2][F2]5 
E) Kc = 2[BrF5]2 / ([Br2] * 5[F2]5) B

Question 3

At 35ºC, the equilibrium constant for the reaction 2NOCl(g)   2NO(g)+ Cl2(g)is Kc = 1.6 *10-5. An equilibrium mixture was found to have the following concentrations of Cl2 and NOCl: [Cl2] = 1.2 * 10-2 M; [NOCl] = 2.8 * 10-1 M. Calculate the concentration of NO(g)at equilibrium.

Accepted Answer

A) 1.0 * 10-4 M 
B) 1.0 * 10-2 M 
C) 2.8 * 10-1 M 
D) 2.4 * 10-2 M 
E) 1.6 * 10-3 M 
A) 1.0 * 10-4 M 
B) 1.0 * 10-2 M 
C) 2.8 * 10-1 M 
D) 2.4 * 10-2 M 
E) 1.6 * 10-3 M B

Question 4

The equilibrium between carbon dioxide gas and carbonic acid is very important in biology and environmental science.
CO2(aq)+ H2O(l)    H2CO3(aq)
Based on the equilibrium constant reported for this reaction (Kc = 1.70 * 10-3), there will be more carbon dioxide in solution than carbonic acid.

Accepted Answer

A) True 
 B)False

Question 5

The equilibrium between carbon dioxide gas and carbonic acid is very important in biology and environmental science. CO2(aq)+ H2O(l)    H2CO3(aq)
Which one of the following is the correct equilibrium constant expression (Kc)for this reaction?

Accepted Answer

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

Question 6

At 340 K, Kp = 69 for the reaction H2(g)+ I2(g)    2HI(g). 50.0 g of HI is injected into an evacuated 5.00-L rigid cylinder at 340 K. What is the total pressure inside the cylinder when the system comes to equilibrium?

Accepted Answer

A) 2.60 atm 
B) 1.76 atm 
C) 0.424 atm 
D) 2.18 atm 
E) 10.9 atm 
A) 2.60 atm 
B) 1.76 atm 
C) 0.424 atm 
D) 2.18 atm 
E) 10.9 atm

Question 7

Which is the correct equilibrium constant expression for the following reaction? Fe2O3(s)+ 3H2(g)    2Fe(s)+ 3H2O(g)

Accepted Answer

A) Kc = [Fe2O3] [H2]3 / [Fe]2[H2O]3 
B) Kc = [H2] / [H2O] 
C) Kc = [H2O]3 / [H2]3 
D) Kc = [Fe]2[H2O]3 / [Fe2O3] [H2]3 
E) Kc = [Fe] [H2O] / [Fe2O3] [H2] 
A) Kc = [Fe2O3] [H2]3 / [Fe]2[H2O]3 
B) Kc = [H2] / [H2O] 
C) Kc = [H2O]3 / [H2]3 
D) Kc = [Fe]2[H2O]3 / [Fe2O3] [H2]3 
E) Kc = [Fe] [H2O] / [Fe2O3] [H2]

Question 8

What conditions are used in the Haber process to enhance the yield of ammonia? Explain why each condition affects the yield in terms of the Le Châtelier principle.

Accepted Answer

High pressure, low temperature, use of a

Question 9

Kc for the reaction CO2(g)+ H2(g)   H2O(g)+ CO(g)is 1.6 at about 990ºC. Calculate the number of moles of carbon dioxide in the final equilibrium system obtained by initially adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Accepted Answer

Question 10

Hydrogen iodide decomposes according to the equation:
2HI(g)   H2(g)+ I2(g), Kc = 0.0156 at 400ºC
A 0.660 mol sample of HI was injected into a 2.00 L reaction vessel held at 400ºC.
Calculate the concentration of HI at equilibrium.

Accepted Answer

Question 11

The equilibrium constants for the chemical reaction N2(g)+ O2(g)   2NO(g)are KP = 1.1 * 10-3 and 3.6 *10-3 at 2,200 K and 2,500 K, respectively. Which one of these statements is true?

Accepted Answer

A) The reaction is exothermic, $\Delta$Hº P is less than Kc by a factor of (RT). 
D) The total pressure at 2,200 K is the same as at 2,500 K. 
E) Higher total pressure shifts the equilibrium to the left. 
A) The reaction is exothermic, $\Delta$Hº P is less than Kc by a factor of (RT). 
D) The total pressure at 2,200 K is the same as at 2,500 K. 
E) Higher total pressure shifts the equilibrium to the left.

Question 12

If the system 3H2(g)+ N2(g)   2NH3(g)is at equilibrium and more N2 is added, a net reaction that consumes some of the added N2 will occur until a new equilibrium is reached.

Accepted Answer

A) True 
 B)False

Question 13

Consider the reaction N2(g)+ 3H2(g)   2NH3(g). The production of ammonia is an endothermic reaction. Will heating the equilibrium system increase or decrease the amount of ammonia produced?

Accepted Answer

The amount

Question 14

For the reaction SO2(g)+ NO2(g)   SO3(g)+ NO(g), the equilibrium constant is 18.0 at 1,200ºC. If 1.0 mole of SO2 and 2.0 moles of NO2 are placed in a 20. L container, what concentration of SO3 will be present at equilibrium?

Accepted Answer

A) 0.48 mol/L 
B) 0.11 mol/L 
C) 0.95 mol/L 
D) 2.22 mol/L 
E) 18 mol/L 
A) 0.48 mol/L 
B) 0.11 mol/L 
C) 0.95 mol/L 
D) 2.22 mol/L 
E) 18 mol/L

Question 15

Consider the reaction N2(g)+ 3H2(g)   2NH3(g). If nitrogen is removed from the system at equilibrium, what will happen to the hydrogen (H2)concentration?

Accepted Answer

Question 16

For the reaction H2(g)+ I2(g)   2HI(g), Kc = 50.2 at 445ºC. If [H2] = [I2] = [HI] = 1.75 * 10-3 M at 445ºC, which one of these statements is true?

Accepted Answer

A) The system is at equilibrium, thus no concentration changes will occur. 
B) The concentrations of HI and I2 will increase as the system approaches equilibrium. 
C) The concentration of HI will increase as the system approaches equilibrium. 
D) The concentrations of H2 and HI will fall as the system moves toward equilibrium. 
E) The concentrations of H2 and I2 will increase as the system approaches equilibrium. 
A) The system is at equilibrium, thus no concentration changes will occur. 
B) The concentrations of HI and I2 will increase as the system approaches equilibrium. 
C) The concentration of HI will increase as the system approaches equilibrium. 
D) The concentrations of H2 and HI will fall as the system moves toward equilibrium. 
E) The concentrations of H2 and I2 will increase as the system approaches equilibrium.

Question 17

Consider the reaction N2(g)+ 3H2(g)   2NH3(g). If nitrogen is added to the system at equilibrium, what will happen to the ammonia concentration?

Accepted Answer

Question 18

Kc for the reaction CO2(g)+ H2(g)   H2O(g)+ CO(g)is 1.6 at about 990ºC. Calculate the number of moles of hydrogen gas in the final equilibrium system obtained by initially adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Accepted Answer

Question 19

Consider the reaction N2(g)+ O2(g)   2NO(g), for which Kc = 0.10 at 2,000ºC. Starting with initial concentrations of 0.040 M of N2 and 0.040 M of O2, determine the equilibrium concentration of NO.

Accepted Answer

A) 5.4 * 10-3 M 
B) 0.0096 M 
C) 0.011 M 
D) 0.080 M 
E) 0.10 M 
A) 5.4 * 10-3 M 
B) 0.0096 M 
C) 0.011 M 
D) 0.080 M 
E) 0.10 M

Question 20

When the following reaction is at equilibrium, which of these relationships is always true? 
2NOCl(g)   2NO(g)+ Cl2(g)

Accepted Answer

A) [NO] [Cl2] = [NOCl] 
B) [NO]2 [Cl2] = [NOCl]2 
C) [NOCl] = [NO] 
D) 2[NO] = [Cl2] 
E) [NO]2 [Cl2] = Kc[NOCl]2 
A) [NO] [Cl2] = [NOCl] 
B) [NO]2 [Cl2] = [NOCl]2 
C) [NOCl] = [NO] 
D) 2[NO] = [Cl2] 
E) [NO]2 [Cl2] = Kc[NOCl]2

Exam 15: Chemical Equilibrium

Consider the reaction N2(g)+ 3H2(g) 2NH3(g). If hydrogen gas is added to this system at equilibrium, which direction will the reaction shift?

The equilibrium constant expression for the reaction 2BrF5(g) Br2(g)+ 5F2(g)is

At 35ºC, the equilibrium constant for the reaction 2NOCl(g) 2NO(g)+ Cl2(g)is Kc = 1.6 *10-5. An equilibrium mixture was found to have the following concentrations of Cl2 and NOCl: [Cl2] = 1.2 * 10-2 M; [NOCl] = 2.8 * 10-1 M. Calculate the concentration of NO(g)at equilibrium.

The equilibrium between carbon dioxide gas and carbonic acid is very important in biology and environmental science. CO2(aq)+ H2O(l) H2CO3(aq) Based on the equilibrium constant reported for this reaction (Kc = 1.70 * 10-3), there will be more carbon dioxide in solution than carbonic acid.

The equilibrium between carbon dioxide gas and carbonic acid is very important in biology and environmental science. CO2(aq)+ H2O(l) H2CO3(aq) Which one of the following is the correct equilibrium constant expression (Kc)for this reaction?

At 340 K, Kp = 69 for the reaction H2(g)+ I2(g) 2HI(g). 50.0 g of HI is injected into an evacuated 5.00-L rigid cylinder at 340 K. What is the total pressure inside the cylinder when the system comes to equilibrium?

Which is the correct equilibrium constant expression for the following reaction? Fe2O3(s)+ 3H2(g) 2Fe(s)+ 3H2O(g)

What conditions are used in the Haber process to enhance the yield of ammonia? Explain why each condition affects the yield in terms of the Le Châtelier principle.

Kc for the reaction CO2(g)+ H2(g) H2O(g)+ CO(g)is 1.6 at about 990ºC. Calculate the number of moles of carbon dioxide in the final equilibrium system obtained by initially adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Hydrogen iodide decomposes according to the equation: 2HI(g) H2(g)+ I2(g), Kc = 0.0156 at 400ºC A 0.660 mol sample of HI was injected into a 2.00 L reaction vessel held at 400ºC. Calculate the concentration of HI at equilibrium.

The equilibrium constants for the chemical reaction N2(g)+ O2(g) 2NO(g)are KP = 1.1 * 10-3 and 3.6 *10-3 at 2,200 K and 2,500 K, respectively. Which one of these statements is true?

If the system 3H2(g)+ N2(g) 2NH3(g)is at equilibrium and more N2 is added, a net reaction that consumes some of the added N2 will occur until a new equilibrium is reached.

Consider the reaction N2(g)+ 3H2(g) 2NH3(g). The production of ammonia is an endothermic reaction. Will heating the equilibrium system increase or decrease the amount of ammonia produced?

For the reaction SO2(g)+ NO2(g) SO3(g)+ NO(g), the equilibrium constant is 18.0 at 1,200ºC. If 1.0 mole of SO2 and 2.0 moles of NO2 are placed in a 20. L container, what concentration of SO3 will be present at equilibrium?

Consider the reaction N2(g)+ 3H2(g) 2NH3(g). If nitrogen is removed from the system at equilibrium, what will happen to the hydrogen (H2)concentration?

For the reaction H2(g)+ I2(g) 2HI(g), Kc = 50.2 at 445ºC. If [H2] = [I2] = [HI] = 1.75 * 10-3 M at 445ºC, which one of these statements is true?

Consider the reaction N2(g)+ 3H2(g) 2NH3(g). If nitrogen is added to the system at equilibrium, what will happen to the ammonia concentration?

Kc for the reaction CO2(g)+ H2(g) H2O(g)+ CO(g)is 1.6 at about 990ºC. Calculate the number of moles of hydrogen gas in the final equilibrium system obtained by initially adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Consider the reaction N2(g)+ O2(g) 2NO(g), for which Kc = 0.10 at 2,000ºC. Starting with initial concentrations of 0.040 M of N2 and 0.040 M of O2, determine the equilibrium concentration of NO.

When the following reaction is at equilibrium, which of these relationships is always true? 2NOCl(g) 2NO(g)+ Cl2(g)

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

Energy Relationships in Chemical Reactions

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Thermodynamics

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

Consider the reaction N₂(g)+ 3H₂(g) 2NH₃(g). If hydrogen gas is added to this system at equilibrium, which direction will the reaction shift?

The equilibrium constant expression for the reaction 2BrF₅(g) Br₂(g)+ 5F₂(g)is

At 35ºC, the equilibrium constant for the reaction 2NOCl(g) 2NO(g)+ Cl₂(g)is K_c = 1.6 10^-5. An equilibrium mixture was found to have the following concentrations of Cl₂ and NOCl: [Cl₂] = 1.2 10^-2M; [NOCl] = 2.8 * 10^-1M. Calculate the concentration of NO(g)at equilibrium.

The equilibrium between carbon dioxide gas and carbonic acid is very important in biology and environmental science. CO₂(aq)+ H₂O(l) H₂CO₃(aq) Based on the equilibrium constant reported for this reaction (K_c = 1.70 * 10^-3), there will be more carbon dioxide in solution than carbonic acid.

The equilibrium between carbon dioxide gas and carbonic acid is very important in biology and environmental science. CO₂(aq)+ H₂O(l) H₂CO₃(aq) Which one of the following is the correct equilibrium constant expression (K_c)for this reaction?

At 340 K, K_p = 69 for the reaction H₂(g)+ I₂(g) 2HI(g). 50.0 g of HI is injected into an evacuated 5.00-L rigid cylinder at 340 K. What is the total pressure inside the cylinder when the system comes to equilibrium?

Which is the correct equilibrium constant expression for the following reaction? Fe₂O₃(s)+ 3H₂(g) 2Fe(s)+ 3H₂O(g)

K_c for the reaction CO₂(g)+ H₂(g) H₂O(g)+ CO(g)is 1.6 at about 990ºC. Calculate the number of moles of carbon dioxide in the final equilibrium system obtained by initially adding 1.00 mol of H₂, 2.00 mol of CO₂, 0.750 mol of H₂O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Hydrogen iodide decomposes according to the equation: 2HI(g) H₂(g)+ I₂(g), K_c = 0.0156 at 400ºC A 0.660 mol sample of HI was injected into a 2.00 L reaction vessel held at 400ºC. Calculate the concentration of HI at equilibrium.

The equilibrium constants for the chemical reaction N₂(g)+ O₂(g) 2NO(g)are K_P = 1.1 * 10^-3 and 3.6 *10^-3 at 2,200 K and 2,500 K, respectively. Which one of these statements is true?

If the system 3H₂(g)+ N₂(g) 2NH₃(g)is at equilibrium and more N₂ is added, a net reaction that consumes some of the added N₂ will occur until a new equilibrium is reached.

Consider the reaction N₂(g)+ 3H₂(g) 2NH₃(g). The production of ammonia is an endothermic reaction. Will heating the equilibrium system increase or decrease the amount of ammonia produced?

For the reaction SO₂(g)+ NO₂(g) SO₃(g)+ NO(g), the equilibrium constant is 18.0 at 1,200ºC. If 1.0 mole of SO₂ and 2.0 moles of NO₂ are placed in a 20. L container, what concentration of SO₃ will be present at equilibrium?

Consider the reaction N₂(g)+ 3H₂(g) 2NH₃(g). If nitrogen is removed from the system at equilibrium, what will happen to the hydrogen (H₂)concentration?

For the reaction H₂(g)+ I₂(g) 2HI(g), K_c = 50.2 at 445ºC. If [H₂] = [I₂] = [HI] = 1.75 * 10^-3 M at 445ºC, which one of these statements is true?

Consider the reaction N₂(g)+ 3H₂(g) 2NH₃(g). If nitrogen is added to the system at equilibrium, what will happen to the ammonia concentration?

K_c for the reaction CO₂(g)+ H₂(g) H₂O(g)+ CO(g)is 1.6 at about 990ºC. Calculate the number of moles of hydrogen gas in the final equilibrium system obtained by initially adding 1.00 mol of H₂, 2.00 mol of CO₂, 0.750 mol of H₂O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Consider the reaction N₂(g)+ O₂(g) 2NO(g), for which K_c = 0.10 at 2,000ºC. Starting with initial concentrations of 0.040 M of N₂ and 0.040 M of O₂, determine the equilibrium concentration of NO.

When the following reaction is at equilibrium, which of these relationships is always true? 2NOCl(g) 2NO(g)+ Cl₂(g)