Deck 15: Chemical Equilibrium

Question 1

In what year was Fritz Haber awarded the Nobel Prize in chemistry for his development of a process for synthesizing ammonia directly from nitrogen and hydrogen?

A)1954
B)1933
C)1918
D)1900
E)1912

Answer 1

1918

Question 2

The equilibrium expression for K_p for the reaction below is ________. N₂ (g) + O₂ (g) 2NO (g)

A)
B)
C)
D)
E)none of the above

Answer 2

none of the above

Question 3

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? CO₂ (s) + H₂O (l) H⁺ (aq) + HCO₃^- (aq)

A)[H⁺][HCO₃^-] / [CO₂]
B)[CO₂] / [H⁺][HCO₃^-]
C)[H⁺][HCO₃^-] / [CO₂][H₂O]
D)[CO₂][H₂O] / [H⁺][HCO₃^-]
E)[H⁺][HCO₃^-]

Answer 3

[H⁺][HCO₃^-]

Question 4

Which one of the following is true concerning the Haber process?

A)It is a process used for shifting equilibrium positions to the right for more economical chemical synthesis of a variety of substances.
B)It is a process used for the synthesis of ammonia.
C)It is another way of stating Le Châtelier's principle.
D)It is an industrial synthesis of sodium chloride that was discovered by Karl Haber.
E)It is a process for the synthesis of elemental chlorine.

Question 5

What role did Karl Bosch play in development of the Haber-Bosch process?

A)He discovered the reaction conditions necessary for formation of ammonia.
B)He originally isolated ammonia from camel dung and found a method for purifying it.
C)Haber was working in his lab with his instructor at the time he worked out the process.
D)He developed the equipment necessary for industrial production of ammonia.
E)He was the German industrialist who financed the research done by Haber.

Question 6

Which one of the following will change the value of an equilibrium constant?

A)changing temperature
B)adding other substances that do not react with any of the species involved in the equilibrium
C)varying the initial concentrations of reactants
D)varying the initial concentrations of products
E)changing the volume of the reaction vessel

Question 7

The K_eq for the equilibrium below is 7.52 × 10^-2 at 480.0 °C. 2Cl₂ (g) + 2H₂O (g) 4HCl (g) + O₂ (g)
What is the value of K_eq at this temperature for the following reaction?
2HCl (g) + O₂ (g) Cl₂ (g) + H₂O (g)

A)13.3
B)3.65
C)-0.0376
D)5.66 × 10^-3
E)0.274

Question 8

The K_eq for the equilibrium below is 0.112 at 700.0 °C. SO₂ (g) + O₂ (g) SO₃ (g)
What is the value of K_eq at this temperature for the following reaction?
2SO₃ (g) 2SO₂ (g) + O₂ (g)

A)79.7
B)2.99
C)17.86
D)4.46
E)8.93

Question 9

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? HF (aq)+ H₂O (l) H₃O⁺ (aq)+ F^- (aq)

A)[HF][H₂O] / [H₃O⁺][F^-]
B)1 / [HF]
C)[H₃O⁺][F^-] / [HF][H₂O]
D)[H₃O⁺][F^-] / [HF]
E)[F^-] / [HF]

Question 10

The equilibrium expression for K_p for the reaction below is ________. 2O₃ (g) 3O₂ (g)

A)
B)
C)
D)
E)

Question 11

The equilibrium constant for reaction 1 is K. The equilibrium constant for reaction 2 is ________. (1) SO₂ (g) + (1/2)O₂ (g) SO₃ (g)
(2) 2SO₃ (g) 2SO₂ (g) + O₂ (g)

A)K²
B)2K
C)1/2K
D)1/K²
E)-K²

Question 12

Which of the following expressions is the correct equilibrium-constant expression for the following reaction? CO₂ (g)+ 2H₂ (g) CH₃OH (g)

A)
B)
C)
D)
E)

Question 13

The K_eq for the equilibrium below is 5.4 × 10¹³ at 480.0 °C. 2NO (g) + O₂ (g) 2NO₂ (g)
What is the value of K_eq at this temperature for the following reaction?
NO₂ (g) NO (g) + O₂ (g)

A)5.4 × 10^-13
B)5.4 × 10¹³
C)1.4 × 10^-7
D)5.66 × 10^-3
E)none of the above

Question 14

The K_eq for the equilibrium below is 0.112 at 700.0 °C. SO₂ (g) + O₂ (g) SO₃ (g)
What is the value of K_eq at this temperature for the following reaction?
SO₃ (g) SO₂ (g) + O₂ (g)

A)0.224
B)0.0125
C)0.112
D)8.93
E)-0.112

Question 15

The equilibrium-constant expression depends on the ________ of the reaction.

A)stoichiometry
B)mechanism
C)stoichiometry and mechanism
D)the quantities of reactants and products initially present
E)temperature

Question 16

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? 2SO₂ (g)+ O₂ (g) 2SO₃ (g)

A)[SO₃] / [SO₂][O₂]
B)[SO₂] / [SO₃]
C)[SO₃]² / [SO₂]²[O₂]
D)[SO₃]² / [SO₂]²[O₂]²
E)[SO₃] / [SO₂][O₂]²

Question 17

Which of the following expressions is the correct equilibrium-constant expression for the equilibrium between dinitrogen tetroxide and nitrogen dioxide? N₂O₄ (g) 2NO₂ (g)

A)
B)
C)
D)[NO₂][N₂O₄]
E)[NO₂]²[N₂O₄]

Question 18

Which of the following expressions is the correct equilibrium-constant expression for the reaction below? (NH₄)₂Se (s) 2NH₃ (g) + H₂Se (g)

A)[NH₃][H₂Se] / [(NH₄)₂Se]
B)[(NH₄)₂Se] / [NH₃]²[H₂Se]
C)1 / [(NH₄)₂Se]
D)[NH₃]²[H₂Se]
E)[NH₃]²[H₂Se] / [(NH₄)₂Se]

Question 19

Given the following reaction at equilibrium, if K_c = 1.90 × 10¹⁹ at 25.0 °C, K_p = ________. H₂ (g) + Br₂ (g) 2 HBr (g)

A)5.26 × 10^-20
B)1.56 × 10⁴
C)6.44 × 10⁵
D)1.90 × 10¹⁹
E)none of the above

Question 20

At equilibrium, ________.

A)all chemical reactions have ceased
B)the rates of the forward and reverse reactions are equal
C)the rate constants of the forward and reverse reactions are equal
D)the value of the equilibrium constant is 1
E)the limiting reagent has been consumed

Question 21

In which of the following reactions would increasing pressure at constant temperature not change the concentrations of reactants and products, based on Le Châtelier's principle?

A)N₂ (g) + 3H₂ (g) 2NH₃ (g)
B)N₂O₄ (g) 2NO₂ (g)
C)N₂ (g) + 2O₂ (g) 2NO₂ (g)
D)2N₂ (g) + O₂ (g) 2N₂O (g)
E)N₂ (g) + O₂ (g) 2NO (g)

Question 22

How is the reaction quotient used to determine whether a system is at equilibrium?

A)The reaction quotient must be satisfied for equilibrium to be achieved.
B)At equilibrium, the reaction quotient is undefined.
C)The reaction is at equilibrium when Q < K_eq.
D)The reaction is at equilibrium when Q > K_eq.
E)The reaction is at equilibrium when Q = K_eq.

Question 23

The equilibrium constant for the gas phase reaction N₂ (g) + 3H₂ (g) 2NH₃ (g)
Is K_eq = 4.34 × 10^-3 at 300 °C. At equilibrium, ________.

A)products predominate
B)reactants predominate
C)roughly equal amounts of products and reactants are present
D)only products are present
E)only reactants are present

Question 24

Of the following equilibria, only ________ will shift to the left in response to a decrease in volume.

A)H₂ (g) + Cl₂ (g) 2 HCl (g)
B)2 SO₃ (g) 2 SO₂ (g) + O₂ (g)
C)N₂ (g) + 3H₂ (g) 2 NH₃ (g)
D)4 Fe (s) + 3 O₂ (g) 2 Fe₂O₃ (s)
E)2HI (g) H₂ (g) + I₂ (g)

Question 25

Consider the following reaction at equilibrium: 2NH₃ (g) N₂ (g) + 3H₂ (g)
Le Châtelier's principle predicts that the moles of H₂ in the reaction container will increase with ________.

A)some removal of NH₃ from the reaction vessel (V and T constant)
B)a decrease in the total pressure (T constant)
C)addition of some N₂ to the reaction vessel (V and T constant)
D)a decrease in the total volume of the reaction vessel (T constant)
E)an increase in total pressure by the addition of helium gas (V and T constant)

Question 26

The equilibrium constant for the gas phase reaction N₂ (g) + O₂ (g) 2NO (g)
Is K_eq = 4.20 × 10^-31 at 30 °C. At equilibrium, ________.

A)products predominate
B)reactants predominate
C)roughly equal amounts of products and reactants are present
D)only products are present
E)only reactants are present

Question 27

The value of K_eq for the equilibrium H₂ (g) + I₂ (g) 2HI (g)
Is 794 at 25 °C. What is the value of K_eq for the equilibrium below? H₂ (g) + I₂ (g) HI (g)

A)397
B)0.035
C)28
D)1588
E)0.0013

Question 28

Of the following equilibria, only ________ will shift to the right in response to a decrease in volume.

A)H₂ (g) + Cl₂ (g) 2 HCl (g)
B)2 SO₃ (g) 2 SO₂ (g) + O₂ (g)
C)N₂ (g) + 3H₂ (g) 2NH₃ (g)
D)2 Fe₂O₃ (s) 4 Fe (s) + 3O₂ (g)
E)2HI (g) H₂ (g) + I₂ (g)

Question 29

The expression for K_p for the reaction below is ________. 4CuO (s) + CH₄ (g) CO₂ (g) + 4Cu (s) + 2H₂O (g)

A)
B)
C)
D)
E)

Question 30

Consider the following reaction at equilibrium: 2CO₂ (g) 2CO (g) + O₂ (g)ΔH° = -514 kJ
Le Châtelier's principle predicts that an increase in temperature will ________.

A)increase the partial pressure of O₂ (g)
B)decrease the partial pressure of CO₂ (g)
C)decrease the value of the equilibrium constant
D)increase the value of the equilibrium constant
E)increase the partial pressure of CO

Question 31

Which of the following statements is true?

A)Q does not change with temperature.
B)K_eq does not change with temperature, whereas Q is temperature dependent.
C)K does not depend on the concentrations or partial pressures of reaction components.
D)Q does not depend on the concentrations or partial pressures of reaction components.
E)Q is the same as K_eq when a reaction is at equilibrium.

Question 32

The effect of a catalyst on an equilibrium is to ________.

A)increase the rate of the forward reaction only
B)increase the equilibrium constant so that products are favored
C)slow the reverse reaction only
D)increase the rate at which equilibrium is achieved without changing the composition of the equilibrium mixture
E)shift the equilibrium to the right

Question 33

Consider the following reaction at equilibrium. 2CO₂ (g) 2CO (g) + O₂ (g)ΔH° = -514 kJ
Le Châtelier's principle predicts that the equilibrium partial pressure of CO (g)can be maximized by carrying out the reaction ________.

A)at high temperature and high pressure
B)at high temperature and low pressure
C)at low temperature and low pressure
D)at low temperature and high pressure
E)in the presence of solid carbon

Question 34

At 400 K, the equilibrium constant for the reaction Br₂ (g) + Cl₂ (g) 2BrCl (g)
Is K_p = 7.0. A closed vessel at 400 K is charged with 1.00 atm of Br₂ (g), 1.00 atm of Cl₂ (g), and 2.00 atm of BrCl (g). Use Q to determine which of the statements below is true.

A)The equilibrium partial pressures of Br₂, Cl₂, and BrCl will be the same as the initial values.
B)The equilibrium partial pressure of Br₂ will be greater than 1.00 atm.
C)At equilibrium, the total pressure in the vessel will be less than the initial total pressure.
D)The equilibrium partial pressure of BrCl (g)will be greater than 2.00 atm.
E)The reaction will go to completion since there are equal amounts of Br₂ and Cl₂.

Question 35

The value of K_eq for the equilibrium H₂ (g) + I₂ (g) 2HI (g)
Is 794 at 25 °C. At this temperature, what is the value of K_eq for the equilibrium below?
HI (g) H₂ (g) + I₂ (g)

A)1588
B)28
C)397
D)0.035
E)0.0013

Question 36

In which of the following reactions would increasing pressure at constant temperature change the concentrations of reactants and products, based on Le Châteliers principle?

A)N₂ (g) + 3H₂ (g) 2NH₃ (g)
B)N₂O₄ (g) 2NO₂ (g)
C)N₂ (g) + 2O₂ (g) 2NO₂ (g)
D)2N₂ (g) + O₂ (g) 2N₂O (g)
E)all of the above

Question 37

The equilibrium constant for the gas phase reaction 2SO₂ (g) + O₂ (g) 2SO₃ (g)
Is K_eq = 2.80 × 10² at 999 K. At equilibrium, ________.

A)products predominate
B)reactants predominate
C)roughly equal amounts of products and reactants are present
D)only products are present
E)only reactants are present

Question 38

The equilibrium-constant expression for the reaction Ti (s) + 2Cl₂ (g) TiCl₄ (l)
Is given by

A)
B)
C)
D)[Cl₂ (g)]^-2
E)

Question 39

The equilibrium constant for the gas phase reaction 2NH₃ (g) N₂ (g) + 3H₂ (g)
Is K_eq = 230 at 300 °C. At equilibrium, ________.

A)products predominate
B)reactants predominate
C)roughly equal amounts of products and reactants are present
D)only products are present
E)only reactants are present

Question 40

Consider the following equilibrium. 2 SO₂ (g) + O₂ (g) 2 SO₃ (g)
The equilibrium cannot be established when ________ is/are placed in a 1.0-L container.

A)0.25 mol SO₂ (g)and 0.25 mol O₂ (g)
B)0.75 mol SO₂ (g)
C)0.25 mol of SO₂ (g)and 0.25 mol of SO₃ (g)
D)0.50 mol O₂ (g)and 0.50 mol SO₃ (g)
E)1.0 mol SO₃ (g)

Question 41

Dinitrogentetraoxide partially decomposes according to the following equilibrium: N₂O₄ (g) 2 NO₂ (g)
A 1.00-L flask is charged with ofN₂O₄. At equilibrium at 373 K, 0.0055 mol of N₂O₄ remains. K_eq for this reaction is ________.

A)2.2 × 10^-4
B)13
C)0.22
D)0.022
E)0.87

Question 42

Which of the following expressions is the correct equilibrium-constant expression for the equilibrium between dinitrogen tetroxide and nitrogen dioxide? 5N₂O4(g) 10NO₂ (g)

A)[NO₂]¹⁰/[N₂O₄]⁵
B)[N₂O₄]¹⁰/[NO₂]⁵
C)[NO₂]⁵/[N₂O₄]¹⁰
D)[NO₂]⁵/[N₂O₄]⁵
E)[N₂O₄]⁵/[NO₂]⁵

Question 43

The equilibrium constant (K_p)for the interconversion of PCl₅ and PCl₃ is 0.0121: PCl₅ (g) PCl₃ (g) + Cl₂ (g)
A vessel is charged with PCl₅ giving an initial pressure of 0.123 atm. At equilibrium, the partial pressure of PCl₃ is ________ atm.

A)0.0782
B)0.0455
C)0.0908
D)0.0330
E)0.123

Question 44

Given the following reaction: CO (g) + 2 H₂(g) CH₃OH (g)
In an experiment, 0.42 mol of CO and 0.42 mol of H₂ were placed in a 1.00-L reaction vessel. At equilibrium, there were 0.29 mol of CO remaining. K_eq at the temperature of the experiment is ________.

A)2.80
B)0.357
C)14.5
D)17.5
E)none of the above

Question 45

A sealed 1.0 L flask is charged with 0.500 mol of I₂ and 0.500 mol of Br₂. An equilibrium reaction ensues: I₂ (g) + Br₂ (g) 2IBr (g)
When the container contents achieve equilibrium, the flask contains 0.84 mol of IBr. The value of K_eq is ________.

A)11
B)4.0
C)110
D)6.1
E)2.8

Question 46

The K_eq for the equilibrium below is 0.112 at 700.0 °C. SO₂ (g) + O₂ (g) SO₃ (g)
What is the value of K_eq at this temperature for the following reaction?
2SO₂ (g) + O₂ (g) 2SO₃ (g)

A)1.25 × 10^-2
B)2.24 × 10^-1
C)7.97 × 10¹
D)4.46
E)0.112

Question 47

Given the following reaction at equilibrium at 300.0 K: NH₄HS (s) NH₃ (g) + H₂S (g)
If pNH₃ = pH₂S = 0.105 atm, K_p = ________.

A).0110
B)4.99 × 10^-4
C).105
D).0821
E)5.66 × 10^-3

Question 48

At 200 °C, the equilibrium constant (K_p)for the reaction below is 2.40 × 10³. 2NO (g) N₂ (g) + O₂ (g)
A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O₂ is ________ atm.

A)294
B)35.7
C)17.9
D)6.00
E)1.50 × 10^-2

Question 49

The value of K_eq for the equilibrium CO₂ (g) + 2H₂ (g) CH₃OH (g)
Is 14.5 at 483 °C. What is the value of K_eq for the equilibrium below? CO₂ + H₂ (g) CH₃OH (g)

A)7.30
B)7.35
C)0.136
D)3.81
E)6.90 × 10^-2

Question 50

The K_eq for the equilibrium below is 7.52 × 10^-2 at 480.0 °C. 2Cl₂ (g) + 2H₂O (g) 4HCl (g) + O₂ (g)
What is the value of K_eq at this temperature for the following reaction?
8HCl (g) + 2O₂ (g) 4Cl₂ (g) + 4H₂O (g)

A)1.77 × 10²
B)5.66 × 10^-3
C)1.50 × 10^-1
D)-7.52 × 10^-2
E)7.52 × 10^-2

Question 51

A reaction vessel is charged with hydrogen iodide, which partially decomposes to molecular hydrogen and iodine: 2HI (g) H₂(g) + I₂(g)
When the system comes to equilibrium at 425 °C, P_HI = 0.708 atm, and P_H2 = P_I2 = 0.0960 atm. The value of K_p at this temperature is ________.

A)6.80 × 10^-2
B)1.30 × 10^-2
C)54.3
D)1.84 × 10^-2
E)K_p cannot be calculated for this gas reaction when the volume of the reaction vessel is not given.

Question 52

The value of K_eq for the following reaction is 0.25: SO₂ (g) + NO₂ (g) SO₃ (g) + NO (g)
The value of K_eq at the same temperature for the reaction below is ________.
3SO₂ (g) + 3NO₂ (g) 3SO₃ (g) + 3NO (g)

A)1.6 × 10^-2
B)7.5 × 10^-1
C)8.3 × 10^-2
D)6.4 × 10¹
E)0.25

Question 53

Acetic acid is a weak acid that dissociates into the acetate ion and a proton in aqueous solution: HC₂H₃O₂ (aq) C₂H₃O₂^- (aq) + H⁺ (aq)
At equilibrium at 25 °C a 0.100 M solution of acetic acid has the following concentrations:
[HC₂H₃O₂] = 0.0990 M, [C₂H₃O₂^-] = 1.33 × 10^-3 M and [H+] = 1.33 × 10^-3 M. The equilibrium constant, K_eq, for the ionization of acetic acid at 25 °C is ________.

A)5.71 × 10⁴
B)0.100
C)1.75 × 10^-7
D)1.79 × 10^-5
E)5.71 × 10⁶

Question 54

Given the following reaction at equilibrium, if K_c = 5.84 x 10⁵ at 230.0 °C, K_p = ________. 2NO (g) + O₂ (g) 2NO₂ (g)

A)3.67 × 10^-2
B)1.41 × 10⁴
C)6.44 × 10⁵
D)2.40 × 10⁶
E)2.41 × 10⁷

Question 55

The value of K_eq for the equilibrium H₂ (g) + I₂ (g) 2HI (g)
Is 54.0 at 427 °C. What is the value of K_eq for the equilibrium below?
HI (g) H₂ (g) + I₂(g)

A)27
B)7.35
C)0.136
D)2.92 × 10³
E)3.43 × 10^-4

Question 56

Given the following reaction at equilibrium at 450.0 °C: CaCO₃ (s) CaO (s) + CO₂ (g)
If pCO₂ = 0.0155 atm, K_c = ________.

A)155
B)0.0821
C)0.920
D)2.61 × 10^-4
E)9.20

Question 57

Given the following reaction at equilibrium, if K_p = 1.10 at 250.0 °C, K_c = ________. PCl₅ (g) PCl₃ (g) + Cl₂ (g)

A)3.90 × 10^-6
B)2.56 × 10^-2
C)1.10
D)42.9
E)47.2

Question 58

Consider the following chemical reaction: CO (g) + 2H₂(g) CH₃OH(g)
At equilibrium in a particular experiment, the concentrations of CO and H₂ were 0.15 M and 0.36, M respectively. What is the equilibrium concentration of CH₃OH? The value of K_eq for this reaction is 14.5 at the temperature of the experiment.

A)14.5
B)7.61 × 10^-3
C)2.82 × 10^-1
D)3.72 × 10^-3
E)1.34 × 10^-3

Question 59

The K_eq for the equilibrium below is 5.4 × 10¹³ at 480.0 °C. 2NO (g) + O₂ (g) 2NO₂ (g)
What is the value of K_eq at this temperature for the following reaction?
4NO (g) + 2O₂ (g) 4NO₂ (g)

A)2.9 × 10²⁷
B)8.5 × 10⁵⁴
C)3.4 × 10^-28
D)-1.1 × 10¹⁴
E)5.4 × 10¹³

Question 60

The value of K_eq for the equilibrium N₂ (g) + O₂ (g) 2 NO (g)
Is 4.2 × 10^-31 at 27 °C. What is the value of K_eq for the equilibrium below?
4 NO (g) 2 N₂ (g) + 2 O₂ (g)

A)5.7 × 10⁶⁰
B)8.4 × 10^-31
C)4.2 × 10³¹
D)8.4 × 10³¹
E)none of the above

Question 61

At 24° C, K_p = 0.080 for the equilibrium: NH₄HS (s) NH₃ (g) + H₂S (g)
A sample of solid NH₄HS is placed in a closed vessel and allowed to equilibrate. Calculate the equilibrium partial pressure (atm)of ammonia, assuming that some solid NH₄HS remains.

A)0.28
B)0.080
C)0.052
D)0.0049
E)3.8

Question 62

The K_p for the reaction below is 1.49 × 10⁸ at 100.0 °C: CO (g)+ Cl₂ (g) → COCl₂ (g)
In an equilibrium mixture of the three gases, P_CO = P_Cl2 = 1.00 × 10^-4 atm. The partial pressure of the product, phosgene (COCl₂), is ________ atm.

A)1.49
B)1.49 × 10¹⁶
C)6.71 × 10^-17
D)1.49 × 10⁴
E)1.49 × 10¹²

Question 63

K_p = 0.0198 at 721 K for the reaction 2HI (g) H₂ (g) + I₂ (g)
In a particular experiment, the partial pressures of H₂ and I₂ at equilibrium are 0.678 and 0.788 atm, respectively. The partial pressure of HI is ________ atm.

A)7.87
B)27.0
C)5.19
D)0.103
E)0.0106

Question 64

Consider the following reaction at equilibrium: 2NH₃ (g) N₂ (g) + 3H₂ (g)ΔH° = +92.4 kJ
Le Châtelier's principle predicts that removing N₂ (g)to the system at equilibrium will result in ________.

A)an increase in the concentration of H₂
B)a decrease in the concentration of H₂
C)removal of all of the H₂
D)a lower partial pressure of H₂
E)an increase in the value of the equilibrium constant

Question 65

Consider the following reaction at equilibrium: 2CO₂ (g) 2CO (g) + O₂ (g)ΔH° = -514 kJ
Le Châtelier's principle predicts that removing O₂ (g)to the reaction container will ________.

A)increase the partial pressure of CO
B)decrease the partial pressure of CO
C)increase the partial pressure of CO₂
D)increase the value of the equilibrium constant
E)decrease the value of the equilibrium constant

Question 66

Dinitrogen tetroxide partially decomposes according to the following equilibrium: N₂O₄ (g) → 2NO₂ (g)
A 1.000-L flask is charged with 9.20 × 10^-3 mol of N₂O₄. At equilibrium, 5.98 × 10^-3 mol of N₂O₄ remains. K_eq for this reaction is ________.

A)0.183
B)0.197
C)0.212
D)6.94 × 10^-3
E)2.96 × 10^-5

Question 67

At 1000.0 K, the equilibrium constant for the reaction 2NO (g) + Br₂ (g) 2NOBr (g)
Is K_p = 0.016. Calculate K_p for the reverse reaction,
2NOBr (g) 2NO (g) + Br₂ (g).

A)0.016
B)1.6 × 10^-4
C)63
D)0.99
E)1.1

Question 68

The value of K_eq for the following reaction is 0.26: A (g) + B (g) C (g) + D (g)
The value of K_eq at the same temperature for the reaction below is ________.
2A (g) + 2B (g) 2C (g) + 2D (g)

A)0.068
B)0.52
C)1.2
D)0.065
E)0.26

Question 69

At elevated temperatures, molecular hydrogen and molecular bromine react to partially form hydrogen bromide: H₂ (g) + Br₂ (g) 2HBr (g)
A mixture of 0.682 mol of H₂ and 0.440 mol of Br₂ is combined in a reaction vessel with a volume of
2.00 L. At equilibrium at 700 K, there are 0.546 mol of H₂ present. At equilibrium, there are ________ mol of Br₂ present in the reaction vessel.

A)0.000
B)0.440
C)0.546
D)0.136
E)0.304

Question 70

The K_eq for the equilibrium below is 7.16 × 10^-2 at 440.0 °C. 2Cl₂ (g) + 2H₂O (g) 4HCl (g) + O₂ (g)
What is the value of K_eq at this temperature for the following reaction?
Cl₂ (g) + H₂O (g) 2HCl (g) + O₂ (g)

A)0.0716
B)5.13 × 10^-3
C)0.268
D)0.0376
E)0.150

Question 71

The expression of K_eq for the following reaction will not include ________. A(g) + B (g) C (l) + D (g)

A)[C]
B)[A]
C)[B]
D)[D]
E)none of the above

Question 72

The value of K_eq for the following reaction is 0.50: A (g) + 2B (g) C (g) + 4D (g)
The value of K_eq at the same temperature for the reaction below is ________. A (g) + B (g) C (g) + 2D (g)

A)7.1 × 10^-1
B)2.5 × 10^-1
C)0.25
D)1.0
E)0.50

Question 73

For the endothermic reaction CaCO₃ (s) CaO (s) + CO₂ (g)
Le Châtelier's principle predicts that ________ will result in an increase in the number of moles of CO₂.

A)increasing the temperature
B)decreasing the temperature
C)increasing the pressure
D)removing some of the CaCO₃(s)
E)none of the above

Question 74

The reaction below is exothermic: 2SO₂ (g) + O₂ (g) 2SO₃ (g)
Le Châtelier's Principle predicts that ________ will result in an increase in the number of moles of SO₃ (g)in the reaction container.

A)increasing the amount of SO₂
B)decreasing the pressure
C)increasing the temperature
D)removing some oxygen
E)increasing the volume of the container

Question 75

Phosphorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorine according to the reaction: PCl₃ (g)+ Cl₂ (g) → PCl₅ (g)
An equilibrium mixture at 450 K contains
P_PCl3 = 0.224 atm,
P_Cl2 = 0.284 atm, and
P_PCl5 = 4.24 atm. What is the value of K_p at this temperature?

A)66.7
B)1.50 × 10^-2
C)2.70 × 10^-1
D)3.74
E)8.36

Question 76

The value of K_eq for the following reaction is 0.16: A (g) + B (g) C (g) + D (g)
The value of K_eq at the same temperature for the reaction below is ________.
3C (g) + 3D (g) 3A (g) + 3B (g)

A)2.4 × 10²
B)2.1
C)4.1 × 10^-3
D)5.3 × 10^-2
E)6.3

Question 77

At 900.0 K, the equilibrium constant (K_p)for the following reaction is 0.345. 2SO₂ + O₂ (g) → 2SO₃ (g)
At equilibrium, the partial pressure of SO₂ is 36.9 atm and that of O₂ is 16.8 atm. The partial pressure of SO₃ is ________ atm.

A)88.8
B)3.89 × 10^-3
C)214
D)5.57 × 10^-4
E)42.4

Question 78

In the coal-gasification process, carbon monoxide is converted to carbon dioxide via the following reaction: CO (g) + H₂O (g) CO₂ (g) + H₂ (g)
In an experiment, 0.35 mol of CO and 0.40 mol of H₂O were placed in a 1.00-L reaction vessel. At equilibrium, there were 0.22 mol of CO remaining. K_eq at the temperature of the experiment is ________.

A)5.5
B)0.75
C)3.5
D)0.28
E)1.0

Question 79

Consider the following chemical reaction: H₂ (g) + I₂ (g) 2HI (g)
At equilibrium in a particular experiment, the concentrations of H₂, I₂, and HI were 0.20 M, 0.034 M, and 0.55 M, respectively. The value of K_eq for this reaction is ________.

A)23
B)81
C)0.0090
D)5.1
E)44

Question 80

Nitrosyl bromide decomposes according to the following equation. 2NOBr (g) 2NO (g) + Br₂ (g)
A sample of NOBr (0.64 mol)was placed in a 1.00-L flask containing no NO or Br₂. At equilibrium the flask contained 0.16 mol of NOBr. How many moles of NO and Br₂, respectively, are in the flask at equilibrium?

A)0.48, 0.24
B)0.48, 0.48
C)0.16, 0.08
D)0.16, 0.16
E)0.24, 0.42