Question 1

A system which undergoes an adiabatic change and does work on the surroundings has

Accepted Answer

A) w 0, F1F1F1S1F1F1F10E > 0. C) w > 0, F1F1F1S1F1F1F10E 0. E) w < 0, F1F1F1S1F1F1F10E < 0. A) w 0, F1F1F1S1F1F1F10E > 0. C) w > 0, F1F1F1S1F1F1F10E 0. E) w < 0, F1F1F1S1F1F1F10E < 0.

Question 2

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 F1F1F1S1F1F1F10H°rxn for this reaction. F1F1F1S1F1F1F10H°f [NaNO3(s)] = -467.8 kJ/mol; F1F1F1S1F1F1F10H°f [NaHSO4(s)] = -1125.5 kJ/mol; F1F1F1S1F1F1F10H°f [H2SO4(l) = -814.0 kJ/mol; F1F1F1S1F1F1F10H°f [HNO3(g)] = -135.1 kJ/mol
NaNO3(s) + H2SO4(l) F1F1F1S1F1F1F10 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 3

The specific heat capacity c of a metal is approximately related to its molar mass   as follows: c ×   = 3R, where R is the universal gas constant, 8.314 J/molF1F1F1S1F1F1F10K. Use this relationship to identify the metal which has a specific heat capacity of 0.900 J/gF1F1F1S1F1F1F10K.

Accepted Answer

A)  Li 
B)  Sn 
C)  Ca 
D)  Al 
E)  U 
A)  Li 
B)  Sn 
C)  Ca 
D)  Al 
E)  U

Question 4

In which of the following processes is F1F1F1S1F1F1F10H = F1F1F1S1F1F1F10E ?

Accepted Answer

A)  Two moles of ammonia gas are cooled from 325°C to 300°C at 1.2 atm. 
B)  One gram of water is vaporized at 100°C and 1 atm. 
C)  Two moles of hydrogen iodide gas react to form hydrogen gas and iodine gas in a 40-L container. 
D)  Calcium carbonate is heated to form calcium oxide and carbon dioxide in a container with variable volume. 
E)  One mole of solid carbon dioxide sublimes to the gas phase. 
A)  Two moles of ammonia gas are cooled from 325°C to 300°C at 1.2 atm. 
B)  One gram of water is vaporized at 100°C and 1 atm. 
C)  Two moles of hydrogen iodide gas react to form hydrogen gas and iodine gas in a 40-L container. 
D)  Calcium carbonate is heated to form calcium oxide and carbon dioxide in a container with variable volume. 
E)  One mole of solid carbon dioxide sublimes to the gas phase.

Question 5

The Starship Enterprise is caught in a time warp and Spock is forced to use the primitive techniques of the 20th century to determine the specific heat capacity of an unknown mineral. The 307-g sample was heated to 98.7°C and placed into a calorimeter containing 72.4 g of water at 23.6°C. The heat capacity of the calorimeter was 15.7 J/K. The final temperature in the calorimeter was 32.4°C. What is the specific heat capacity of the mineral?

Accepted Answer

A)  0.124 J/(g·K) 
B)  0.131 J/(g·K) 
C)  0.138 J/(g·K) 
D)  0.145 J/(g·K) 
E)  none of the above 
A)  0.124 J/(g·K) 
B)  0.131 J/(g·K) 
C)  0.138 J/(g·K) 
D)  0.145 J/(g·K) 
E)  none of the above

Question 6

In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (Data: H2O(l) F1F1F1S1F1F1F10 H2O(g) F1F1F1S1F1F1F10H = 44.01 kJ/mol.)

Accepted Answer

A)  315 g water vapor was produced. 
B)  17.5 g of water vapor was produced. 
C)  17.5 mol of water vapor was produced. 
D)  17.5 mol of liquid water was produced. 
E)  17.5 g of liquid water was produced. 
A)  315 g water vapor was produced. 
B)  17.5 g of water vapor was produced. 
C)  17.5 mol of water vapor was produced. 
D)  17.5 mol of liquid water was produced. 
E)  17.5 g of liquid water was produced.

Question 7

The compound carbon suboxide, C3O2, is a gas at room temperature. Use the data supplied to calculate the heat of formation of carbon suboxide. 
(Data: 2CO(g) + C(s) F1F1F1S1F1F1F10 C3O2(g) F1F1F1S1F1F1F10H° = 127.3 kJ/mol
And: F1F1F1S1F1F1F10Hf° of CO(g) = -110.5 kJ/mol)

Accepted Answer

A)  116.8 
B)  -93.7 
C)  227.8 
D)  -348.3 
E)  93.7 
A)  116.8 
B)  -93.7 
C)  227.8 
D)  -348.3 
E)  93.7

Question 8

When 1.00 g of solid NH4Cl is dissolved in 25.00 g of water contained in a coffee cup calorimeter, both reagents initially being at 25.0°C, the temperature falls to 22.4°C. Assuming that the heat capacity of the ammonium chloride solution is 4.18 J/(g·K), calculate the heat (enthalpy) of solution of NH4Cl, (a) in J/g and (b) in kJ/mol.

Accepted Answer

Question 9

Use the following data to calculate the standard heat (enthalpy) of formation, F1F1F1S1F1F1F10H°f , of manganese(IV) oxide, MnO2 (s). 
2MnO2(s) F1F1F1S1F1F1F10 2MnO(s) + O2(g) F1F1F1S1F1F1F10H = 264 kJ
MnO2(s) + Mn(s) F1F1F1S1F1F1F10 2MnO(s) F1F1F1S1F1F1F10H = -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 10

Which one of the following relationships is always correct?

Accepted Answer

A)  potential energy + kinetic energy = constant 
B)  E = q + w 
C)  .F1F1F1S1F1F1F10E = F1F1F1S1F1F1F10H - PF1F1F1S1F1F1F10V 
D)  H = E + PV 
E)  .F1F1F1S1F1F1F10H = qv 
A)  potential energy + kinetic energy = constant 
B)  E = q + w 
C)  .F1F1F1S1F1F1F10E = F1F1F1S1F1F1F10H - PF1F1F1S1F1F1F10V 
D)  H = E + PV 
E)  .F1F1F1S1F1F1F10H = qv

Question 11

a. Starting from the equation H = E + PV, show how the relationship F1F1F1S1F1F1F10H = qp is derived. Clearly indicate any necessary assumptions or conditions.
b. In one sentence, state in full what is meant by the equation: F1F1F1S1F1F1F10H = qp.

Accepted Answer

a. Since H = E + PV (defining equation f

Question 12

A system expands from a volume of 1.00 L to 2.00 L against a constant external pressure of 1.00 atm. The work (w) done by the system, in J, is

Accepted Answer

A)  1.00 J. 
B)  2.00 J. 
C)  1.01 × 102 J. 
D)  1.01 × 105 J. 
E)  none of the above. 
A)  1.00 J. 
B)  2.00 J. 
C)  1.01 × 102 J. 
D)  1.01 × 105 J. 
E)  none of the above.

Question 13

F1F1F1S1F1F1F10E values obtained by bomb calorimetry can be converted to give accurate F1F1F1S1F1F1F10H values.

Accepted Answer

A) True 
 B)False

Question 14

Ethanol, C2H5OH, is being promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the F1F1F1S1F1F1F10H°rxn for the combustion of ethanol. 
(F1F1F1S1F1F1F10H°f [C2H5OH(l)] = -277.7 kJ/mol; F1F1F1S1F1F1F10H°f [CO2(g)] = -393.5 kJ/mol; F1F1F1S1F1F1F10H°f [H2O(g)] = -241.8 kJ/mol)

Accepted Answer

A)  -1234.7 kJ 
B)  -751.1 kJ 
C)  -357.6 kJ 
D)  357.6 kJ 
E)  1234.7 kJ 
A)  -1234.7 kJ 
B)  -751.1 kJ 
C)  -357.6 kJ 
D)  357.6 kJ 
E)  1234.7 kJ

Question 15

F1F1F1S1F1F1F10H does not depend on the path of a reaction, but F1F1F1S1F1F1F10E does.

Accepted Answer

A) True 
 B)False

Question 16

a. A gas sample absorbs 53 kJ of heat and does 18 kJ of work. Calculate the change in its internal energy.
b. A system expands against a constant pressure of 1.50 atm, from an initial volume of 1.00 L to a final volume of 10.0 L. Calculate the work (w) involved in this process, in kJ.

Accepted Answer

a. F1F1F1S

Question 17

Diborane (B2H6) has been considered as a possible rocket fuel. Calculate F1F1F1S1F1F1F10H° for the reaction
B2H6(g) F1F1F1S1F1F1F10 2B(s) + 3H2(g)
using the following data:     O2(g) F1F1F1S1F1F1F10 H2O(g)
-242

Accepted Answer

F1F1F1S1F

Question 18

A mass of 1.250 g of benzoic acid (C7H6O2) was completely combusted in a bomb calorimeter. If the heat capacity of the calorimeter was 10.134 kJ/K and the heat of combustion of benzoic acid is -3226 kJ/mol, calculate (to three decimal places) the temperature increase that should have occurred in the apparatus.

Accepted Answer

Temperatur

Question 19

Starting from equations relating pressure to force and force to work, derive the relationship w = - PF1F1F1S1F1F1F10V, explaining the steps in your argument.

Accepted Answer

Consider the system being contained in a

Question 20

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g·K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132°C to 85°C.

Accepted Answer

A)  -1900 kJ 
B)  -420 kJ 
C)  -99 kJ 
D)  -0.42 kJ 
E)  -4.2 × 10-6 kJ 
A)  -1900 kJ 
B)  -420 kJ 
C)  -99 kJ 
D)  -0.42 kJ 
E)  -4.2 × 10-6 kJ

A system which undergoes an adiabatic change and does work on the surroundings has

The specific heat capacity c of a metal is approximately related to its molar mass as follows: c × = 3R, where R is the universal gas constant, 8.314 J/molK. Use this relationship to identify the metal which has a specific heat capacity of 0.900 J/gK.

In which of the following processes is H = E ?

In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (Data: H₂O(l)  H₂O(g) H = 44.01 kJ/mol.)

The compound carbon suboxide, C₃O₂, is a gas at room temperature. Use the data supplied to calculate the heat of formation of carbon suboxide. (Data: 2CO(g) + C(s)  C₃O₂(g) H° = 127.3 kJ/mol And: H_f^° of CO(g) = -110.5 kJ/mol)

Use the following data to calculate the standard heat (enthalpy) of formation, H°_f , of manganese(IV) oxide, MnO₂(s). 2MnO₂(s)  2MnO(s) + O₂(g) H = 264 kJ MnO₂(s) + Mn(s)  2MnO(s) H = -240 kJ

Which one of the following relationships is always correct?

a. Starting from the equation H = E + PV, show how the relationship H = q_p is derived. Clearly indicate any necessary assumptions or conditions. b. In one sentence, state in full what is meant by the equation: H = q_p.

A system expands from a volume of 1.00 L to 2.00 L against a constant external pressure of 1.00 atm. The work (w) done by the system, in J, is

E values obtained by bomb calorimetry can be converted to give accurate H values.

Ethanol, C₂H₅OH, is being promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the H°_rxn for the combustion of ethanol. (H°_f [C₂H₅OH(l)] = -277.7 kJ/mol; H°_f [CO₂(g)] = -393.5 kJ/mol; H°_f [H₂O(g)] = -241.8 kJ/mol)

H does not depend on the path of a reaction, but E does.

a. A gas sample absorbs 53 kJ of heat and does 18 kJ of work. Calculate the change in its internal energy. b. A system expands against a constant pressure of 1.50 atm, from an initial volume of 1.00 L to a final volume of 10.0 L. Calculate the work (w) involved in this process, in kJ.

Diborane (B₂H₆) has been considered as a possible rocket fuel. Calculate H° for the reaction B₂H₆(g)  2B(s) + 3H₂(g) using the following data: O₂(g)  H₂O(g) -242

Starting from equations relating pressure to force and force to work, derive the relationship w = - PV, explaining the steps in your argument.

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g·K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132°C to 85°C.

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

The 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: Bonding, Structure, and Reactivity

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 the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Exam 6: Thermochemistry: Energy Flow and Chemical Change

A system which undergoes an adiabatic change and does work on the surroundings has

The specific heat capacity c of a metal is approximately related to its molar mass as follows: c × = 3R, where R is the universal gas constant, 8.314 J/molK. Use this relationship to identify the metal which has a specific heat capacity of 0.900 J/gK.

In which of the following processes is H = E ?

In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (Data: H2O(l)  H2O(g) H = 44.01 kJ/mol.)

The compound carbon suboxide, C3O2, is a gas at room temperature. Use the data supplied to calculate the heat of formation of carbon suboxide. (Data: 2CO(g) + C(s)  C3O2(g) H° = 127.3 kJ/mol And: Hf° of CO(g) = -110.5 kJ/mol)

Use the following data to calculate the standard heat (enthalpy) of formation, H°f , of manganese(IV) oxide, MnO2 (s). 2MnO2(s)  2MnO(s) + O2(g) H = 264 kJ MnO2(s) + Mn(s)  2MnO(s) H = -240 kJ

Which one of the following relationships is always correct?

a. Starting from the equation H = E + PV, show how the relationship H = qp is derived. Clearly indicate any necessary assumptions or conditions. b. In one sentence, state in full what is meant by the equation: H = qp.

A system expands from a volume of 1.00 L to 2.00 L against a constant external pressure of 1.00 atm. The work (w) done by the system, in J, is

E values obtained by bomb calorimetry can be converted to give accurate H values.

Ethanol, C2H5OH, is being promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the H°rxn for the combustion of ethanol. (H°f [C2H5OH(l)] = -277.7 kJ/mol; H°f [CO2(g)] = -393.5 kJ/mol; H°f [H2O(g)] = -241.8 kJ/mol)

H does not depend on the path of a reaction, but E does.

a. A gas sample absorbs 53 kJ of heat and does 18 kJ of work. Calculate the change in its internal energy. b. A system expands against a constant pressure of 1.50 atm, from an initial volume of 1.00 L to a final volume of 10.0 L. Calculate the work (w) involved in this process, in kJ.

Diborane (B2H6) has been considered as a possible rocket fuel. Calculate H° for the reaction B2H6(g)  2B(s) + 3H2(g) using the following data: O2(g)  H2O(g) -242

Starting from equations relating pressure to force and force to work, derive the relationship w = - PV, explaining the steps in your argument.

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g·K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132°C to 85°C.

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

The 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: Bonding, Structure, and Reactivity

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 the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (Data: H₂O(l)  H₂O(g) H = 44.01 kJ/mol.)

The compound carbon suboxide, C₃O₂, is a gas at room temperature. Use the data supplied to calculate the heat of formation of carbon suboxide. (Data: 2CO(g) + C(s)  C₃O₂(g) H° = 127.3 kJ/mol And: H_f^° of CO(g) = -110.5 kJ/mol)

Use the following data to calculate the standard heat (enthalpy) of formation, H°_f , of manganese(IV) oxide, MnO₂(s). 2MnO₂(s)  2MnO(s) + O₂(g) H = 264 kJ MnO₂(s) + Mn(s)  2MnO(s) H = -240 kJ

a. Starting from the equation H = E + PV, show how the relationship H = q_p is derived. Clearly indicate any necessary assumptions or conditions. b. In one sentence, state in full what is meant by the equation: H = q_p.

Ethanol, C₂H₅OH, is being promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the H°_rxn for the combustion of ethanol. (H°_f [C₂H₅OH(l)] = -277.7 kJ/mol; H°_f [CO₂(g)] = -393.5 kJ/mol; H°_f [H₂O(g)] = -241.8 kJ/mol)

Diborane (B₂H₆) has been considered as a possible rocket fuel. Calculate H° for the reaction B₂H₆(g)  2B(s) + 3H₂(g) using the following data: O₂(g)  H₂O(g) -242