Question 1

A reaction that leads to a decrease in the free energy of the system is always spontaneous.

Accepted Answer

A) True 
 B)False

Question 2

A reaction will be spontaneous at all temperatures under which conditions?

Accepted Answer

A) The reaction is endothermic and accompanied by an increase of disorder. 
B) The reaction is endothermic and accompanied by a decrease in disorder. 
C) The reaction is exothermic and accompanied by an increase in disorder. 
D) The reaction is exothermic and accompanied by a decrease in disorder. 
E) The reaction has a positive value for free energy change. 
A) The reaction is endothermic and accompanied by an increase of disorder. 
B) The reaction is endothermic and accompanied by a decrease in disorder. 
C) The reaction is exothermic and accompanied by an increase in disorder. 
D) The reaction is exothermic and accompanied by a decrease in disorder. 
E) The reaction has a positive value for free energy change.

Question 3

Endothermic reactions are never spontaneous.

Accepted Answer

A) True 
 B)False

Question 4

In the industrial synthesis of ammonia,the equilibrium constant expression may be written as: Calculate the value of this equilibrium constant,if the equilibrium concentration of nitrogen in the reaction mixture at 600°C if [N2] = 4.53 M; [H2]
= 2.49 M; and [NH3] = 7.62 M.
Keq = $\frac { \left[ \mathrm { NH } _ { 3 } \right] ^ { 2 } } { \left[ \mathrm {~N} _ { 2 } \right] \left[ \mathrm { H } _ { 2 } \right] ^ { 3 } }$

Accepted Answer

A) 5.15 
B) 2.07 
C) 0.830 
D) 0.676 
E) 1.44 
A) 5.15 
B) 2.07 
C) 0.830 
D) 0.676 
E) 1.44

Question 5

How many small calories are equivalent to one nutritional Calorie?

Accepted Answer

A) 10 
B) 100 
C) 1,000 
D) 10,000 
E) 100,000 
A) 10 
B) 100 
C) 1,000 
D) 10,000 
E) 100,000

Question 6

In general,which state of matter has the lowest entropy?

Accepted Answer

A) solid 
B) liquid 
C) gas 
D) plasma 
E) supercritical fluid 
A) solid 
B) liquid 
C) gas 
D) plasma 
E) supercritical fluid

Question 7

A reversible reaction is said to have reached equilibrium when which of the following conditions is established?

Accepted Answer

A) The reverse reaction begins to occur. 
B) The rates of the forward and reverse reactions become equal. 
C) The rate of the forward reaction diminishes to zero. 
D) The concentrations of reactants and products become equal. 
E) The reactants are completely consumed. 
A) The reverse reaction begins to occur. 
B) The rates of the forward and reverse reactions become equal. 
C) The rate of the forward reaction diminishes to zero. 
D) The concentrations of reactants and products become equal. 
E) The reactants are completely consumed.

Question 8

LeChatelier's principle states that if a stress is placed on a system at equilibrium,the system will respond by altering the equilibrium composition in such a way as to relieve the stress.

Accepted Answer

A) True 
 B)False

Question 9

Consider the reversible reaction: A(g)⇌ 2B(g) At equilibrium,the concentration of A is 0.381 M and that of B is 0.154 M.What is the value of the equilibrium constant,Keq?

Accepted Answer

A) 0.0622 
B) 0.404 
C) 1.06 
D) 2.47 
E) 16.1 
A) 0.0622 
B) 0.404 
C) 1.06 
D) 2.47 
E) 16.1

Question 10

The reaction shown below is at equilibrium.Use LeChatelier's principle to predict the effect of adding ammonia gas to the equilibrium reaction mixture. N2(g)+ 3H2(g)⇌ 2NH3(g)

Accepted Answer

A) The equilibrium position will remain unchanged. 
B) The equilibrium position will shift to the right. 
C) The equilibrium position will shift to the left. 
D) The equilibrium constant will increase. 
E) All of the nitrogen gas will be used up. 
A) The equilibrium position will remain unchanged. 
B) The equilibrium position will shift to the right. 
C) The equilibrium position will shift to the left. 
D) The equilibrium constant will increase. 
E) All of the nitrogen gas will be used up.

Question 11

Ammonia is synthesized industrially by the reaction of nitrogen and hydrogen in the presence of an iron catalyst according to the reaction equation below.What effect would removing the iron catalyst have on this reaction? 3H2(g)+ N2(g) $\stackrel { \mathrm { Fe } } { \longrightarrow }$ 2NH3(g)

Accepted Answer

A) The reaction would shift to the right,producing more ammonia. 
B) The reaction rate would increase. 
C) The reaction would shift to the left,and consume ammonia. 
D) The reaction rate would decrease. 
E) There would be no effect on the reaction since Fe is not consumed in the reaction. 
A) The reaction would shift to the right,producing more ammonia. 
B) The reaction rate would increase. 
C) The reaction would shift to the left,and consume ammonia. 
D) The reaction rate would decrease. 
E) There would be no effect on the reaction since Fe is not consumed in the reaction.

Question 12

What is the term used to describe the energy barrier the reactants must overcome in order to form products in a chemical reaction?

Accepted Answer

A) energy of inception 
B) activation energy 
C) enthalpy 
D) free energy 
E) energy of formation 
A) energy of inception 
B) activation energy 
C) enthalpy 
D) free energy 
E) energy of formation

Question 13

The equilibrium constant expression for a reaction can be written if the balanced equation is known.

Accepted Answer

A) True 
 B)False

Question 14

Which of the following will NOT increase the rate of a reaction?

Accepted Answer

A) increasing the size of the reaction vessel 
B) adding a catalyst 
C) increasing the temperature 
D) increasing the concentration of the reactants 
E) All of the above will increase the rate of a reaction. 
A) increasing the size of the reaction vessel 
B) adding a catalyst 
C) increasing the temperature 
D) increasing the concentration of the reactants 
E) All of the above will increase the rate of a reaction.

Question 15

A granola bar contains 185 nutritional Calories.How many kilojoules is this? [1 cal = 4.18 J]

Accepted Answer

A) 7.74 × 10-1 kJ 
B) 4.42 × 10-2 kJ 
C) 442 kJ 
D) 773 kJ 
E) 1.85 × 105 Kj 
A) 7.74 × 10-1 kJ 
B) 4.42 × 10-2 kJ 
C) 442 kJ 
D) 773 kJ 
E) 1.85 × 105 Kj

Question 16

For the reaction 2H2(g)+ S2(g)⇌ 2H2S(g),determine the equilibrium constant at 700oC if at this temperature,the equilibrium concentrations are as follows: [H2] = 0.208 M,[S2] = 1.13 × 10-6M,[H2S] = 0.725 M

Accepted Answer

A) 3.22 × 106 
B) 1.08 × 107 
C) 3.49 
D) 4.55 × 10-7 
E) 441 
A) 3.22 × 106 
B) 1.08 × 107 
C) 3.49 
D) 4.55 × 10-7 
E) 441

Question 17

What thermodynamic quantity is the ultimate predictor of reaction spontaneity?

Accepted Answer

A) Enthalpy Change,∆H 
B) Entropy Change,∆S 
C) Free Energy Change,∆G 
D) Entropy Change,∆S and Free Energy Change,∆G. 
E) None of the choices are correct. 
A) Enthalpy Change,∆H 
B) Entropy Change,∆S 
C) Free Energy Change,∆G 
D) Entropy Change,∆S and Free Energy Change,∆G. 
E) None of the choices are correct.

Question 18

Which statement concerning a reversible reaction at equilibrium is FALSE?

Accepted Answer

A) The concentration of the products is equal to the concentration of the reactants. 
B) The forward and reverse reaction rates are equal. 
C) There is no further change in the amount of reactants and products. 
D) A stress to the system would cause the system to shift in the direction that best relieves the stress. 
E) All of the statements are true for a reversible reaction at equilibrium. 
A) The concentration of the products is equal to the concentration of the reactants. 
B) The forward and reverse reaction rates are equal. 
C) There is no further change in the amount of reactants and products. 
D) A stress to the system would cause the system to shift in the direction that best relieves the stress. 
E) All of the statements are true for a reversible reaction at equilibrium.

Question 19

Which of the following statements concerning the reaction below is FALSE? 2HgO(s)→ 2Hg(l)+ O2(g)∆H = 182 kJ

Accepted Answer

A) There is an increase in entropy in this reaction. 
B) This reaction is endothermic. 
C) 182 kJ of energy are required for every two moles of HgO that react. 
D) The energy of the reactants is greater than the energy of the products. 
E) The system absorbs energy from the surroundings in this reaction. 
A) There is an increase in entropy in this reaction. 
B) This reaction is endothermic. 
C) 182 kJ of energy are required for every two moles of HgO that react. 
D) The energy of the reactants is greater than the energy of the products. 
E) The system absorbs energy from the surroundings in this reaction.

Question 20

In general,a liquid state will have higher entropy than a solid state.

Accepted Answer

A) True 
 B)False

Exam 7: Energy,rate and Equilibrium

A reaction that leads to a decrease in the free energy of the system is always spontaneous.

A reaction will be spontaneous at all temperatures under which conditions?

Endothermic reactions are never spontaneous.

How many small calories are equivalent to one nutritional Calorie?

In general,which state of matter has the lowest entropy?

A reversible reaction is said to have reached equilibrium when which of the following conditions is established?

LeChatelier's principle states that if a stress is placed on a system at equilibrium,the system will respond by altering the equilibrium composition in such a way as to relieve the stress.

Consider the reversible reaction: A(g)⇌ 2B(g) At equilibrium,the concentration of A is 0.381 M and that of B is 0.154 M.What is the value of the equilibrium constant,Keq?

The reaction shown below is at equilibrium.Use LeChatelier's principle to predict the effect of adding ammonia gas to the equilibrium reaction mixture. N2(g)+ 3H2(g)⇌ 2NH3(g)

What is the term used to describe the energy barrier the reactants must overcome in order to form products in a chemical reaction?

The equilibrium constant expression for a reaction can be written if the balanced equation is known.

Which of the following will NOT increase the rate of a reaction?

A granola bar contains 185 nutritional Calories.How many kilojoules is this? [1 cal = 4.18 J]

For the reaction 2H2(g)+ S2(g)⇌ 2H2S(g),determine the equilibrium constant at 700oC if at this temperature,the equilibrium concentrations are as follows: [H2] = 0.208 M,[S2] = 1.13 × 10-6M,[H2S] = 0.725 M

What thermodynamic quantity is the ultimate predictor of reaction spontaneity?

Which statement concerning a reversible reaction at equilibrium is FALSE?

Which of the following statements concerning the reaction below is FALSE? 2HgO(s)→ 2Hg(l)+ O2(g)∆H = 182 kJ

In general,a liquid state will have higher entropy than a solid state.

Chemistry - Methods and Measurement

The Structure of the Atom and the Periodic Table

Structure and Properties of Ionic and Covalent Compounds

Calculations, chemical Changes, and the Chemical Equation

States of Matter: Gases, liquids, and Solids

Solutions

Acids and Bases

The Nucleus, radioactivity, and Nuclear Medicine

An Introduction to Organic Chemistry

The Unsaturated Hydrocarbons: Alkenes, alkynes, and Aromatics

Alcohols, phenols, thiols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Carboxylic Acid Derivatives

Amines and Amides

Carbohydrates

Lipids and Their Functions in Biochemical Systems

Protein Structure and Function

Enzymes

Introduction to Molecular Genetics

Carbohydrate Metabolism

Aerobic Respiration and Energy Production

Fatty Acid Metabolism

Filters

The reaction shown below is at equilibrium.Use LeChatelier's principle to predict the effect of adding ammonia gas to the equilibrium reaction mixture. N₂(g)+ 3H₂(g)⇌ 2NH₃(g)

For the reaction 2H₂(g)+ S₂(g)⇌ 2H₂S(g),determine the equilibrium constant at 700oC if at this temperature,the equilibrium concentrations are as follows: [H2] = 0.208 M,[S2] = 1.13 × 10-6M,[H2S] = 0.725 M

Which of the following statements concerning the reaction below is FALSE? 2HgO(s)→ 2Hg(l)+ O₂(g)∆H = 182 kJ