Question 1

In a chemical reaction, if the starting concentrations of reactants are increased, then the equilibrium constant Kc will also increase.

Accepted Answer

A) True 
 B)False

Question 2

Nitric oxide and bromine were allowed to react in a sealed container. When equilibrium was reached PNO = 0.526 atm,   = 1.59 atm, and PNOBr = 7.68 atm. Calculate Kp for the reaction.
2NO(g) + Br2(g)   2NOBr(g)

Accepted Answer

A)  7.45 × 10-3 
B)  0.109 
C)  9.18 
D)  91.8 
E)  134 
A)  7.45 × 10-3 
B)  0.109 
C)  9.18 
D)  91.8 
E)  134

Question 3

H2SO3(aq)   HSO3(aq) + H+(aq) Kc = 1.4 × 10-2 H2SO3(aq)   SO32-(aq) + 2H+(aq) Kc = 9.1 × 10-10
Given the above equilibrium constant data at 25°C, what is the value of Kc at this temperature for the reaction
HSO3-(aq)   SO32-(aq) + H+(aq)?

Accepted Answer

A)  6.5 ×10-8 
B)  1.3 × 10-11 
C)  7.8 × 1010 
D)  1.5 × 107 
E)  None of these choices are correct. 
A)  6.5 ×10-8 
B)  1.3 × 10-11 
C)  7.8 × 1010 
D)  1.5 × 107 
E)  None of these choices are correct.

Question 4

Consider the following two equilibria and their respective equilibrium constants: (1) NO(g) + ½O2(g)   NO2(g)
(2) 2NO2(g)   2NO(g) + O2(g)
Which one of the following is the correct relationship between the equilibrium constants K1 and K2?

Accepted Answer

A)  K2 = 2/K1 
B)  K2 = (1/K1)2 
C)  K2 = -K1/2 
D)  K2 = 1/(2K1) 
E)  K2 = 1/(2K1)2 
A)  K2 = 2/K1 
B)  K2 = (1/K1)2 
C)  K2 = -K1/2 
D)  K2 = 1/(2K1) 
E)  K2 = 1/(2K1)2

Question 5

A mixture of 0.500 mole of carbon monoxide and 0.400 mole of bromine was placed into a rigid 1.00-L container and the system was allowed to come to equilibrium. The equilibrium
Concentration of COBr2 was 0.233 M. What is the value of Kc for this reaction?
CO(g) + Br2(g)   COBr2(g)

Accepted Answer

A)  5.23 
B)  1.22 
C)  1.165 
D)  0.858 
E)  0.191 
A)  5.23 
B)  1.22 
C)  1.165 
D)  0.858 
E)  0.191

Question 6

A chemical reaction has an equilibrium constant of 2 × 106. If this reaction is at equilibrium, select the one correct conclusion that can be made about the reaction.

Accepted Answer

A)  The forward and back reactions have stopped. 
B)  The limiting reactant has been used up. 
C)  The forward and reverse rate constants are equal. 
D)  The forward and reverse reaction rates are equal. 
E)  None of these choices are correct. 
A)  The forward and back reactions have stopped. 
B)  The limiting reactant has been used up. 
C)  The forward and reverse rate constants are equal. 
D)  The forward and reverse reaction rates are equal. 
E)  None of these choices are correct.

Question 7

Which of the following has an effect on the magnitude of the equilibrium constant?

Accepted Answer

A)  removing products as they are formed 
B)  adding more of a reactant 
C)  adding a catalyst 
D)  increasing the pressure, in a gas-phase reaction 
E)  change in temperature 
A)  removing products as they are formed 
B)  adding more of a reactant 
C)  adding a catalyst 
D)  increasing the pressure, in a gas-phase reaction 
E)  change in temperature

Question 8

Write the mass-action expression,       
c, for the following chemical reaction equation.
2C6H6(g) + 15O2(g)   12CO2(g) + 6H2O(g)

Accepted Answer

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

Question 9

If all of the coefficients in the balanced equation for an equilibrium reaction are doubled, then the value of the equilibrium constant, Kc, will also be doubled.

Accepted Answer

A) True 
 B)False

Question 10

Sodium hydrogen carbonate decomposes above 110°C to form sodium carbonate, water, and carbon dioxide. 2NaHCO3(s)   Na2CO3(s) + H2O(g) + CO2(g)
One thousand grams of sodium hydrogen carbonate are added to a reaction vessel, the temperature is increased to 200°C, and the system comes to equilibrium. What happens in this system if another 50 g of sodium carbonate are now added?

Accepted Answer

A)  The partial pressure of carbon dioxide will increase. 
B)  The partial pressure of carbon dioxide will decrease. 
C)  The partial pressure of carbon dioxide will be unchanged. 
D)  The amounts of all products will be greater when equilibrium is reestablished. 
E)  None of these choices are correct. 
A)  The partial pressure of carbon dioxide will increase. 
B)  The partial pressure of carbon dioxide will decrease. 
C)  The partial pressure of carbon dioxide will be unchanged. 
D)  The amounts of all products will be greater when equilibrium is reestablished. 
E)  None of these choices are correct.

Question 11

What is the mass-action expression,   c, for the following chemical reaction? Cu2+(aq) + 4NH3(aq)   Cu(NH3)42+(aq)

Accepted Answer

A)    
B)    
C)    
D)    
E)  None of these choices are correct. 
A)    
B)    
C)    
D)    
E)  None of these choices are correct.

Question 12

Chemical reactions generally reach equilibrium because one of the reactants is used up.

Accepted Answer

A) True 
 B)False

Question 13

The following reaction is at equilibrium in a closed container. CuSO4.5H2O(s)   CuSO4(s) + 5H2O(g)
Which, if any, of the following actions will lead to an increase in the pressure of H2O present at equilibrium?

Accepted Answer

A)  increasing the volume of the container 
B)  decreasing the volume of the container 
C)  adding a catalyst 
D)  removing some solid CuSO4 
E)  None of these choices are correct. 
A)  increasing the volume of the container 
B)  decreasing the volume of the container 
C)  adding a catalyst 
D)  removing some solid CuSO4 
E)  None of these choices are correct.

Question 14

Ammonium iodide dissociates reversibly to ammonia and hydrogen iodide. NH4I(s)   NH3(g) + HI(g)
At 400°C, Kp = 0.215. Calculate the partial pressure of ammonia at equilibrium when a sufficient quantity of ammonium iodide is heated to 400°C.

Accepted Answer

A)  0.103 atm 
B)  0.215 atm 
C)  0.232 atm 
D)  0.464 atm 
E)  2.00 atm 
A)  0.103 atm 
B)  0.215 atm 
C)  0.232 atm 
D)  0.464 atm 
E)  2.00 atm

Question 15

Methanol can be synthesized by combining carbon monoxide and hydrogen. CO(g) + 2H2(g)   CH3OH(g)
A reaction vessel contains the three gases at equilibrium with a total pressure of 1.00 atm. What will happen to the partial pressure of hydrogen if enough argon is added to raise the total pressure to 1.4 atm?

Accepted Answer

A)  The partial pressure of hydrogen will decrease. 
B)  The partial pressure of hydrogen will increase. 
C)  The partial pressure of hydrogen will be unchanged. 
D)  Kp needs to be known before a prediction can be made. 
E)  Both Kp and the temperature need to be known before a prediction can be made. 
A)  The partial pressure of hydrogen will decrease. 
B)  The partial pressure of hydrogen will increase. 
C)  The partial pressure of hydrogen will be unchanged. 
D)  Kp needs to be known before a prediction can be made. 
E)  Both Kp and the temperature need to be known before a prediction can be made.

Question 16

The equilibrium constant for reaction (1) below is 276. Under the same conditions, what is the equilibrium constant of reaction (2)? (1) ½X2(g) + ½Y2(g)   XY(g)
(2) 2XY(g)   X2(g) + Y2(g)

Accepted Answer

A)  6.02 × 10-2 
B)  7.25 × 10-3 
C)  3.62 × 10-3 
D)  1.31 × 10-5 
E)  None of these choices are correct. 
A)  6.02 × 10-2 
B)  7.25 × 10-3 
C)  3.62 × 10-3 
D)  1.31 × 10-5 
E)  None of these choices are correct.

Question 17

10.0 mL of a 0.100 mol L-1 solution of a metal ion M2+ is mixed with 10.0 mL of a 0.100 mol L-1 solution of a substance L. The following equilibrium is established: M2+(aq) + 2L(aq)   ML22+(aq)
At equilibrium the concentration of L is found to be 0.0100 mol L-1. What is the equilibrium concentration of ML22+, in mol L-1?

Accepted Answer

A)  0.100 mol L-1 
B)  0.050 mol L-1 
C)  0.025 mol L-1 
D)  0.0200 mol L-1 
E)  0.0100 mol L-1 
A)  0.100 mol L-1 
B)  0.050 mol L-1 
C)  0.025 mol L-1 
D)  0.0200 mol L-1 
E)  0.0100 mol L-1

Question 18

Magnesium hydroxide is used in several antacid formulations. When it is added to water it dissociates into magnesium and hydroxide ions. Mg(OH)2(s)   Mg2+(aq) + 2OH-(aq)
The equilibrium constant at 25°C is 8.9 × 10-12. One hundred grams of magnesium hydroxide is added to 1.00 L of water and equilibrium is established. What happens to the solution if another 10 grams of Mg(OH)2 are now added to the mixture?

Accepted Answer

A)  The hydroxide ion concentration will decrease. 
B)  The hydroxide ion concentration will increase. 
C)  The hydroxide ion concentration will be unchanged. 
D)  The solution will become supersaturated. 
E)  None of these choices are correct. 
A)  The hydroxide ion concentration will decrease. 
B)  The hydroxide ion concentration will increase. 
C)  The hydroxide ion concentration will be unchanged. 
D)  The solution will become supersaturated. 
E)  None of these choices are correct.

Question 19

Increasing the initial amount of the limiting reactant in a reaction will increase the value of the equilibrium constant, Kc.

Accepted Answer

A) True 
 B)False

Question 20

The equilibrium constant for the reaction of bromine with chlorine to form bromine monochloride is 58.0 at a certain temperature. Br2(g) + Cl2(g)   2BrCl(g)
What is the equilibrium constant for the following reaction?
BrCl(g)   ½Br2(g) + ½Cl2(g)

Accepted Answer

A)  2.97 × 10-4 
B)  1.72 × 10-2 
C)  3.45 × 10-2 
D)  1.31 × 10-1 
E)  > 1.00 
A)  2.97 × 10-4 
B)  1.72 × 10-2 
C)  3.45 × 10-2 
D)  1.31 × 10-1 
E)  > 1.00

In a chemical reaction, if the starting concentrations of reactants are increased, then the equilibrium constant K_c will also increase.

Nitric oxide and bromine were allowed to react in a sealed container. When equilibrium was reached P_NO = 0.526 atm, = 1.59 atm, and P_NOBr = 7.68 atm. Calculate K_p for the reaction. 2NO(g) + Br₂(g) 2NOBr(g)

H₂SO₃(aq) HSO₃(aq) + H⁺(aq) K_c = 1.4 × 10^-2 H₂SO₃(aq) SO₃^2-(aq) + 2H⁺(aq) K_c = 9.1 × 10^-10 Given the above equilibrium constant data at 25°C, what is the value of K_c at this temperature for the reaction HSO₃^-(aq) SO₃^2-(aq) + H⁺(aq)?

Consider the following two equilibria and their respective equilibrium constants: (1) NO(g) + ½O2(g) NO2(g) (2) 2NO₂(g) 2NO(g) + O₂(g) Which one of the following is the correct relationship between the equilibrium constants K₁ and K₂?

A mixture of 0.500 mole of carbon monoxide and 0.400 mole of bromine was placed into a rigid 1.00-L container and the system was allowed to come to equilibrium. The equilibrium Concentration of COBr₂ was 0.233 M. What is the value of Kc for this reaction? CO(g) + Br₂(g) COBr₂(g)

A chemical reaction has an equilibrium constant of 2 × 10⁶. If this reaction is at equilibrium, select the one correct conclusion that can be made about the reaction.

Which of the following has an effect on the magnitude of the equilibrium constant?

Write the mass-action expression, _c, for the following chemical reaction equation. 2C₆H₆(g) + 15O₂(g) 12CO₂(g) + 6H₂O(g)

If all of the coefficients in the balanced equation for an equilibrium reaction are doubled, then the value of the equilibrium constant, K_c, will also be doubled.

What is the mass-action expression, c, for the following chemical reaction? Cu₂₊(aq) + 4NH₃(aq) Cu(NH₃)₄²⁺(aq)

Chemical reactions generally reach equilibrium because one of the reactants is used up.

The following reaction is at equilibrium in a closed container. CuSO₄.5H₂O(s) CuSO₄(s) + 5H₂O(g) Which, if any, of the following actions will lead to an increase in the pressure of H₂O present at equilibrium?

Ammonium iodide dissociates reversibly to ammonia and hydrogen iodide. NH₄I(s) NH₃(g) + HI(g) At 400°C, K_p = 0.215. Calculate the partial pressure of ammonia at equilibrium when a sufficient quantity of ammonium iodide is heated to 400°C.

The equilibrium constant for reaction (1) below is 276. Under the same conditions, what is the equilibrium constant of reaction (2)? (1) ½X₂(g) + ½Y₂(g) XY(g) (2) 2XY(g) X₂(g) + Y₂(g)

Increasing the initial amount of the limiting reactant in a reaction will increase the value of the equilibrium constant, K_c.

The equilibrium constant for the reaction of bromine with chlorine to form bromine monochloride is 58.0 at a certain temperature. Br₂(g) + Cl₂(g) 2BrCl(g) What is the equilibrium constant for the following reaction? BrCl(g) ½Br₂(g) + ½Cl₂(g)

Keys to Studying Chemistry Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces Liquids, Solids, and Phase Changes

The Properties of Mixtures Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics Rates and Mechanisms of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics Entropy, Free Energy, and Reaction Direction

Electrochemistry Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Exam 17: Equilibrium the Extent of Chemical Reactions

In a chemical reaction, if the starting concentrations of reactants are increased, then the equilibrium constant Kc will also increase.

Nitric oxide and bromine were allowed to react in a sealed container. When equilibrium was reached PNO = 0.526 atm, = 1.59 atm, and PNOBr = 7.68 atm. Calculate Kp for the reaction. 2NO(g) + Br2(g) 2NOBr(g)

H2SO3(aq) HSO3(aq) + H+(aq) Kc = 1.4 × 10-2 H2SO3(aq) SO32-(aq) + 2H+(aq) Kc = 9.1 × 10-10 Given the above equilibrium constant data at 25°C, what is the value of Kc at this temperature for the reaction HSO3-(aq) SO32-(aq) + H+(aq)?

Consider the following two equilibria and their respective equilibrium constants: (1) NO(g) + ½O2(g) NO2(g) (2) 2NO2(g) 2NO(g) + O2(g) Which one of the following is the correct relationship between the equilibrium constants K1 and K2?

A mixture of 0.500 mole of carbon monoxide and 0.400 mole of bromine was placed into a rigid 1.00-L container and the system was allowed to come to equilibrium. The equilibrium Concentration of COBr2 was 0.233 M. What is the value of Kc for this reaction? CO(g) + Br2(g) COBr2(g)

A chemical reaction has an equilibrium constant of 2 × 106. If this reaction is at equilibrium, select the one correct conclusion that can be made about the reaction.

Which of the following has an effect on the magnitude of the equilibrium constant?

Write the mass-action expression, c, for the following chemical reaction equation. 2C6H6(g) + 15O2(g) 12CO2(g) + 6H2O(g)

If all of the coefficients in the balanced equation for an equilibrium reaction are doubled, then the value of the equilibrium constant, Kc, will also be doubled.

What is the mass-action expression, c, for the following chemical reaction? Cu2+(aq) + 4NH3(aq) Cu(NH3)42+(aq)

Chemical reactions generally reach equilibrium because one of the reactants is used up.

The following reaction is at equilibrium in a closed container. CuSO4.5H2O(s) CuSO4(s) + 5H2O(g) Which, if any, of the following actions will lead to an increase in the pressure of H2O present at equilibrium?

Ammonium iodide dissociates reversibly to ammonia and hydrogen iodide. NH4I(s) NH3(g) + HI(g) At 400°C, Kp = 0.215. Calculate the partial pressure of ammonia at equilibrium when a sufficient quantity of ammonium iodide is heated to 400°C.

The equilibrium constant for reaction (1) below is 276. Under the same conditions, what is the equilibrium constant of reaction (2)? (1) ½X2(g) + ½Y2(g) XY(g) (2) 2XY(g) X2(g) + Y2(g)

Increasing the initial amount of the limiting reactant in a reaction will increase the value of the equilibrium constant, Kc.

The equilibrium constant for the reaction of bromine with chlorine to form bromine monochloride is 58.0 at a certain temperature. Br2(g) + Cl2(g) 2BrCl(g) What is the equilibrium constant for the following reaction? BrCl(g) ½Br2(g) + ½Cl2(g)

Keys to Studying Chemistry Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces Liquids, Solids, and Phase Changes

The Properties of Mixtures Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics Rates and Mechanisms of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics Entropy, Free Energy, and Reaction Direction

Electrochemistry Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

In a chemical reaction, if the starting concentrations of reactants are increased, then the equilibrium constant K_c will also increase.

Nitric oxide and bromine were allowed to react in a sealed container. When equilibrium was reached P_NO = 0.526 atm, = 1.59 atm, and P_NOBr = 7.68 atm. Calculate K_p for the reaction. 2NO(g) + Br₂(g) 2NOBr(g)

H₂SO₃(aq) HSO₃(aq) + H⁺(aq) K_c = 1.4 × 10^-2 H₂SO₃(aq) SO₃^2-(aq) + 2H⁺(aq) K_c = 9.1 × 10^-10 Given the above equilibrium constant data at 25°C, what is the value of K_c at this temperature for the reaction HSO₃^-(aq) SO₃^2-(aq) + H⁺(aq)?

Consider the following two equilibria and their respective equilibrium constants: (1) NO(g) + ½O2(g) NO2(g) (2) 2NO₂(g) 2NO(g) + O₂(g) Which one of the following is the correct relationship between the equilibrium constants K₁ and K₂?

A mixture of 0.500 mole of carbon monoxide and 0.400 mole of bromine was placed into a rigid 1.00-L container and the system was allowed to come to equilibrium. The equilibrium Concentration of COBr₂ was 0.233 M. What is the value of Kc for this reaction? CO(g) + Br₂(g) COBr₂(g)

A chemical reaction has an equilibrium constant of 2 × 10⁶. If this reaction is at equilibrium, select the one correct conclusion that can be made about the reaction.

Write the mass-action expression, _c, for the following chemical reaction equation. 2C₆H₆(g) + 15O₂(g) 12CO₂(g) + 6H₂O(g)

If all of the coefficients in the balanced equation for an equilibrium reaction are doubled, then the value of the equilibrium constant, K_c, will also be doubled.

What is the mass-action expression, c, for the following chemical reaction? Cu₂₊(aq) + 4NH₃(aq) Cu(NH₃)₄²⁺(aq)

The following reaction is at equilibrium in a closed container. CuSO₄.5H₂O(s) CuSO₄(s) + 5H₂O(g) Which, if any, of the following actions will lead to an increase in the pressure of H₂O present at equilibrium?

Ammonium iodide dissociates reversibly to ammonia and hydrogen iodide. NH₄I(s) NH₃(g) + HI(g) At 400°C, K_p = 0.215. Calculate the partial pressure of ammonia at equilibrium when a sufficient quantity of ammonium iodide is heated to 400°C.

The equilibrium constant for reaction (1) below is 276. Under the same conditions, what is the equilibrium constant of reaction (2)? (1) ½X₂(g) + ½Y₂(g) XY(g) (2) 2XY(g) X₂(g) + Y₂(g)

Increasing the initial amount of the limiting reactant in a reaction will increase the value of the equilibrium constant, K_c.

The equilibrium constant for the reaction of bromine with chlorine to form bromine monochloride is 58.0 at a certain temperature. Br₂(g) + Cl₂(g) 2BrCl(g) What is the equilibrium constant for the following reaction? BrCl(g) ½Br₂(g) + ½Cl₂(g)