Question 1

Find Kp for the following reaction at 25.0 °C.
SbCl5(g) ⇌ SbCl3(g) + Cl2(g) Kc = 2.51 × 10-2

Accepted Answer

A)  0.614
B)  1.03 × 10-3 
C)  5.15 × 10-2 
D)  9.74 × 102 
E)  39.8

Question 2

For the reaction: 3 Fe(s) + 4 H2O(g) ⇌ Fe3O4(s) + 4 H2(g) what is the effect of adding Fe(s) ?

Accepted Answer

A)  The reaction shifts to the right.
B)  There is no change.
C)  The reaction shifts to the left.
D)  Kp is decreased.
E)  Kp is doubled.

Question 3

Cyclohexane (C6H12) undergoes a molecular rearrangement in the presence of AlCl3 to form methylcyclopentane (MCP) according to the equation:
C6H12 ⇌ MCP
If Kc = 0.143 at 25 °C for this reaction,predict the direction in which the system will shift if the initial concentrations of C6H12 and MCP are 0.0400 mol L-1 and 0.0200 mol L-1,respectively.The system:

Accepted Answer

A)  will shift left
B)  will shift right
C)  is already at equilibrium
D)  is not at equilibrium and will remain in an unequilibrated state

Question 4

For the reaction PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) Kc = 0.0454 at 261 °C.If a vessel is filled with these gases such that the initial concentrations are [PCl5] = 0.20 M,[PCl3] = 0.20 M,and [Cl2] = 2.5 M,in which direction will a reaction occur and why?

Accepted Answer

A)  toward products because Qc = 0.56
B)  toward reactants because Qc = 2.5
C)  toward products because Qc = 2.8
D)  toward reactants because Qc = 0.0454
E)  it is at equilibrium because Qc = 1

Question 5

Phosphorus trichloride and phosphorus pentachloride equilibrate in the presence of molecular chlorine according to the following reaction: 
p at this temperature? A) 66.8 B) 1.50 ×   C) 2.53 × 10-2 D) 1.02 E) 4.63" class="answers-bank-image d-inline" rel="preload" > (g) + p at this temperature? A) 66.8 B) 1.50 ×   C) 2.53 × 10-2 D) 1.02 E) 4.63" class="answers-bank-image d-inline" rel="preload" > (g) → p at this temperature? A) 66.8 B) 1.50 ×   C) 2.53 × 10-2 D) 1.02 E) 4.63" class="answers-bank-image d-inline" rel="preload" > (g) 
An equilibrium mixture at 450 K contains p at this temperature? A) 66.8 B) 1.50 ×   C) 2.53 × 10-2 D) 1.02 E) 4.63" class="answers-bank-image d-inline" rel="preload" > = 0.124 bar, p at this temperature? A) 66.8 B) 1.50 ×   C) 2.53 × 10-2 D) 1.02 E) 4.63" class="answers-bank-image d-inline" rel="preload" > = 0.157 bar,and p at this temperature? A) 66.8 B) 1.50 ×   C) 2.53 × 10-2 D) 1.02 E) 4.63" class="answers-bank-image d-inline" rel="preload" > = 1.30 bar.
What is the value of Kp at this temperature?

Accepted Answer

A)  66.8
B)  1.50 × p at this temperature? 
A)  66.8 
B)  1.50 ×   
C)  2.53 × 10-2 
D)  1.02 
E)  4.63" class="answers-bank-image d-inline" rel="preload" >
C)  2.53 × 10-2
D)  1.02
E)  4.63

Question 6

Given the following reactions,
2 PCl3(g) ⇌ 2 P(g) + 3 Cl2(g) Kc = 0.0667
PCl3(g) + Cl2(g) ⇌ PCl5(g) Kc = 4.0
Calculate Kc for the reaction below.
2 P(g) + 5 Cl2(g) ⇌ 2 PCl5(g)

Accepted Answer

A)  240
B)  1.1
C)  60
D)  23
E)  0.41

Question 7

What is the equilibrium constant expression for:
4 NH3(g) + 5 O2(g) ⇌ 4 NO(g) + 6 H2O(g)

Accepted Answer

A)   3(g) + 5 O2(g) ⇌ 4 NO(g) + 6 H2O(g)  
A)     
B)     
C)     
D)     
E)    " class="answers-bank-image d-inline" rel="preload" >
B)   3(g) + 5 O2(g) ⇌ 4 NO(g) + 6 H2O(g)  
A)     
B)     
C)     
D)     
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C)   3(g) + 5 O2(g) ⇌ 4 NO(g) + 6 H2O(g)  
A)     
B)     
C)     
D)     
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D)   3(g) + 5 O2(g) ⇌ 4 NO(g) + 6 H2O(g)  
A)     
B)     
C)     
D)     
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E)   3(g) + 5 O2(g) ⇌ 4 NO(g) + 6 H2O(g)  
A)     
B)     
C)     
D)     
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Question 8

For the reaction 2 NO2(g) ⇌ N2O4(g) Kp equals ________.

Accepted Answer

A)  Kc 
B)  RT/Kc 
C)  Kc(RT) 
D)  Kc/RT
E)  Kc(RT) 2

Question 9

For the reaction 2 SO2 (g) + O2 (g) ⇌ 2 SO3 (g) ,Kc = 2.8 × 102 at 1000 K.If a vessel is filled with these gases such that the initial concentrations are [SO2] = 0.025 M,[O2] = 0.035 M,and [SO3] = 0.046 M,in which direction will a reaction occur and why?

Accepted Answer

A)  toward products because Qc = 53
B)  toward reactants because Qc = 0.019
C)  toward products because Qc = 97
D)  toward reactants because Qc = 2.8 × 103 
E)  it is at equilibrium because Qc = 1

Question 10

Two moles of NH3 are initially present for the reaction:
2 NH3(g) ⇌ N2(g) + 3 H2(g) 
At equilibrium there is 1.00 mol NH3.How many moles of H2 are present at equilibrium?

Accepted Answer

A)  3.00 moles
B)  1.00 moles
C)  1.50 moles
D)  0.67 moles
E)  0.75 moles

Question 11

Equilibrium constant K is constant except when one varies the:

Accepted Answer

A)  concentrations of the reactants
B)  temperature of the reaction
C)  concentration of the products
D)  partial pressures of the reactants
E)  K always remains constant

Question 12

For the reaction: N2(g) + 2 O2(g) ⇌ 2 NO2(g) ,Kc = 8.3 × 10-10 M-1 at 25 °C.What is the concentration of N2 gas at equilibrium when the concentration of NO2 is five times the concentration of O2 gas?

Accepted Answer

A)  3.3 × 10-11 mol L-1
B)  1.7 × 10-10 mol L-1
C)  6.0 × 109 mol L-1
D)  3.0 × 1010 mol L-1

Question 13

Write the equilibrium constant expression for the following reaction:
N2(g) + 3 H2(g) ⇌ 2 NH3(g)

Accepted Answer

A)   2(g) + 3 H2(g) ⇌ 2 NH3(g)  
A)     
B)     
C)     
D)     
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B)   2(g) + 3 H2(g) ⇌ 2 NH3(g)  
A)     
B)     
C)     
D)     
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C)   2(g) + 3 H2(g) ⇌ 2 NH3(g)  
A)     
B)     
C)     
D)     
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D)   2(g) + 3 H2(g) ⇌ 2 NH3(g)  
A)     
B)     
C)     
D)     
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E)   2(g) + 3 H2(g) ⇌ 2 NH3(g)  
A)     
B)     
C)     
D)     
E)    " class="answers-bank-image d-inline" rel="preload" >

Question 14

The value of the equilibrium constant for a given reaction depends on the initial concentrations of reactants.

Accepted Answer

A) True 
 B)False

Question 15

The concentration of a pure solid is left out of a equilibrium constant expression but a pure liquid is included.

Accepted Answer

A) True 
 B)False

Question 16

0.75 mol of N2 and 1.20 mol of H2 are placed in a 3.0 liter container.When the reaction
N2(g) + 3 H2(g) ⇌ 2 NH3(g) reaches equilibrium,[H2] = 0.100 M.Which of the following is true?

Accepted Answer

A)  [NH3] = 0.150 M
B)  [NH3] = 0.200 M
C)  [N2] = 0.650 M
D)  [N2] = 0.250 M
E)  [NH3] = [H2] = 0.05 M

Question 17

A mixture containing 0.0392 M A(g) and 0.0452 M B(g) is allowed to come to equilibrium at 300 K.The reaction: 3 A(g) + 2 B(g) ⇌ C(g) + D(g) occurs.At equilibrium,[C] = 0.00128 M.What is the value of Kc?

Accepted Answer

A)  2.13 × 10-3 
B)  0.849
C)  20.4
D)  4.91 × 10-2 
E)  470

Question 18

Consider the reaction:
CH4(g) + 4 Cl2(g) ⇌ CCl4(l) + 4 HCl(g) ,ΔrH° = -398 kJ/mol
The equilibrium is displaced to the right if:

Accepted Answer

A)  the temperature is raised
B)  the pressure is lowered
C)  some carbon tetrachloride is removed
D)  some hydrogen chloride is added
E)  some chlorine gas is removed

Question 19

For the isomerization reaction:
Butane ⇌ isobutane
Kp equals 25.0 at 500 °C.If the initial pressures of butane and isobutane are 20.0 atm and 0.0 atm,respectively,what are the pressures of the two gases at equilibrium?

Accepted Answer

A)  P(butane) = 0.77 atm and P(isobutane) = 19.2 atm
B)  P(butane) = 0.80 atm and P(isobutane) = 20.atm
C)  P(butane) = 19.2 atm and P(isobutane) = 0.77 atm
D)  P(butane) = 20 atm and P(isobutane) = 0.80 atm

Question 20

Phosphorus pentachloride decomposes to phosphorus trichloride at high temperatures according to the equation:

-1 PCl5 is added to the flask.If Kc = 1.80,what are the equilibrium concentrations of each gas? A) [PCl5] = 0.00765 mol L-1,[PCl3] = 0.117 mol L-1,and [Cl2] = 0.117 mol L-1 B) [PCl5] = 0.0625 mol L-1,[PCl3] = 0.335 mol L-1,and [Cl2] = 0.335 mol L-1 C) [PCl5] = 1.80 mol L-1,[PCl3] = 1.80 mol L-1,and [Cl2] = 1.80 mol L-1 D) [PCl5] = 3.96 mol L-1,[PCl3] = 3.83 mol L-1,and [Cl2] = 3.83 mol L-1" class="answers-bank-image d-inline" rel="preload" >
At 250 °C 0.125 mol L-1 PCl5 is added to the flask.If Kc = 1.80,what are the equilibrium concentrations of each gas?

Accepted Answer

A)  [PCl5] = 0.00765 mol L-1,[PCl3] = 0.117 mol L-1,and [Cl2] = 0.117 mol L-1
B)  [PCl5] = 0.0625 mol L-1,[PCl3] = 0.335 mol L-1,and [Cl2] = 0.335 mol L-1
C)  [PCl5] = 1.80 mol L-1,[PCl3] = 1.80 mol L-1,and [Cl2] = 1.80 mol L-1
D)  [PCl5] = 3.96 mol L-1,[PCl3] = 3.83 mol L-1,and [Cl2] = 3.83 mol L-1

Exam 15: Principles of Chemical Equilibrium

What is the equilibrium constant expression for: 4 NH₃(g) + 5 O₂(g) ⇌ 4 NO(g) + 6 H₂O(g)

Correct Answer
verified

Correct Answer
verified

For the reaction: N₂(g) + 2 O₂(g) ⇌ 2 NO₂(g) ,K_c = 8.3 × 10^-10 M^-1at 25 °C.What is the concentration of N₂ gas at equilibrium when the concentration of NO₂ is five times the concentration of O₂ gas?

Correct Answer
verified

0.75 mol of N₂ and 1.20 mol of H₂ are placed in a 3.0 liter container.When the reaction N₂(g) + 3 H₂(g) ⇌ 2 NH₃(g) reaches equilibrium,[H₂] = 0.100 M.Which of the following is true?

Correct Answer
verified

For the reaction 2 NO₂(g) ⇌ N₂O₄(g) K_p equals ________.

Correct Answer
verified

The value of the equilibrium constant for a given reaction depends on the initial concentrations of reactants.

Correct Answer
verified

Given the following reactions, 2 PCl₃(g) ⇌ 2 P(g) + 3 Cl₂(g) K_c = 0.0667 PCl₃(g) + Cl₂(g) ⇌ PCl₅(g) K_c = 4.0 Calculate K_c for the reaction below. 2 P(g) + 5 Cl₂(g) ⇌ 2 PCl₅(g)

Correct Answer
verified

Phosphorus trichloride and phosphorus pentachloride equilibrate in the presence of molecular chlorine according to the following reaction: (g) + (g) → (g) An equilibrium mixture at 450 K contains = 0.124 bar, = 0.157 bar,and = 1.30 bar. What is the value of K_p at this temperature?

Correct Answer
verified

Two moles of NH₃ are initially present for the reaction: 2 NH₃(g) ⇌ N₂(g) + 3 H₂(g) At equilibrium there is 1.00 mol NH₃.How many moles of H₂ are present at equilibrium?

Correct Answer
verified

Equilibrium constant K is constant except when one varies the:

Correct Answer
verified

For the reaction 2 SO₂ (g) + O₂ (g) ⇌ 2 SO₃ (g) ,K_c = 2.8 × 10² at 1000 K.If a vessel is filled with these gases such that the initial concentrations are [SO₂] = 0.025 M,[O₂] = 0.035 M,and [SO₃] = 0.046 M,in which direction will a reaction occur and why?

Correct Answer
verified

Phosphorus pentachloride decomposes to phosphorus trichloride at high temperatures according to the equation: At 250 °C 0.125 mol L^-1 PCl₅ is added to the flask.If K_c = 1.80,what are the equilibrium concentrations of each gas?

Correct Answer
verified

A mixture containing 0.0392 M A(g) and 0.0452 M B(g) is allowed to come to equilibrium at 300 K.The reaction: 3 A(g) + 2 B(g) ⇌ C(g) + D(g) occurs.At equilibrium,[C] = 0.00128 M.What is the value of K_c?

Correct Answer
verified

Consider the reaction: CH₄(g) + 4 Cl₂(g) ⇌ CCl₄(l) + 4 HCl(g) ,Δ_rH° = -398 kJ/mol The equilibrium is displaced to the right if:

Correct Answer
verified

Find K_p for the following reaction at 25.0 °C. SbCl₅(g) ⇌ SbCl₃(g) + Cl₂(g) K_c = 2.51 × 10^-2

Correct Answer
verified

Write the equilibrium constant expression for the following reaction: N₂(g) + 3 H₂(g) ⇌ 2 NH₃(g)

Correct Answer
verified

For the isomerization reaction: Butane ⇌ isobutane K_p equals 25.0 at 500 °C.If the initial pressures of butane and isobutane are 20.0 atm and 0.0 atm,respectively,what are the pressures of the two gases at equilibrium?

Correct Answer
verified

The concentration of a pure solid is left out of a equilibrium constant expression but a pure liquid is included.

Correct Answer
verified

For the reaction: 3 Fe(s) + 4 H₂O(g) ⇌ Fe₃O₄(s) + 4 H₂(g) what is the effect of adding Fe(s) ?

Correct Answer
verified

For the reaction PCl₅ (g) ⇌ PCl₃ (g) + Cl₂ (g) K_c = 0.0454 at 261 °C.If a vessel is filled with these gases such that the initial concentrations are [PCl₅] = 0.20 M,[PCl₃] = 0.20 M,and [Cl₂] = 2.5 M,in which direction will a reaction occur and why?

Correct Answer
verified

Exam 15: Principles of Chemical Equilibrium

What is the equilibrium constant expression for: 4 NH3(g) + 5 O2(g) ⇌ 4 NO(g) + 6 H2O(g)

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

For the reaction: N2(g) + 2 O2(g) ⇌ 2 NO2(g) ,Kc = 8.3 × 10-10 M-1 at 25 °C.What is the concentration of N2 gas at equilibrium when the concentration of NO2 is five times the concentration of O2 gas?

Correct AnswerverifiedShow Answer

0.75 mol of N2 and 1.20 mol of H2 are placed in a 3.0 liter container.When the reaction N2(g) + 3 H2(g) ⇌ 2 NH3(g) reaches equilibrium,[H2] = 0.100 M.Which of the following is true?

Correct AnswerverifiedShow Answer

For the reaction 2 NO2(g) ⇌ N2O4(g) Kp equals ________.

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The value of the equilibrium constant for a given reaction depends on the initial concentrations of reactants.

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Given the following reactions, 2 PCl3(g) ⇌ 2 P(g) + 3 Cl2(g) Kc = 0.0667 PCl3(g) + Cl2(g) ⇌ PCl5(g) Kc = 4.0 Calculate Kc for the reaction below. 2 P(g) + 5 Cl2(g) ⇌ 2 PCl5(g)

Correct AnswerverifiedShow Answer

Phosphorus trichloride and phosphorus pentachloride equilibrate in the presence of molecular chlorine according to the following reaction: (g) + (g) → (g) An equilibrium mixture at 450 K contains = 0.124 bar, = 0.157 bar,and = 1.30 bar. What is the value of Kp at this temperature?

Correct AnswerverifiedShow Answer

Two moles of NH3 are initially present for the reaction: 2 NH3(g) ⇌ N2(g) + 3 H2(g) At equilibrium there is 1.00 mol NH3.How many moles of H2 are present at equilibrium?

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Equilibrium constant K is constant except when one varies the:

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For the reaction 2 SO2 (g) + O2 (g) ⇌ 2 SO3 (g) ,Kc = 2.8 × 102 at 1000 K.If a vessel is filled with these gases such that the initial concentrations are [SO2] = 0.025 M,[O2] = 0.035 M,and [SO3] = 0.046 M,in which direction will a reaction occur and why?

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Phosphorus pentachloride decomposes to phosphorus trichloride at high temperatures according to the equation: At 250 °C 0.125 mol L-1 PCl5 is added to the flask.If Kc = 1.80,what are the equilibrium concentrations of each gas?

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A mixture containing 0.0392 M A(g) and 0.0452 M B(g) is allowed to come to equilibrium at 300 K.The reaction: 3 A(g) + 2 B(g) ⇌ C(g) + D(g) occurs.At equilibrium,[C] = 0.00128 M.What is the value of Kc?

Correct AnswerverifiedShow Answer

Consider the reaction: CH4(g) + 4 Cl2(g) ⇌ CCl4(l) + 4 HCl(g) ,ΔrH° = -398 kJ/mol The equilibrium is displaced to the right if:

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Find Kp for the following reaction at 25.0 °C. SbCl5(g) ⇌ SbCl3(g) + Cl2(g) Kc = 2.51 × 10-2

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Write the equilibrium constant expression for the following reaction: N2(g) + 3 H2(g) ⇌ 2 NH3(g)

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For the isomerization reaction: Butane ⇌ isobutane Kp equals 25.0 at 500 °C.If the initial pressures of butane and isobutane are 20.0 atm and 0.0 atm,respectively,what are the pressures of the two gases at equilibrium?

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The concentration of a pure solid is left out of a equilibrium constant expression but a pure liquid is included.

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For the reaction: 3 Fe(s) + 4 H2O(g) ⇌ Fe3O4(s) + 4 H2(g) what is the effect of adding Fe(s) ?

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For the reaction PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) Kc = 0.0454 at 261 °C.If a vessel is filled with these gases such that the initial concentrations are [PCl5] = 0.20 M,[PCl3] = 0.20 M,and [Cl2] = 2.5 M,in which direction will a reaction occur and why?

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What is the equilibrium constant expression for: 4 NH₃(g) + 5 O₂(g) ⇌ 4 NO(g) + 6 H₂O(g)

Correct Answer
verified

Correct Answer
verified

For the reaction: N₂(g) + 2 O₂(g) ⇌ 2 NO₂(g) ,K_c = 8.3 × 10^-10 M^-1at 25 °C.What is the concentration of N₂ gas at equilibrium when the concentration of NO₂ is five times the concentration of O₂ gas?

Correct Answer
verified

0.75 mol of N₂ and 1.20 mol of H₂ are placed in a 3.0 liter container.When the reaction N₂(g) + 3 H₂(g) ⇌ 2 NH₃(g) reaches equilibrium,[H₂] = 0.100 M.Which of the following is true?

Correct Answer
verified

For the reaction 2 NO₂(g) ⇌ N₂O₄(g) K_p equals ________.

Correct Answer
verified

Correct Answer
verified

Given the following reactions, 2 PCl₃(g) ⇌ 2 P(g) + 3 Cl₂(g) K_c = 0.0667 PCl₃(g) + Cl₂(g) ⇌ PCl₅(g) K_c = 4.0 Calculate K_c for the reaction below. 2 P(g) + 5 Cl₂(g) ⇌ 2 PCl₅(g)

Correct Answer
verified

Phosphorus trichloride and phosphorus pentachloride equilibrate in the presence of molecular chlorine according to the following reaction: (g) + (g) → (g) An equilibrium mixture at 450 K contains = 0.124 bar, = 0.157 bar,and = 1.30 bar. What is the value of K_p at this temperature?

Correct Answer
verified

Two moles of NH₃ are initially present for the reaction: 2 NH₃(g) ⇌ N₂(g) + 3 H₂(g) At equilibrium there is 1.00 mol NH₃.How many moles of H₂ are present at equilibrium?

Correct Answer
verified

Correct Answer
verified

For the reaction 2 SO₂ (g) + O₂ (g) ⇌ 2 SO₃ (g) ,K_c = 2.8 × 10² at 1000 K.If a vessel is filled with these gases such that the initial concentrations are [SO₂] = 0.025 M,[O₂] = 0.035 M,and [SO₃] = 0.046 M,in which direction will a reaction occur and why?

Correct Answer
verified

Phosphorus pentachloride decomposes to phosphorus trichloride at high temperatures according to the equation: At 250 °C 0.125 mol L^-1 PCl₅ is added to the flask.If K_c = 1.80,what are the equilibrium concentrations of each gas?

Correct Answer
verified

A mixture containing 0.0392 M A(g) and 0.0452 M B(g) is allowed to come to equilibrium at 300 K.The reaction: 3 A(g) + 2 B(g) ⇌ C(g) + D(g) occurs.At equilibrium,[C] = 0.00128 M.What is the value of K_c?

Correct Answer
verified

Consider the reaction: CH₄(g) + 4 Cl₂(g) ⇌ CCl₄(l) + 4 HCl(g) ,Δ_rH° = -398 kJ/mol The equilibrium is displaced to the right if:

Correct Answer
verified

Find K_p for the following reaction at 25.0 °C. SbCl₅(g) ⇌ SbCl₃(g) + Cl₂(g) K_c = 2.51 × 10^-2

Correct Answer
verified

Write the equilibrium constant expression for the following reaction: N₂(g) + 3 H₂(g) ⇌ 2 NH₃(g)

Correct Answer
verified

For the isomerization reaction: Butane ⇌ isobutane K_p equals 25.0 at 500 °C.If the initial pressures of butane and isobutane are 20.0 atm and 0.0 atm,respectively,what are the pressures of the two gases at equilibrium?

Correct Answer
verified

Correct Answer
verified

For the reaction: 3 Fe(s) + 4 H₂O(g) ⇌ Fe₃O₄(s) + 4 H₂(g) what is the effect of adding Fe(s) ?

Correct Answer
verified

For the reaction PCl₅ (g) ⇌ PCl₃ (g) + Cl₂ (g) K_c = 0.0454 at 261 °C.If a vessel is filled with these gases such that the initial concentrations are [PCl₅] = 0.20 M,[PCl₃] = 0.20 M,and [Cl₂] = 2.5 M,in which direction will a reaction occur and why?

Correct Answer
verified