Chemical Equilibrium Complete Test Bank Chapter 14

Chemistry: Molecular Nature of Matter, 8e (Jespersen)

Chapter 14 Chemical Equilibrium

1) A chemical system is considered to have reached dynamic equilibrium when

A) the frequency of collisions between the reactant molecules is equal to the frequency of collisions between the product molecules.

B) the sum of the concentrations of each of the reactant species is equal to the sum of the concentrations of each of the product species.

C) the activation energy of the forward reaction is equal to the activation energy of the reverse reaction.

D) the rate of production of each of the products is equal to the rate of their consumption by the reverse reaction.

E) the rate of production of each of the product species is equal to the rate of consumption of each of the reactant species.

Diff: 1

Section: 14.1

2) A chemical system is considered to have reached equilibrium when

A) the rate of consumption of each of the product species by the reverse reaction is equal to the rate of production of each of the reactant species by the reverse reaction.

B) the sum of the concentrations of each of the reactant species is equal to the sum of the concentrations of each of the product species.

C) the rate of production of each of the product species is equal to the rate of consumption of each of the product species by the reverse reaction.

D) the rate of production of each of the product species is equal to the rate of consumption of each of the reactant species by the reverse reaction.

E) the rate of production of each of the product species by the forward reaction is equal to the rate of production of each of the reactant species by the reverse reaction.

Diff: 1

Section: 14.1

3) Which statement about chemical equilibrium is not true?

A) At equilibrium, the reactant and the product concentrations show no further change with time.

B) Chemical equilibrium can only be attained by starting with reagents from the reactant side of the equation.

C) At equilibrium, the forward reaction rate equals the reverse reaction rate.

D) The same equilibrium state can be attained starting either from the reactant or product side of the equation.

E) At equilibrium, the reactant and product concentrations are constant.

Diff: 1

Section: 14.1

4) Which of these statements are true about chemical equilibrium in general?

A) At equilibrium, the rate constant of the forward reaction is equal to the rate of the reverse reaction.

B) At equilibrium, the rate of the forward reaction is equal to the rate of the reverse reaction.

C) Equilibrium is the result of the cessation of all chemical change.

D) There is only one set of equilibrium concentrations that equals the Kc value.

E) At equilibrium the sum of the concentration of products equals the total concentration of the reactants.

Diff: 1

Section: 14.1

5) In a study of the system, H2(g) + I2(g) 2 HI(g), at 699 K, several different reaction mixtures, described below, were prepared, placed in 5.00 liter containers, and allowed to attain equilibrium at 699 K. Despite having the different starting compositions shown, four of the five mixtures had the identical composition at equilibrium. Which one of the systems attained a different equilibrium composition than the others?

A) System 1: 0.100 moles of H2, 0.000 moles of I2 and 0.600 moles of HI

B) System 2: 0.175 moles of H2, 0.075 moles of I2 and 0.450 moles of HI

C) System 3: 0.400 moles of H2, 0.300 moles of I2 and 0.000 moles of HI

D) System 4: 0.150 moles of H2, 0.100 moles of I2 and 0.500 moles of HI

E) System 5: 0.300 moles of H2, 0.200 moles of I2 and 0.200 moles of HI

Diff: 2

Section: 14.1

6) Given the two reactions shown with their equilibrium constants,

PCl3(g) + Cl2(g) PCl5(g) K1

2 NO(g) + Cl2(g) 2 NOCl(g) K2

What is the equilibrium constant for the reaction,

PCl5(g) + 2 NO(g) PCl3(g) + 2 NOCl(g)

A) K1K2

B) K2/K1

C) K1/K2

D) (K1K2)−1

E) K2 − K1

Diff: 1

Section: 14.1

7) In a study of the system, Cl2(g) + Br2(g) 2 BrCl(g), at 350 K, several different reaction mixtures, described below, were prepared, placed in 5.00 liter containers, and allowed to attain equilibrium at 350 K. Despite having the different starting compositions shown, four of the five mixtures had the identical composition at equilibrium. Which one of the systems attained a different equilibrium composition than the others?

A) System 1: 0.100 moles of Cl2, 0.000 moles of Br2 and 0.600 moles of BrCl

B) System 2: 0.250 moles of Cl2, 0.150 moles of Br2 and 0.300 moles of BrCl

C) System 3: 0.400 moles of Cl2, 0.300 moles of Br2 and 0.000 moles of BrCl

D) System 4: 0.300 moles of Cl2, 0.250 moles of Br2 and 0.250 moles of BrCl

E) System 5: 0.350 moles of Cl2, 0.250 moles of Br2 and 0.100 moles of BrCl

Diff: 2

Section: 14.1

8) In a study of the system, N2O4(g) 2 NO2(g), at 585 K, several different reaction mixtures, described below, were prepared, placed in 5.00 liter containers, and allowed to attain equilibrium at 480 K. Despite having different starting compositions shown, four of the five mixtures had the identical composition at equilibrium. Which one of the systems attained a different equilibrium composition than the others?

A) System 1: 0.400 moles of N2O4 and 0.800 moles of NO2

B) System 2: 0.300 moles of N2O4 and 1.000 moles of NO2

C) System 3: 0.800 moles of N2O4 and 0.000 moles of NO2

D) System 4: 0.600 moles of N2O4 and 0.400 moles of NO2

E) System 5: 0.400 moles of N2O4 and 0.700 moles of NO2

Diff: 2

Section: 14.1

9) In a study of the system, Cl2(g) + 2 NO(g) 2 NOCl(g), at 425 K, several different reaction mixtures, described below, were prepared, placed in 5.00 liter containers, and allowed to attain equilibrium at 425 K. Despite having different starting compositions shown, four of the five mixtures had the identical composition at equilibrium. Which one of the systems attained a different equilibrium composition than the others?

A) System 1: 0.100 moles of Cl2, 0.000 moles of NO and 0.600 moles of NOCl

B) System 2: 0.250 moles of Cl2, 0.300 moles of NO and 0.300 moles of NOCl

C) System 3: 0.400 moles of Cl2, 0.600 moles of NO and 0.000 moles of NOCl

D) System 4: 0.300 moles of Cl2, 0.250 moles of NO and 0.250 moles of NOCl

E) System 5: 0.350 moles of Cl2, 0.500 moles of NO and 0.100 moles of NOCl

Diff: 2

Section: 14.1

10) Which of the following is the correct equilibrium law for the following reaction?

N2H4(g) + 6H2O2(g) 2(g) + 8H2O(g)

A) Kc =

B) Kc = [NO2]2[H2O]8[N2H4] [H2O2]6

C) Kc = [NO2] [H2O] [N2H4] [H2O2]

D) Kc =

E) Kc =

Diff: 1

Section: 14.2

11) Which of the following is the correct equilibrium law for the following reaction?

N2(g) + 3H2(g) 2NH3(g)

A) Kc =

B) Kc = [NH3]2[N2] [H2]3

C) Kc = [NH3] [N2] [H2]

D) Kc =

E) Kc =

Diff: 1

Section: 14.2

12) Given the two reactions shown with their equilibrium constants,

PCl3(g) + ½ O2(g) POCl3(g) K1

NO(g) + ½ O2(g) NO2(g) K2

What is the equilibrium constant for the reaction,

PCl3(g) + NO2(g) POCl3(g) + NO(g)

A) K1K2

B) K2/K1

C) K1/K2

D) (K1K2)−1

E) K2 − K1

Diff: 2

Section: 14.2

13) Consider the following reactions and their associated equilibrium constants:

A + 2B C K1

D + E C K2

For the reaction A + 2B D + E, having equilibrium constant Kc,

A) Kc = (K1)(K2)

B) Kc = K2/K1

C) Kc = K1/K2

D) Kc = K1 − K2

E) Kc = K1 + K2

Diff: 2

Section: 14.2

14) The equilibrium constant for the reaction, H2(g) + I2(g) 2 HI(g) is 54.9 at 699.0 K. What is the equilibrium constant for 4 HI(g) 2 H2(g) + 2 I2(g) under the same conditions?

A) 109.8

B) 0.00911

C) 0.000332

D) −109.8

E) 0.0182

Diff: 2

Section: 14.2

15) For a specific reaction, which statement can be made about the equilibrium constant?

A) It can change with temperature.

B) It may be changed by addition of a catalyst.

C) It increases if the concentration of one of the products is increased.

D) It increases if the concentration of one of the products is decreased.

E) It always remains the same.

Diff: 2

Section: 14.2

16) Using this data,

2 NO(g) + Cl2(g) 2 NOCl(g) Kc = 3.20 × 10−-3

2 NO2(g) 2 NO(g) + O2(g) Kc = 15.5

calculate a value for Kc for the reaction,

NOCl(g) + ½ O2(g) NO2(g) + ½ Cl2(g)

A) 2.06 × 10−4

B) 4.84 × 10−3

C) 0.223

D) 4.49

E) 20.2

Diff: 2

Section: 14.2

17) For the reaction, 2SO2(g) + O2(g) 2SO3(g), at 900.0 K the equilibrium constant, Kc, has a value of 13.0. Calculate the value of Kp at the same temperature.

A) 97.3 × 103

B) 0.176

C) 960

D) 0.00174

E) 0.077

Diff: 2

Section: 14.3

18) A student is preparing a study of the reaction, 2CO2(g) 2CO(g) + O2(g), for which at 827 °C. What is the value of Kp at that same temperature?

A) 2.90 × 10−1

B) 3.86 × 10−1

C) 1.78 × 103

D) 2.37 × 103

E) 2.40 × 105

Diff: 2

Section: 14.3

19) For which one of the following reactions is Kp equal to Kc?

A) 4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g)

B) C(s) + CO2(g) 2CO(g)

C) 6CO2(g) + 6H2O(l) C6H12O6(s) + 6O2(g)

D) CaCO3(s) CaO(s) + CO2(g)

E) H2O(g) + C(s) H2(g) + CO(g)

Diff: 2

Section: 14.3

20) For which one of the following reactions is Kp equal to Kc?

A) 3O2(g) 2O3(g)

B) 2NH3(g) 3H2(g) + N2(g)

C) CaCO3(s) CaO(s) + CO2(g)

D) NH4I(s) NH3(g) + HI(g)

E) SnO2(s) + 2H2(g) Sn(s) + 2H2O(g)

Diff: 2

Section: 14.3

21) The concentration of a pure solid or a pure liquid is left out of the expression for the

equilibrium constant because

A) solids and liquids drive the reaction in an undetermined fashion.

B) solids and liquids do not react.

C) their concentrations cannot be determined.

D) solids and liquids react too slowly.

E) their activity is constant and independent of the amount of solid or liquid present.

Diff: 2

Section: 14.3

22) Write the mass action expression for the following reaction:

4Cr(s) + 3CCl4(g) 4CrCl3(g) + 4C(s)

A) Kc =

B) Kc =

C) Kc =

D) Kc =

E) Kc = [CrCl3]4 + [CCl4]3

Diff: 1

Section: 14.4

23) The equilibrium law for the system, CaO(s) + CO2(g) CaCO3(s), is

A) Kc = [CO2].

B) Kc = [CaCO3]/([CaO] [CO2]).

C) Kc = 1/[CO2].

D) Kc = [CaCO3]/[CaO].

E) Kc = ([CaO] [CO2])/[CaCO3].

Diff: 2

Section: 14.4

24) For the chemical reaction,

N2(g) + 3H2(g) 2NH3(g),

Kc = 4.2 × 102 at some temperature that we call T1. 4.00 moles of NH3 were placed in a 50.0-liter container at T1 and allowed to come to equilibrium. Which situation below is true at equilibrium?

A) [NH3] = 3 × [H2]

B) [NH3] > [H2]

C) [H2] > [NH3]

D) [NH3] = [H2]

E) [N2] = [NH3]

Diff: 2

Section: 14.5

25) The equilibrium constant for the reaction, R2 D2 is 6.8 × 10−10. Which one of the following statements is true?

A) The equilibrium concentration of D2 is always greater than that of R2.

B) The equilibrium concentration of R2 is always greater than that of D2.

C) Adding more R2 will increase the value of the equilibrium constant.

D) Adding a catalyst will increase the equilibrium concentration of D2.

E) Adding a catalyst will increase the value of the equilibrium constant.

Diff: 2

Section: 14.5

26) The following reactions occur at 298 K. Arrange them in order of increasing tendency to proceed to completion (least completion → greatest completion).

1) H4C3O4 + H2O H3O+ + H3C3O4− Kc = 1.4 × 10−3

2) H4C2O2 + H2O ] H3O+ + H3C2O2− Kc = 1.8 × 10−5

3) H4C3O3 + H2O H3O+ + H3C3O3− Kc = 4.1 × 10−3

4) H8C3O3 + H2O H3O+ + H7C3O3− Kc = 7.1 × 10−15

A) 3 < 1 < 2 < 4

B) 4 < 2 < 1 < 3

C) 4 < 3 < 2 < 1

D) 4 < 2 < 3 < 1

E) 3 < 2 < 4 < 1

Diff: 2

Section: 14.5

27) The following reactions occur at 298 K. Arrange them in order of increasing tendency to proceed to completion (least completion → greatest completion).

1) CaCO3(s) CaO(s) + CO2(g) Kc = 1.9 × 10−23

2) C(s) + H2O(g) CO(g) + H2(g) Kc = 1.6 × 10−21

3) 2H2(g) + O2(g) H2O(g) Kc = 3.2 × 1081

4) N2O4(g)+ H2O 2NO2(g) Kc = 4.6 × 10−3

A) 1 < 2 < 4 < 3

B) 3 < 1 < 2 < 4

C) 3 < 4 < 2 < 1

D) 1 < 3 < 2 < 4

E) 4 < 1 < 2 < 3

Diff: 2

Section: 14.5

28) For a system, H2(g) + I2(g) 2 HI(g), Kc = 62.9 at 750 K. 2.80 moles of HI were placed in a 10.0-liter container, it was brought up to 750 K, and allowed to come to equilibrium. Which situation described below is true, at equilibrium?

A) [HI] = 2 × [H2]

B) [HI] = [H2]

C) [HI] < [H2]

D) [HI] > [H2]

E) [H2] > [I2]

Diff: 1

Section: 14.5

29) The following reactions have equilibrium values all measured at 500 K. Arrange them in order of increasing tendency to proceed to completion

(least completion → greatest completion).

1) 2NOCl 2NO + Cl2 Kp = 1.7 × 10-2

2) N2O4 2NO2 Kp = 1.5 × 103

3) 2SO3 2SO2 + O2 Kp = 1.3 × 10−5

4) 2NO2 2NO + O2 Kp = 5.9 × 10−5

A) 2 < 1 < 3 < 4

B) 4 < 3 < 1 < 2

C) 3 < 1 < 4 < 2

D) 3 < 4 < 1 < 2

E) 4 < 3 < 2 < 1

Diff: 1

Section: 14.5

30) For the reaction, 2SO2(g) + O2(g) 2SO3(g), at 450.0 K the equilibrium constant, Kc, has a value of 4.62. A system was charged to give these initial concentrations, [SO3] = 0.254 M, [O2] = 0.00855 M, [SO2] = 0.500 M. In which direction will it go?

Hint: Find the value for Q and then compare that value to the given value for Kc.

A) to the right or the left depending on the pressure

B) to the left

C) it will remain at the same concentrations

D) to the right

E) to the right or the left depending on the volume

Diff: 3

Section: 14.5

31) For the reaction, 2SO2(g) + O2(g) 2SO3(g), at 450.0 K the equilibrium constant, Kc, has a value of 4.62. A system was charged to give these initial concentrations: [SO3] = 0.500 M, [O2] = 0.00855 M, [SO2] = 0.254 M. In which direction will it go?

Hint: Find the value for Q and then compare that value to the given value for Kc

A) to the right

B) it will remain at the same concentrations

C) to the left

D) to the right or the left depending on the pressure

E) to the right or the left depending on the volume

Diff: 3

Section: 14.5

32) For the reaction, 2SO2(g) + O2(g) 2SO3(g), at 450.0 K the equilibrium constant, Kc, has a value of 4.62. A system was charged to give these initial concentrations: [SO3] = 0.0254 M, [O2] = 0.00855 M, [SO2] = 0.500 M. In which direction will it go?

Hint: Find the value for Q and then compare that value to the given value for Kc

A) to the right

B) to the left

C) to the right or the left depending on the pressure

D) it will remain at the same concentrations

E) to the right or the left depending on the volume

Diff: 3

Section: 14.5

33) Given the reaction, 2NO(g) + O2(g) 2NO2(g), for which the enthalpy of reaction is .

Which one of the following actions will cause an increase in the equilibrium concentration of NO(g) in a closed reaction chamber?

A) adding more O2(g) through an injection nozzle

B) increasing the temperature of the system

C) removing the NO2(g) from the system

D) increasing the pressure of the system while temperature is kept constant

E) adding a catalyst

Diff: 1

Section: 14.6

34) The reaction, 2 SO3(g) 2 SO2(g) + O2(g) is endothermic. Predict what will happen if the temperature is increased.

A) Kc remains the same.

B) Kc decreases.

C) The pressure decreases.

D) More SO3(g) is produced.

E) Kc increases.

Diff: 2

Section: 14.6

35) Consider the following system, which is at equilibrium,

CO(g) + 3H2(g) CH4(g) + H2O(g).

The result of removing some CH4(g) and H2O(g) from the system is that

A) more CH4(g) and H2O(g) are produced to replace that which is removed.

B) Kc decreases.

C) more CO(g) is produced.

D) more H2O(g) is consumed to restore the equilibrium.

E) more CH4(g) is consumed to restore the equilibrium.

Diff: 2

Section: 14.6

36) Consider the following system, which is at equilibrium,

3C(s) + 3H2(g) CH4(g) + C2H2(g)

The result of removing some CH4(g) and C2H2(g) from the system is that

A) no further change occurs.

B) Kc increases.

C) more C(s) is produced.

D) more C2H2(g) is consumed to restore the equilibrium.

E) more CH4(g) and C2H2(g) are produced to replace that which is removed.

Diff: 2

Section: 14.6

37) Consider the following system, which is at equilibrium,

3C(s) + 3H2(g) CH4(g) + C2H2(g)

The result of removing some C(s) from the system will be:

A) Kc increases.

B) more C(s) is produced.

C) no further change occurs.

D) more CH4(g) and C2H2(g) are produced to restore the equilibrium.

E) more C2H2(g) is consumed to restore the equilibrium.

Diff: 2

Section: 14.6

38) The system, 2H2O(g) + 2Cl2(g) 4HCl(g) + O2(g), has a value of 8.00 for Kp. Initially, the partial pressures of H2O(g) and Cl2(g) are set at 0.100 atm, while those of HCl(g) and O2(g) are set at 0.250 atm. Which statement below is true?

A) Qp > Kp and the reaction proceeds to the right to reach equilibrium.

B) Qp < Kp and the reaction proceeds to the left to reach equilibrium.

C) The reaction system is already at equilibrium.

D) Qp > Kp and the reaction proceeds to the left to reach equilibrium.

E) Qp < Kp and the reaction proceeds to the right to reach equilibrium.

Diff: 2

Section: 14.6

39) The system, H2(g) + X2(g) 2HX(g) has a value of 24.4 for Kc. A system being studied in a 3.00 liter reactor was charged with 0.150 moles of H2, 0.150 moles of X2, and 0.600 moles of HX. A catalyst was introduced using a remote unit. Which statement below describes the situation?

Hint: Be sure to find molarities of all reactants and products before calculating Q.

A) The reaction goes to the right, Q < K.

B) The reaction goes to the left, Q < K.

C) The reaction goes to the right, Q > K.

D) The reaction goes to the left, Q > K.

E) It is not possible to predict in which direction the system will travel as it reacts.

Diff: 3

Section: 14.6

40) A study of the system, 4NH3(g) + 7O2(g) 2N2O4(g) + 6H2O(g), was carried out. A system was prepared with [NH3] = [O2] = 3.60 M as the only components initially. At equilibrium, [N2O4] is 0.60 M. Calculate the equilibrium concentration of O2.

Hint: Organize your information using an ICE table, then use the equilibrium N2O4 concentration to find the concentration of O2.

A) 3.00 M

B) 2.40 M

C) 1.50 M

D) 2.10 M

E) 3.30 M

Diff: 3

Section: 14.7

41) A study of the system, 4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g), was carried out. A system

was prepared with [NH3] = [O2] = 5.60 M as the only components initially. At equilibrium, [NO] is 0.36 M. Calculate the equilibrium concentration of O2.

Hint: Organize your information using an ICE table, then use the equilibrium NO concentration to find the concentration of O2.

A) 6.05 M

B) 5.15 M

C) 5.24 M

D) 0.60 M

E) 5.51 M

Diff: 3

Section: 14.7

42) NH2CO2NH4(s) undergoes the following reaction at 450 K to produce a system that

reaches equilibrium:

NH2CO2NH4(s) 2NH3(g) + CO2(g)

The total pressure in the closed container under these conditions is found to be 0.843 atm. Calculate a value for the equilibrium constant, Kp.

Hint: Organize your information using an ICE table, then use Dalton's Law to find the equilibrium pressures of each product gas.

A) 0.00701

B) 0.0888

C) 0.222

D) 0.599

Diff: 3

Section: 14.7

43) For the reaction system, 2SO2(g) + O2(g) 2SO3(g), the equilibrium concentrations are:

SO3: 0.120 M SO2: 0.860 M O2: 0.330 M

Calculate the value of Kc for this reaction.

A) 1.31

B) 2.51

C) 0.423

D) 0.872

E) 0.0590

Diff: 2

Section: 14.7

44) For the reaction system, H2(g) + X2(g) 2HX(g), Kc = 24.4 at 300 K. A system made up from these components which is at equilibrium contains 0.150 moles of H2 and 0.600 moles of HX in a 3.00-liter container. Calculate the number of moles of X2(g) present at equilibrium.

Hint: Be sure to find molarities of all reactants and products before finding the equilibrium amount of X2.

A) 0.0984 mol

B) 0.164 mol

C) 0.0328 mol

D) 0.131 mol

E) 0.393 mol

Diff: 3

Section: 14.7

45) For the reaction system, H2(g) + X2(g) 2HX(g), Kc = 24.4 at 300 K. A system made up from these components that is at equilibrium contains 0.200 moles of X2 and 0.600 moles of HX(g) in a 4.00 liter container. Calculate the number of moles of H2(g) present at equilibrium.

Hint: Be sure to find molarities of all reactants and products before finding the equilibrium amount of H2.

A) 0.059 mol

B) 0.074 mol

C) 0.123 mol

D) 0.148 mol

E) 0.295 mol

Diff: 3

Section: 14.7

46) For the reaction system, 2SO2(g) + O2(g) 2SO3(g), Kc has a value of 4.62 at 450.0 K. A system, at equilibrium, was found to contain 0.360 moles of SO2 and 0.900 moles of O2 in a 3.00 liter container. Calculate the number of moles of SO3 gas at equilibrium.

Hint: Be sure to find molarities of all reactants and products before finding the equilibrium amount of SO3.

A) 0.166 M

B) 0.734 M

C) 0.539 M

D) 0.424 M

E) 0.141 M

Diff: 3

Section: 14.7

47) For the reaction system, 2SO2(g) + O2(g) 2SO3(g), Kc has a value of 4.62 at 450.0 K. A system, at equilibrium, was found to contain 0.440 moles of SO2 and 0.880 moles of O2 in a 4.00 liter container. Calculate the number of moles of SO3 gas at equilibrium.

Hint: Find molarities of all reactants and products before finding the equilibrium amount of SO3.

A) 0.443 M

B) 0.887 M

C) 0.0492 M

D) 0.111 M

E) 0.0123 M

Diff: 3

Section: 14.7

48) At 1500 °C the system, 2NO(g) ] N2(g) + O2(g), was allowed to come to equilibrium. The equilibrium concentrations were: NO(g) = 0.00035 M, N2(g) = 0.040 M, and O2(g) = 0.040 M. What is the value of Kc for the system at this temperature?

A) 3.3 × 104

B) 7.7 × 10−5

C) 2.2 × 10−1

D) 4.6

E) 1.3 × 104

Diff: 2

Section: 14.7

49) For the reaction system, 2SO2(g) + O2(g) 2SO3(g), Kc has a value of 4.62 at 450.0 K. A system, at equilibrium, has the following concentrations: [SO3] = 0.254 M, [O2] = 0.00855 M.

What is the equilibrium concentration of SO2(g)?

A) 1.28 M

B) 0.216 M

C) 0.465 M

D) 6.43 M

E) 41.3 M

Diff: 2

Section: 14.7

50) For the reaction, H2(g) + I2(g) 2HI(g), Kc = 54.9 at 699.0 K. A system, at equilibrium, contains 2.50 moles of HI(g) and 2.12 moles of I2(g) in a 5.00 liter vessel. How many moles of H2(g) should there be in the container?

Hint: Be sure to find molarities of all reactants and products before finding the equilibrium amount of H2.

A) 0.0537 moles

B) 0.380 moles

C) 0.0215 moles

D) 0.0107 moles

E) 2.12 moles

Diff: 3

Section: 14.7

51) The system, 2NO(g) N2(g) + O2(g) was allowed to come to equilibrium at 1500 °C. The equilibrium concentrations were: NO(g) = 0.00035 M, N2(g) = 0.040 M, and O2(g) = 0.040 M.

What is the value of Kp for the system at this temperature?

A) 2.2 × 10−1

B) 1.3 × 104

C) 3.3 × 103

D) 4.6

E) 1.5

Diff: 2

Section: 14.7

52) For the reaction, 2BrCl(g) Cl2(g) + Br2(g), Kp has a value of 0.140 at 350 K. In a container housing this system, the [Cl2(g)] = [Br2(g)] = 0.0200 M at equilibrium. What is the value of the partial pressure of BrCl(g)?

Hint: The ideal gas law is needed to convert molarity to pressure.

A) 2.86 × 10−3 atm

B) 5.35 × 10−2 atm

C) 8.21 × 10−2 atm

D) 1.25 × 10−5 atm

E) 1.54 atm

Diff: 3

Section: 14.7

53) A study of the system, 4NH3(g) + 7O2(g) 2N2O4(g) + 6H2O(g), was carried out. A system was prepared with [NH3] = [O2] = 3.60 M as the only components initially. At equilibrium, [N2O4] is 0.600 M. Calculate the equilibrium concentration of NH3(g).

Hint: Organize your information using an ICE table, then use the equilibrium N2O4 concentration to find the concentration of NH3.

A) 3.00 M

B) 2.10 M

C) 3.30 M

D) 1.80 M

E) 2.40 M

Diff: 3

Section: 14.7

54) A study of the system, 4NH3(g) + 7O2(g) 2N2O4(g) + 6H2O(g), was carried out. A system was prepared with [N2O4] = [H2O] = 3.60 M as the only components initially. At equilibrium, [H2O] is 0.600 M. Calculate the equilibrium concentration of NH3(g).

Hint: Organize your information using an ICE table, then use the equilibrium H2O concentration to find the concentration of NH3.

A) 1.50 M

B) 0.90 M

C) 3.00 M

D) 2.40 M

E) 2.00 M

Diff: 3

Section: 14.7

55) A study of the following system, 4 NH3(g) + 7 O2(g) 2 N2O4(g) + 6 H2O(g), was carried out. A system was prepared with [N2O4] = [H2O] = 3.60 M as the only components initially. At equilibrium, [H2O] is 0.600 M. Calculate the equilibrium concentration of O2(g).

Hint: Organize your information using an ICE table, then use the equilibrium H2O concentration to find the concentration of O2.

A) 0.700 M

B) 3.00 M

C) 1.00 M

D) 2.40 M

E) 3.50 M

Diff: 3

Section: 14.7

56) A vessel was filled with NOCl gas until the concentration was 0.398 mol/liter. The temperature of the system was increased to 245 °C and the system was allowed to undergo the reaction, , until equilibrium was attained. The physical chemistry students did a calculation and found the [Cl2] at that point was 0.0225 mol/liter. Calculate the value of Kc at that temperature.

A) 2.87 × 10−3

B) 3.66 × 10−4

C) 8.13 × 10−3

D) 1.29 × 10−4

E) 9.14 × 10−5

Diff: 2

Section: 14.7

57) A study of the system, 4 NH3(g) + 7 O2(g) 2 N2O4(g) + 6 H2O(g), was carried out. A system was prepared with [NH3] = [O2] = 3.60 M as the only components initially. At equilibrium, [N2O4] is 0.60 M. Calculate the value of the equilibrium constant, Kc, for the reaction.

Hint: Organize your information using an ICE table, then use the equilibrium N2O4 concentration to find the concentrations of all reactants and products to find Kc.

A) 8.1

B) 0.0000093

C) 0.30

D) 0.022

E) 3.3

Diff: 3

Section: 14.7

58) A study of the system, H2(g) + I2(g) 2HI(g), was carried out. Kc = 54.9 at 699.0 K for this reaction. A system was charged with 2.50 moles of HI in a 5.00-liter vessel as the only component initially. The system attained equilibrium at 699.0 K. How many moles of H2(g) should there be in the container at that time?

Hint: Be sure to find molarities of all reactants and products before plugging in to the equilibrium law and solving for the amount of H2.

A) 0.337 moles

B) 1.25 moles

C) 0.297 moles

D) 0.500 moles

E) 0.266 moles

Diff: 3

Section: 14.8

59) A study of the system, H2(g) + I2(g) 2HI(g), was carried out. Kc = 54.9 at 699.0 K for this reaction. A system was charged with 2.50 moles of H2(g) and 2.50 moles I2(g) in a 5.00 liter vessel as the only components initially. The system attained equilibrium at 699.0 K. How many moles of H2(g) should there be in the container at that time?

Hint: Be sure to find molarities of all reactants and products before plugging in to the equilibrium law and solving for the amount of H2.

A) 0.531 moles

B) 0.674 moles

C) 0.594 moles

D) 1.00 moles

E) 0.266 moles

Diff: 3

Section: 14.8

60) A student was assigned to carry out some calculations regarding the system described by the equation, I2(g) + Br2(g) 2IBr(g). Kc = 250 for this system. The system was to be charged with 0.0500 M of I2 and of Br2, then allowed to attain equilibrium at the desired temperature. What value should the student obtain for the equilibrium concentration of IBr(g)?

Hint: Organize your information using an ICE table, then use the equilibrium law to find the concentration of IBr.

A) 0.0056 M

B) 0.0444 M

C) 0.0888 M

D) 0.0950 M

E) 0.100 M

Diff: 3

Section: 14.8

61) For the system, H2(g) + I2(g) 2HI(g), Kc = 24.4 at 300 K. A system was charged with 2.00 moles of HI in a 3.00-liter container. The catalyst was introduced using a remote unit, and the system was allowed to come to equilibrium. How many moles of H2(g) will be present when the system reaches equilibrium?

Hint: Organize your information using an ICE table, then use the equilibrium expression to find the equilibrium amount of H2.

A) 0.288 moles

B) 0.337 moles

C) 0.388 moles

D) 0.404 moles

E) 0.424 moles

Diff: 3

Section: 14.8

62) For the system, H2(g) + I2(g) 2HI(g), Kc = 24.4 at 300 K. A system was charged with 1.00 moles of H2(g) and 1.00 moles of I2(g) in a 3.00 liter container. The catalyst was introduced using a remote unit, and the system was allowed to come to equilibrium. How many moles of H2(g) will be present when the system reaches equilibrium?

Hint: Organize your information using an ICE table, then use the equilibrium expression to find the equilibrium amount of H2.

A) 0.288 moles

B) 0.337 moles

C) 0.388 moles

D) 0.404 moles

E) 0.442 moles

Diff: 3

Section: 14.8

63) By convention, the ________ are always written on the left side of an equilibrium expression.

Diff: 1

Section: 14.1

64) When the direction of an equation is ________, the new equilibrium constant is the reciprocal of the original.

Diff: 1

Section: 14.2

65) For a given equilibrium process A + B C + D the value of Kc was found to be equal to

3.2 × 10−4. Therefore, the reaction favors ________.

Diff: 1

Section: 14.2

66) Write the equilibrium law for the reaction,

SO2Cl2(g) + 2NO(g) SO2(g) + 2NOCl(g)

Kc =

Diff: 1

Section: 14.2

67) The equilibrium law for a reaction in which all the components are gases is:

= Kc

Write the balanced equation for the reaction described by this equilibrium constant.

Diff: 1

Section: 14.2

68) Write the equilibrium law for the reaction,

2AsF3(g) + 3CCl4(g) 2AsCl3(g) + 3CCl2F2(g)

Kc =

Diff: 1

Section: 14.2

69) Write the equilibrium law, in terms of Kc, for the reaction,

N2H4(g) + 6H2O2(g) 2NO2(g) + 8H2O(g)

Kc =

Diff: 1

Section: 14.2

70) Write the equilibrium law, in terms of Kc, for the following chemical reaction:

Ni2+(aq) + 6NH3(aq) → [Ni(NH3)6]2+(aq)

Kc =

Diff: 1

Section: 14.2

71) Write the equilibrium law, in terms of Kp, for the reaction below.

CH4(g) + 2NO2(g) CO2(g) + 2H2O(g) + N2(g)

Kp =

Diff: 1

Section: 14.2

72) Write the expression for Kp, for the reaction,

N2(g) + O2(g) 2NO(g)

Kp =

Diff: 1

Section: 14.3

73) Write the expression for Kp, for the reaction,

CO(g) + 2H2(g) CH3OH(g)

Kp =

Diff: 1

Section: 14.3

74) Write the expression for Kp, for the reaction,

4HCl(g) + O2(g) 2H2O(g) + 2Cl2(g)

Kp =

Diff: 1

Section: 14.3

75) Write the expression for Kp, for the reaction,

SnCl2(s) + Cl2(g) SnCl4(g)

Kp =

Diff: 1

Section: 14.3

76) Write the expression for Kp, for the reaction,

NH4Cl(s) NH3(g) + HCl(g)

Diff: 1

Section: 14.3

77) Write the expression for Kc, for the reaction,

4Cr(s) + 3CCl4(g) 4CrCl3(g) + 4C(s)

Kc =

Diff: 1

Section: 14.4

78) Write the expression for Kc, for the reaction,

C(s) + H2O(g) HCHO(g)

Kc =

Diff: 1

Section: 14.4

79) Write the equilibrium law for the following chemical reaction:

TiO2(s) + C(s) + 2Cl2(g) → TiCl4(g) + CO2(g)

Kc =

Diff: 1

Section: 14.4

80) Write the equilibrium law for the following chemical reaction:

Ni(H2O)62+(aq) + 5NH3(aq) → Ni(NH3)5(H2O)2+(aq) + 5H2O(l)

Kc =

Diff: 1

Section: 14.4

81) Write the equilibrium law for the following chemical reaction:

2MnO4-(aq) + 5H2SO3(aq) 2Mn2+(aq) + 3H2O(l) + 5SO42-(aq) + 4H+(aq)

Kc =

Diff: 1

Section: 14.4

82) Write the equilibrium law for the following chemical reaction:

2Zn(s) + 4HCl(aq) 2ZnCl2(aq) + 2H2(g)

Kc =

Diff: 1

Section: 14.4

83) Write the equilibrium law for the following chemical reaction:

3NaOH(aq) + H3PO4(aq) Na3PO4(aq) + 3H2O(l)

Kc =

Diff: 1

Section: 14.4

84) The following reactions occur at 500 K. Arrange them in order of increasing tendency to proceed to completion (least → greatest tendency).

1. 2NOCl 2NO + Cl2 Kp = 1.7 × 10-2

2. 2SO3 2SO2 + O2 Kp = 1.3 × 10-5

3. 2NO2 2NO + O2 Kp = 5.9 × 10-5

Diff: 1

Section: 14.5

85) The following reactions occur at 500 K. Arrange them in order of increasing tendency to proceed to completion (least → greatest tendency).

1. H2(g) + Cl2(g) 2HCl(g) Kp = 4.0 × 1018

2. H2(g) + Br2(g) HBr(g) Kp = 1.3 × 1010

3. 2SO2(g) + O2(g) 2SO3(g) Kp = 2.5 × 1010

4. F2(g) 2F(g) Kp = 3.0 × 10-11

Diff: 1

Section: 14.5

86) For the reaction SO2Cl2(g) SO2(g) + Cl2(g) the addition of more chlorine gas will cause the reaction to shift to the ________.

Diff: 1

Section: 14.6

87) For the reaction SO2Cl2(g) SO2(g) + Cl2(g) the removal of sulfur dioxide gas will cause the reaction to shift to the ________.

Diff: 1

Section: 14.6

88) For the reaction SO2Cl2(g) SO2(g) + Cl2(g), if the container size was decreased while holding the temperature constant would cause the reaction to shift to the ________.

Diff: 1

Section: 14.6

89) For the reaction 3C(s) + 3 H2(g) CH4(g) + C2H2(g) addition of hydrogen gas would cause the reaction to shift to the ________.

Diff: 1

Section: 14.6

90) For the reaction 3C(s) + 3 H2(g) CH4(g) + C2H2(g) removal of CH4 would cause the reaction to shift to the ________.

Diff: 1

Section: 14.6

91) For the reaction 3C(s) + 3 H2(g) CH4(g) + C2H2(g) increasing the pressure would cause the reaction to shift to the ________.

Diff: 1

Section: 14.6

92) For the reaction 3C(s) + 3 H2(g) CH4(g) + C2H2(g) adding more C(s) to the system would cause ________.

Diff: 1

Section: 14.6

93) For the reaction A(g) + B(g) 2C(g) the equilibrium constant is 1.50 × 10−5. If the reaction starts in a closed container with initial concentrations of [A] = 0.500 M and [B] = 0.500 M, what will be the concentration of C at equilibrium?

Diff: 2

Section: 14.7

94) For the reaction 2SO2(g) + O2(g) 2SO3(g), the equilibrium concentrations are:

SO3: 0.130 M SO2: 0.875 M O2: 0.485 M

Calculate the value of Kc for this reaction.

Diff: 1

Section: 14.7

95) For the reaction 2COF2(g) CO2(g) + CF4(g), a system was prepared at a given temperature that had initial amounts of [COF2] = 0.510 M and [CO2] = 0.900 M only. When allowed to reach equilibrium [CF4] was found to be 0.100 M. Based upon this information the equilibrium constant Kc is ________.

Diff: 2

Section: 14.7

96) For the reaction PCl5(g) PCl3(g) + Cl2(g), Kc = 0.0128 at 250°C. A system was prepared with a starting concentration of 0.350 M. The system was then allowed to reach equilibrium. At equilibrium, the concentration of PCl3(g) would be ________.

Diff: 2

Section: 14.8

97) For the reaction PCl5(g) PCl3(g) + Cl2(g), Kc = 0.0128 at 250°C. A system was prepared with a starting concentrations of [PCl5] = 0.370 M, [PCl3] = 0.450 M and [Cl2] = 0.210 M. The system was then allowed to reach equilibrium. At equilibrium, the concentration of PCl3(g) would be ________.

Hint: Based on the value of Kc, the initial amount of products may decrease rather than increase.

Diff: 3

Section: 14.8

98) In a chemical reaction system that has reached equilibrium, the concentrations of the various species are constantly changing even though the total number of molecules is unchanging.

Diff: 1

Section: 14.1

99) In a chemical reaction system that has reached equilibrium, the concentration of each species is unchanging even though particular molecules continue to react throughout the system.

Diff: 1

Section: 14.1

100) When two chemical equilibria are added, we multiply their equilibrium constant values to

obtain the equilibrium constant for the overall reaction.

Diff: 1

Section: 14.1

101) When we reverse the direction of a chemical equation, you must now use the inverse of the equilibrium constant.

Diff: 1

Section: 14.2

102) When we multiply a chemical equation by a factor, the equilibrium constant is raised to the root of that factor.

Diff: 1

Section: 14.2

103) Why don't the concentrations of pure solids and liquids appear in the equilibrium laws of chemical reactions?

Diff: 2

Section: 14.4

104) Using Le Châtelier's Principle, describe how we could maximize the amount of ammonia produced in the Haber-Bosch process, by the reaction:

N2(g) + 3H2(g) 2NH3(g)

Diff: 2

Section: 14.4

105) The bicarbonate buffer system (shown below) helps to maintain a relatively constant blood pH and participates in transporting carbon dioxide to the lungs. The kidneys can remove HCO3-(aq) from the blood if needed to maintain homeostasis (a relatively constant internal environment). Based on Le Châtelier's Principle, what would increase in response to this increased excretion of HCO3-(aq) by the kidneys?

CO2(g) + H2O(l) H2CO3(aq) HCO3-(aq) + H+(aq)

Diff: 2

Section: 14.6

106) A vessel was filled with NOCl gas until the concentration was 0.398 mol L−1. The temperature of the system was increased to 245 °C and the system was allowed to undergo the reaction, 2NOCl(g) 2NO(g) + Cl2(g), until equilibrium was attained. The physical chemistry students did a calculation and found that the [Cl2] at that point was 0.0225 mol L−1. Calculate the value of Kp at that temperature.

A) 1.22 × 10−2

B) 1.55 × 10−2

C) 1.45 × 10−3

D) 4.46 × 10−3

E) 6.61 × 10−1

Diff: 2

Section: 14.6

107) A student was studying the reaction, PCl5(g) PCl3(g) + Cl2(g). At some temperature, T, the value of Kp for the system is 0.550. A system was created by placing a certain quantity of PCl5 into a closed reactor, then sealing it off and allowing the system to come to equilibrium. If the total pressure in the closed system was measured as 3.25 atm, what is the partial pressure of the Cl2(g) in the equilibrated system?

Hint: You will need to set up a system of two equations and two unknowns.

Diff: 3

Section: 14.7

108) A student was studying the reaction, SO2Cl2(g) SO2(g) + Cl2(g). The value of Kp for the system is 12.5 when the temperature is 565 K. A reactor vessel was charged with enough SO2Cl2(g) to give it a pressure of 1.200 atm at 25.0 °C. The sealed system was left undisturbed at 565 K so it could come to equilibrium. Calculate the partial pressure of the chlorine and the sulfur dioxide in atmospheres, at equilibrium.

Hint: The temperatures when the gas is introduced and when the system comes to equilibrium are different.

Diff: 3

Section: 14.8

109) A student was studying the reaction, SO2Cl2(g) SO2(g) + Cl2(g). The value of Kp for the system is 12.5 when the temperature is 565 K. A reactor vessel was charged with enough SO2Cl2(g) to give it a pressure of 1.200 atm at 25.0 °C. The sealed system was left undisturbed at 565 K so it could come to equilibrium. Calculate what the total pressure should be, in atmospheres, at equilibrium.

Hint: The temperatures when the gas is introduced and when the system comes to equilibrium are different.

Diff: 3

Section: 14.8

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