Question 1

When a reaction system reaches equilibrium, the forward and reverse reactions stop.

Accepted Answer

A) True 
 B)False  False

Question 2

Hydrogen peroxide may decompose to form water and oxygen gas according to the following reaction. 2H2O2(g)   2H2O(g) + O2(g)
In a particular experiment, 1.75 moles of H2O2 were placed in a 2.5-L reaction chamber at 307ºC.After equilibrium was reached, 1.20 moles of H2O2 remained.What is K for the reaction?

Accepted Answer

A) 2.0 × 10−4 
B) 2.3 × 10−2 
C) 2.4 × 10-3 
D) 5.5 × 10−3 
E) 3.9 × 10−4 
A) 2.0 × 10−4 
B) 2.3 × 10−2 
C) 2.4 × 10-3 
D) 5.5 × 10−3 
E) 3.9 × 10−4 B

Question 3

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

Accepted Answer

A) True 
 B)False  True

Question 4

For the nitrogen fixation reaction, 3H2(g) + N2(g)   2NH3(g), K = 6.0 × 10−2 at 500°C.If 0.250 M H2 and 0.050 M NH3 are present at equilibrium, what is the equilibrium concentration of N2?

Accepted Answer

A) 3.3 M 
B) 2.7 M 
C) 0.20 M 
D) 0.083 M 
E) 0.058 M 
A) 3.3 M 
B) 2.7 M 
C) 0.20 M 
D) 0.083 M 
E) 0.058 M

Question 5

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

Accepted Answer

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

Question 6

Which reaction shown will have the highest concentration of reactants at equilibrium?

Accepted Answer

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

Question 7

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 K for this reaction? CO(g) + Br2(g)   COBr2(g)

Accepted Answer

A) 5.23 
B) 2.14 
C) 1.17 
D) 0.467 
E) 0.191 
A) 5.23 
B) 2.14 
C) 1.17 
D) 0.467 
E) 0.191

Question 8

What is defined as a fraction with equilibrium product concentrations in the numerator and equilibrium reactant concentrations in the denominator and each concentration raised to a power equal to the corresponding stoichiometric coefficient in the balanced chemical equation?

Accepted Answer

A) Reversibility expression 
B) Reaction expression 
C) Equilibrium expression 
D) Product quotient 
E) Mass action 
A) Reversibility expression 
B) Reaction expression 
C) Equilibrium expression 
D) Product quotient 
E) Mass action

Question 9

Which reaction shown will have the highest concentration of products at equilibrium?

Accepted Answer

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

Question 10

At elevated temperatures, hydrogen iodide may decompose to form hydrogen gas and iodine gas, as follows. 2HI(g)   H2(g) + I2(g)
In a particular experiment, the concentrations at equilibrium were measured to be [HI] = 0.85 mol/L, [I2] = 0.60 mol/L, and [H2] = 0.27 mol/L.What is K for the above reaction?

Accepted Answer

A) 5.3 
B) 0.22 
C) 4.5 
D) 0.19 
E) 1.6× 102 
A) 5.3 
B) 0.22 
C) 4.5 
D) 0.19 
E) 1.6× 102

Question 11

Write the equilibrium constant expression for the reaction shown. 2NOCl(g)  ⇌ 2NO(g) + Cl2(g)

Accepted Answer

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

Question 12

Compounds A, B, and C react according to the following equation.3A(g) + 2B(g)   2C(g) At 100°C a mixture of these gases at equilibrium showed that [A] = 0.855 M, [B] = 1.23 M, and [C] = 1.75 M.What is the value of K for this reaction?

Accepted Answer

A) 0.309 
B) 0.601 
C) 1.66 
D) 2.25 
E) 3.24 
A) 0.309 
B) 0.601 
C) 1.66 
D) 2.25 
E) 3.24

Question 13

At 450°C, tert-butyl alcohol decomposes into water and isobutene.(CH3)3COH(g)   (CH3)2CCH2(g) + H2O(g) A reaction vessel contains these compounds at equilibrium.What will happen if the volume of the container is reduced by 50% at constant temperature?

Accepted Answer

A) The forward reaction will proceed in order to reestablish equilibrium. 
B) The reverse reaction will proceed in order to reestablish equilibrium. 
C) No change occurs. 
D) The equilibrium constant will increase. 
E) The equilibrium constant will decrease. 
A) The forward reaction will proceed in order to reestablish equilibrium. 
B) The reverse reaction will proceed in order to reestablish equilibrium. 
C) No change occurs. 
D) The equilibrium constant will increase. 
E) The equilibrium constant will decrease.

Question 14

Determine the balanced chemical equation that corresponds to the given equilibrium expression.

Accepted Answer

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

Question 15

Which substances are included in the equilibrium constant expression, Kc?

Accepted Answer

A) Only pure solids 
B) Only pure liquids 
C) Only pure solids and liquids 
D) Only gases and dissolved substances 
E) All participating substances 
A) Only pure solids 
B) Only pure liquids 
C) Only pure solids and liquids 
D) Only gases and dissolved substances 
E) All participating substances

Question 16

The equilibrium constant expression for the reaction CuO(s) + H2(g)   Cu(s) + H2O(g) is K = [H2]/[H2O].

Accepted Answer

A) True 
 B)False

Question 17

Write the equilibrium constant expression for the reaction shown.

Accepted Answer

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

Question 18

Determine the balanced chemical equation that corresponds to the given equilibrium expression.

Accepted Answer

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

Question 19

A 6.0-L vessel was found to contain 1.0 mol BrCl3, 2.0 mol Br2 and 6.0 mol Cl2.What is the equilibrium constant, K, for this equilibrium mixture for the reaction 2BrCl3(g)   Br2(g) + 3Cl2(g)?

Accepted Answer

A) 0.014 
B) 108 
C) 18 
D) 12 
E) 432 
A) 0.014 
B) 108 
C) 18 
D) 12 
E) 432

Question 20

When the following reaction is at equilibrium 2NOCl(g)   2NO(g) + Cl2(g)
then [NO]2 [Cl2] = K [NOCl]2.

Accepted Answer

A) True 
 B)False

When a reaction system reaches equilibrium, the forward and reverse reactions stop.

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

For the nitrogen fixation reaction, 3H₂(g) + N₂(g) 2NH₃(g), K = 6.0 × 10⁻² at 500°C.If 0.250 M H₂ and 0.050 M NH₃ are present at equilibrium, what is the equilibrium concentration of N₂?

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

Which reaction shown will have the highest concentration of reactants at equilibrium?

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 K for this reaction? CO(g) + Br₂(g) COBr₂(g)

What is defined as a fraction with equilibrium product concentrations in the numerator and equilibrium reactant concentrations in the denominator and each concentration raised to a power equal to the corresponding stoichiometric coefficient in the balanced chemical equation?

Which reaction shown will have the highest concentration of products at equilibrium?

Write the equilibrium constant expression for the reaction shown. 2NOCl(g) ⇌ 2NO(g) + Cl₂(g)

Compounds A, B, and C react according to the following equation.3A(g) + 2B(g) 2C(g) At 100°C a mixture of these gases at equilibrium showed that [A] = 0.855 M, [B] = 1.23 M, and [C] = 1.75 M.What is the value of K for this reaction?

At 450°C, tert-butyl alcohol decomposes into water and isobutene.(CH₃)₃COH(g) (CH₃)₂CCH₂(g) + H₂O(g) A reaction vessel contains these compounds at equilibrium.What will happen if the volume of the container is reduced by 50% at constant temperature?

Determine the balanced chemical equation that corresponds to the given equilibrium expression.

Which substances are included in the equilibrium constant expression, K_c?

The equilibrium constant expression for the reaction CuO(s) + H₂(g) Cu(s) + H₂O(g) is K = [H₂]/[H₂O].

Write the equilibrium constant expression for the reaction shown.

Determine the balanced chemical equation that corresponds to the given equilibrium expression.

A 6.0-L vessel was found to contain 1.0 mol BrCl3, 2.0 mol Br2 and 6.0 mol Cl2.What is the equilibrium constant, K, for this equilibrium mixture for the reaction 2BrCl3(g) Br2(g) + 3Cl2(g)?

When the following reaction is at equilibrium 2NOCl(g) 2NO(g) + Cl₂(g) then [NO]² [Cl₂] = K [NOCl]².

Atoms and Elements

Electrons and the Periodic Table

Compounds and Chemical Bonds

How Chemists Use Numbers

The Mole and Chemical Formulas

Molecular Shape

Solids, Liquids, and Phase Changes

Gases

Physical Properties of Solutions

Chemical Reactions and Chemical Equations

Using Balanced Chemical Equations

Acids and Bases

Organic Chemistry

Biochemistry

Nuclear Chemistry

Electrochemistry

Filters

Exam 13: Equilibrium

When a reaction system reaches equilibrium, the forward and reverse reactions stop.

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

For the nitrogen fixation reaction, 3H2(g) + N2(g) 2NH3(g), K = 6.0 × 10−2 at 500°C.If 0.250 M H2 and 0.050 M NH3 are present at equilibrium, what is the equilibrium concentration of N2?

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

Which reaction shown will have the highest concentration of reactants at equilibrium?

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 K for this reaction? CO(g) + Br2(g) COBr2(g)

What is defined as a fraction with equilibrium product concentrations in the numerator and equilibrium reactant concentrations in the denominator and each concentration raised to a power equal to the corresponding stoichiometric coefficient in the balanced chemical equation?

Which reaction shown will have the highest concentration of products at equilibrium?

Write the equilibrium constant expression for the reaction shown. 2NOCl(g) ⇌ 2NO(g) + Cl2(g)

Compounds A, B, and C react according to the following equation.3A(g) + 2B(g) 2C(g) At 100°C a mixture of these gases at equilibrium showed that [A] = 0.855 M, [B] = 1.23 M, and [C] = 1.75 M.What is the value of K for this reaction?

At 450°C, tert-butyl alcohol decomposes into water and isobutene.(CH3)3COH(g) (CH3)2CCH2(g) + H2O(g) A reaction vessel contains these compounds at equilibrium.What will happen if the volume of the container is reduced by 50% at constant temperature?

Determine the balanced chemical equation that corresponds to the given equilibrium expression.

Which substances are included in the equilibrium constant expression, Kc?

The equilibrium constant expression for the reaction CuO(s) + H2(g) Cu(s) + H2O(g) is K = [H2]/[H2O].

Write the equilibrium constant expression for the reaction shown.

Determine the balanced chemical equation that corresponds to the given equilibrium expression.

A 6.0-L vessel was found to contain 1.0 mol BrCl3, 2.0 mol Br2 and 6.0 mol Cl2.What is the equilibrium constant, K, for this equilibrium mixture for the reaction 2BrCl3(g) Br2(g) + 3Cl2(g)?

When the following reaction is at equilibrium 2NOCl(g) 2NO(g) + Cl2(g) then [NO]2 [Cl2] = K [NOCl]2.

Atoms and Elements

Electrons and the Periodic Table

Compounds and Chemical Bonds

How Chemists Use Numbers

The Mole and Chemical Formulas

Molecular Shape

Solids, Liquids, and Phase Changes

Gases

Physical Properties of Solutions

Chemical Reactions and Chemical Equations

Using Balanced Chemical Equations

Acids and Bases

Organic Chemistry

Biochemistry

Nuclear Chemistry

Electrochemistry

Filters

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

For the nitrogen fixation reaction, 3H₂(g) + N₂(g) 2NH₃(g), K = 6.0 × 10⁻² at 500°C.If 0.250 M H₂ and 0.050 M NH₃ are present at equilibrium, what is the equilibrium concentration of N₂?

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

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 K for this reaction? CO(g) + Br₂(g) COBr₂(g)

Write the equilibrium constant expression for the reaction shown. 2NOCl(g) ⇌ 2NO(g) + Cl₂(g)

At 450°C, tert-butyl alcohol decomposes into water and isobutene.(CH₃)₃COH(g) (CH₃)₂CCH₂(g) + H₂O(g) A reaction vessel contains these compounds at equilibrium.What will happen if the volume of the container is reduced by 50% at constant temperature?

Which substances are included in the equilibrium constant expression, K_c?

The equilibrium constant expression for the reaction CuO(s) + H₂(g) Cu(s) + H₂O(g) is K = [H₂]/[H₂O].

When the following reaction is at equilibrium 2NOCl(g) 2NO(g) + Cl₂(g) then [NO]² [Cl₂] = K [NOCl]².