Question 1

For all processes, both q and ΔE will have the same sign.

Accepted Answer

A) True 
 B)False

Question 2

Which one of the following is not a correct formation reaction? (products are correct)

Accepted Answer

A) H 2( g)+ O( g)→ H 2O( l) 
B) ½H 2( g)+ ½Cl 2( g)→ HCl( g) 
C) 6C(graphite)+ 3H 2( g)→ C 6H 6( l) 
D) C(graphite)→ C(diamond) 
E) 6C(graphite)+ 6H 2( g)+ 3O 2( g)→ C 6H 12O 6( s) 
A) H 2( g)+ O( g)→ H 2O( l) 
B) ½H 2( g)+ ½Cl 2( g)→ HCl( g) 
C) 6C(graphite)+ 3H 2( g)→ C 6H 6( l) 
D) C(graphite)→ C(diamond) 
E) 6C(graphite)+ 6H 2( g)+ 3O 2( g)→ C 6H 12O 6( s)

Question 3

Combustion of a hydrocarbon will release more energy than combustion of an equal mass of carbohydrate because

Accepted Answer

A) the C-O and O-H single bonds in carbohydrates are weak. 
B) carbohydrates contain C-O and O-H bonds and hydrocarbons do not. 
C) the total energy of the C-C and C-H bonds in hydrocarbons is greater than the total energy of the C=O and O-H bonds in the combustion products (carbon dioxide and water). 
D) the total energy of the bonds in hydrocarbons is greater than the energy of the bonds in carbohydrates. 
E) hydrocarbons have higher molar masses than carbohydrates. 
A) the C-O and O-H single bonds in carbohydrates are weak. 
B) carbohydrates contain C-O and O-H bonds and hydrocarbons do not. 
C) the total energy of the C-C and C-H bonds in hydrocarbons is greater than the total energy of the C=O and O-H bonds in the combustion products (carbon dioxide and water). 
D) the total energy of the bonds in hydrocarbons is greater than the energy of the bonds in carbohydrates. 
E) hydrocarbons have higher molar masses than carbohydrates.

Question 4

Use the following data to calculate the standard heat (enthalpy) of formation, ΔHf°, of manganese(IV) oxide, MnO2 (s). 2MnO2(s) → 2MnO(s) + O2(g) ΔH = 264 kJ
MnO2(s) + Mn(s) → 2MnO(s) ΔH = −240 kJ

Accepted Answer

A) −504 kJ 
B) −372 kJ 
C) −24 kJ 
D) 24 kJ 
E) 504 kJ 
A) −504 kJ 
B) −372 kJ 
C) −24 kJ 
D) 24 kJ 
E) 504 kJ

Question 5

Calcium hydroxide, which reacts with carbon dioxide to form calcium carbonate, was used by the ancient Romans as mortar in stone structures. The reaction for this process is Ca(OH)2(s) + CO2(g) → CaCO3(s) + H2O(g) ΔH = −69.1 kJ
What is the enthalpy change if 3.8 mol of calcium carbonate is formed?

Accepted Answer

A) −18 kJ 
B) −69 kJ 
C) −73 kJ 
D) −260 kJ 
E) None of these choices are correct. 
A) −18 kJ 
B) −69 kJ 
C) −73 kJ 
D) −260 kJ 
E) None of these choices are correct.

Question 6

15.0 g of ice cubes at 0.0°C are combined with 150 g of liquid water at 70.0°C in a coffee cup calorimeter. Calculate the final temperature reached, assuming no heat loss or gain from the surroundings. (Data: specific heat capacity of H2O(l), c = 4.18 J/g·°C; H2O(s) → H2O(l) ΔH = 6.02 kJ/mol)

Accepted Answer

A) 0.0 
B) 10.6 
C) 30.7 
D) 43.2 
E) 56.4 
A) 0.0 
B) 10.6 
C) 30.7 
D) 43.2 
E) 56.4

Question 7

Nitric acid, which is among the top 15 chemicals produced in the United States, was first prepared over 1200 years ago by heating naturally occurring sodium nitrate (called saltpeter) with sulfuric acid and collecting the vapors produced. Calculate ΔH°rxn for this reaction. ΔH°f [NaNO3(s)] = −467.8 kJ/mol; ΔH°f [NaHSO4(s)] = −1125.5 kJ/mol; ΔH°f [H2SO4(l) = −814.0 kJ/mol; ΔH°f [HNO3(g)] = −135.1 kJ/mol
NaNO3(s) + H2SO4(l) → NaHSO4(s) + HNO3(g)

Accepted Answer

A) −644.2 kJ 
B) −291.4 kJ 
C) −21.2 kJ 
D) 21.2 kJ 
E) 644.2 kJ 
A) −644.2 kJ 
B) −291.4 kJ 
C) −21.2 kJ 
D) 21.2 kJ 
E) 644.2 kJ

Question 8

A system contracts from an initial volume of 15.0 L to a final volume of 10.0 L under a constant external pressure of 0.800 atm. The value of w, in J, is

Accepted Answer

A) −4.0 J. 
B) 4.0 J. 
C) −405 J. 
D) 405 J. 
E) 4.05 × 10 3 J. 
A) −4.0 J. 
B) 4.0 J. 
C) −405 J. 
D) 405 J. 
E) 4.05 × 10 3 J.

Question 9

A Snickers® candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

Accepted Answer

A) 5.0 × 10 −1 kJ 
B) 29 kJ 
C) 5.0 × 10 2 kJ 
D) 1.2 × 10 3 kJ 
E) 5.0 × 10 5 kJ 
A) 5.0 × 10 −1 kJ 
B) 29 kJ 
C) 5.0 × 10 2 kJ 
D) 1.2 × 10 3 kJ 
E) 5.0 × 10 5 kJ

Question 10

Which of the following is not a state function?

Accepted Answer

A) Internal energy 
B) Volume 
C) Work 
D) Pressure 
E) Enthalpy 
A) Internal energy 
B) Volume 
C) Work 
D) Pressure 
E) Enthalpy

Question 11

The highly exothermic thermite reaction, in which aluminum reduces iron(III) oxide to elemental iron, has been used by railroad repair crews to weld rails together. 2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s) ΔH = −850 kJ
What mass of iron is formed when 725 kJ of heat are released?

Accepted Answer

A) 47 g 
B) 65 g 
C) 95 g 
D) 112 g 
E) 130 g 
A) 47 g 
B) 65 g 
C) 95 g 
D) 112 g 
E) 130 g

For all processes, both q and ΔE will have the same sign.

Which one of the following is not a correct formation reaction? (products are correct)

Combustion of a hydrocarbon will release more energy than combustion of an equal mass of carbohydrate because

Use the following data to calculate the standard heat (enthalpy) of formation, ΔH_f°, of manganese(IV) oxide, MnO₂(s). 2MnO₂(s) → 2MnO(s) + O₂(g) ΔH = 264 kJ MnO₂(s) + Mn(s) → 2MnO(s) ΔH = −240 kJ

A system contracts from an initial volume of 15.0 L to a final volume of 10.0 L under a constant external pressure of 0.800 atm. The value of w, in J, is

A Snickers^® candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

Which of the following is not a state function?

The highly exothermic thermite reaction, in which aluminum reduces iron(III) oxide to elemental iron, has been used by railroad repair crews to weld rails together. 2Al(s) + Fe₂O₃(s) → 2Fe(s) + Al₂O₃(s) ΔH = −850 kJ What mass of iron is formed when 725 kJ of heat are released?

Keys to the Study of Chemistry: Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and Reaction Direction

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Exam 6: Thermochemistry: Energy Flow and Chemical Change

For all processes, both q and ΔE will have the same sign.

Which one of the following is not a correct formation reaction? (products are correct)

Combustion of a hydrocarbon will release more energy than combustion of an equal mass of carbohydrate because

Use the following data to calculate the standard heat (enthalpy) of formation, ΔHf°, of manganese(IV) oxide, MnO2 (s). 2MnO2(s) → 2MnO(s) + O2(g) ΔH = 264 kJ MnO2(s) + Mn(s) → 2MnO(s) ΔH = −240 kJ

A system contracts from an initial volume of 15.0 L to a final volume of 10.0 L under a constant external pressure of 0.800 atm. The value of w, in J, is

A Snickers® candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

Which of the following is not a state function?

The highly exothermic thermite reaction, in which aluminum reduces iron(III) oxide to elemental iron, has been used by railroad repair crews to weld rails together. 2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s) ΔH = −850 kJ What mass of iron is formed when 725 kJ of heat are released?

Keys to the Study of Chemistry: Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and Reaction Direction

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Use the following data to calculate the standard heat (enthalpy) of formation, ΔH_f°, of manganese(IV) oxide, MnO₂(s). 2MnO₂(s) → 2MnO(s) + O₂(g) ΔH = 264 kJ MnO₂(s) + Mn(s) → 2MnO(s) ΔH = −240 kJ

A Snickers^® candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

The highly exothermic thermite reaction, in which aluminum reduces iron(III) oxide to elemental iron, has been used by railroad repair crews to weld rails together. 2Al(s) + Fe₂O₃(s) → 2Fe(s) + Al₂O₃(s) ΔH = −850 kJ What mass of iron is formed when 725 kJ of heat are released?