Question 1

The rate of a chemical reaction increases with an increase in temperature.Which of the following correctly explains why?

Accepted Answer

A) At higher temperatures,the activation energy is increased. 
B) At higher temperatures,the activation energy is decreased. 
C) At higher temperatures,more reactant molecules are present and collisions occur more frequently. 
D) At higher temperatures,reactant molecules move faster,collide more often,and produce more effective collisions. 
E) At higher temperatures,a catalyst is usually present. 
A) At higher temperatures,the activation energy is increased. 
B) At higher temperatures,the activation energy is decreased. 
C) At higher temperatures,more reactant molecules are present and collisions occur more frequently. 
D) At higher temperatures,reactant molecules move faster,collide more often,and produce more effective collisions. 
E) At higher temperatures,a catalyst is usually present.

Question 2

When a cold-pack is activated,a chemical reaction occurs and the temperature of the pack contents drops sharply.Which of the following is a correct description of the reaction occurring in the pack?

Accepted Answer

A) The reaction is exothermic; ∆H ° > 0. B) The reaction is exothermic; ∆H ° 0. D) The reaction is endothermic; ∆H ° < 0. E) None of the choices are correct. A) The reaction is exothermic; ∆H ° > 0. B) The reaction is exothermic; ∆H ° 0. D) The reaction is endothermic; ∆H ° < 0. E) None of the choices are correct.

Question 3

Which of the following represents an exothermic reaction?

Accepted Answer

A) A(g)+ B(g)→ 2C(g)∆H = +100 kcal 
B) A(g)→ B(g)+ 33 kcal 
C) 50 kcal + 2A(g)→ C(g)+ D(s) 
D) A(g)+ B(g)→ 2C(g)∆H = +100 kcal and A(g)→ B(g)+ 33 kcal are exothermic reactions. 
E) A(g)+ B(g)→ 2C(g)∆H = +100 kcal and 50 kcal + 2A(g)→ C(g)+ D(s)are exothermic reactions. 
A) A(g)+ B(g)→ 2C(g)∆H = +100 kcal 
B) A(g)→ B(g)+ 33 kcal 
C) 50 kcal + 2A(g)→ C(g)+ D(s) 
D) A(g)+ B(g)→ 2C(g)∆H = +100 kcal and A(g)→ B(g)+ 33 kcal are exothermic reactions. 
E) A(g)+ B(g)→ 2C(g)∆H = +100 kcal and 50 kcal + 2A(g)→ C(g)+ D(s)are exothermic reactions.

Question 4

What is the equilibrium constant expression for the reaction shown below?

Accepted Answer

A) Keq = $\frac { [ \mathrm { MgO } ] \left[ \mathrm { CO } _ { 2 } \right] } { \left[ \mathrm { MgCO } _ { 3 } \right] }$ 
B) Keq = $\frac { \left[ \mathrm { MgCO } _ { 3 } \right] } { [ \mathrm { MgO } ] \left[ \mathrm { CO } _ { 2 } \right] }$ 
C) Keq = $\frac { [ \mathrm { MgO } ] + \left[ \mathrm { CO } _ { 2 } \right] } { \left[ \mathrm { MgCO } _ { 3 } \right] }$ 
D) Keq = [MgO][CO2] 
E) Keq = [CO2] 
A) Keq = $\frac { [ \mathrm { MgO } ] \left[ \mathrm { CO } _ { 2 } \right] } { \left[ \mathrm { MgCO } _ { 3 } \right] }$ 
B) Keq = $\frac { \left[ \mathrm { MgCO } _ { 3 } \right] } { [ \mathrm { MgO } ] \left[ \mathrm { CO } _ { 2 } \right] }$ 
C) Keq = $\frac { [ \mathrm { MgO } ] + \left[ \mathrm { CO } _ { 2 } \right] } { \left[ \mathrm { MgCO } _ { 3 } \right] }$ 
D) Keq = [MgO][CO2] 
E) Keq = [CO2]

Question 5

A catalyst increases the equilibrium constant for a reaction.

Accepted Answer

A) True 
 B)False

Question 6

The amount of heat necessary to raise 1 gram of a substance by 1 degree Celsius is known as which of the following?

Accepted Answer

A) enthalpy 
B) activation energy 
C) specific heat 
D) heat of vaporization 
E) free energy 
A) enthalpy 
B) activation energy 
C) specific heat 
D) heat of vaporization 
E) free energy

Question 7

Which one of the following actions can alter the activation energy of a reaction?

Accepted Answer

A) changing the temperature 
B) changing the concentration of reactants 
C) changing the concentration of products 
D) changing the size of the reaction vessel 
E) adding a catalyst 
A) changing the temperature 
B) changing the concentration of reactants 
C) changing the concentration of products 
D) changing the size of the reaction vessel 
E) adding a catalyst

The rate of a chemical reaction increases with an increase in temperature.Which of the following correctly explains why?

When a cold-pack is activated,a chemical reaction occurs and the temperature of the pack contents drops sharply.Which of the following is a correct description of the reaction occurring in the pack?

Which of the following represents an exothermic reaction?

What is the equilibrium constant expression for the reaction shown below?

A catalyst increases the equilibrium constant for a reaction.

The amount of heat necessary to raise 1 gram of a substance by 1 degree Celsius is known as which of the following?

Which one of the following actions can alter the activation energy of a reaction?

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

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Exam 7: Energy,rate and Equilibrium

The rate of a chemical reaction increases with an increase in temperature.Which of the following correctly explains why?

When a cold-pack is activated,a chemical reaction occurs and the temperature of the pack contents drops sharply.Which of the following is a correct description of the reaction occurring in the pack?

Which of the following represents an exothermic reaction?

What is the equilibrium constant expression for the reaction shown below?

A catalyst increases the equilibrium constant for a reaction.

The amount of heat necessary to raise 1 gram of a substance by 1 degree Celsius is known as which of the following?

Which one of the following actions can alter the activation energy of a reaction?

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