Question 1

Given the data in the table below, ΔH°rxn for the reaction 4NH3 (g) + 5O2 (g) → 4NO (g) + 6H2O (l)
Is ________ kJ.

Accepted Answer

A) -1172 
B) -150 
C) -1540 
D) -1892 
E) The ΔH°f of O2 (g)is needed for the calculation. 
A) -1172 
B) -150 
C) -1540 
D) -1892 
E) The ΔH°f of O2 (g)is needed for the calculation. A

Question 2

The molar heat capacity of a compound with the formula C2H6 SO is 88.0 J/mol-K. The specific heat of this substance is ________ J/g-K.

Accepted Answer

A) 88.0 
B) 1.13 
C) 4.89 
D) 6.88 × 103 
E) -88.0 
A) 88.0 
B) 1.13 
C) 4.89 
D) 6.88 × 103 
E) -88.0 B

Question 3

Which of the following is a statement of Hess's law?

Accepted Answer

A) If a reaction is carried out in a series of steps, the ΔH for the reaction will equal the sum of the enthalpy changes for the individual steps. 
B) If a reaction is carried out in a series of steps, the ΔH for the reaction will equal the product of the enthalpy changes for the individual steps. 
C) The ΔH for a process in the forward direction is equal in magnitude and opposite in sign to the ΔH for the process in the reverse direction. 
D) The ΔH for a process in the forward direction is equal to the ΔH for the process in the reverse direction. 
E) The ΔH of a reaction depends on the physical states of the reactants and products. 
A) If a reaction is carried out in a series of steps, the ΔH for the reaction will equal the sum of the enthalpy changes for the individual steps. 
B) If a reaction is carried out in a series of steps, the ΔH for the reaction will equal the product of the enthalpy changes for the individual steps. 
C) The ΔH for a process in the forward direction is equal in magnitude and opposite in sign to the ΔH for the process in the reverse direction. 
D) The ΔH for a process in the forward direction is equal to the ΔH for the process in the reverse direction. 
E) The ΔH of a reaction depends on the physical states of the reactants and products. A

Question 4

A 100-watt electric incandescent light bulb consumes ________ J of energy in 24 hours. [1 Watt (W)= 1 J/sec]

Accepted Answer

A) 2.40 × 103 
B) 8.64 × 103 
C) 4.17 
D) 2.10 × 103 
E)  8.64 × 106 
A) 2.40 × 103 
B) 8.64 × 103 
C) 4.17 
D) 2.10 × 103 
E)  8.64 × 106

Question 5

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O2 (g) → 2BaO (s)
How many kJ of heat are released when 15.75 g of Ba (s)reacts completely with oxygen to form BaO (s)?

Accepted Answer

A) 20.8 kJ 
B) 63.5 kJ 
C) 114 kJ 
D) 70.3 kJ 
E) 35.1 kJ 
A) 20.8 kJ 
B) 63.5 kJ 
C) 114 kJ 
D) 70.3 kJ 
E) 35.1 kJ

Question 6

Given the data in the table below, ΔH°rxn for the reaction SO3 (g) + H2O (l) → H2SO4 (l)
Is ________ kJ.

Accepted Answer

A) -132 
B) 1496 
C) 704 
D) -704 
E) -2.16 × 103 
A) -132 
B) 1496 
C) 704 
D) -704 
E) -2.16 × 103

Question 7

A 22.9 g sample of iron absorbs 155 J of heat, upon which the temperature of the sample increases from 23.9 °C to 38.9 °C. What is the specific heat of iron?

Accepted Answer

A) 0.451 J/g-K 
B) -0.451 J/g-K 
C) 237 J/g-K 
D) 102 J/g-K 
E) 53,200 J/g-K 
A) 0.451 J/g-K 
B) -0.451 J/g-K 
C) 237 J/g-K 
D) 102 J/g-K 
E) 53,200 J/g-K

Question 8

A ________ ΔH corresponds to an ________ process.

Accepted Answer

A) negative, endothermic 
B) negative, exothermic 
C) positive, exothermic 
D) zero, exothermic 
E) zero, endothermic 
A) negative, endothermic 
B) negative, exothermic 
C) positive, exothermic 
D) zero, exothermic 
E) zero, endothermic

Question 9

Given the following reactions H2O (l) → H2O (g)ΔH = 44.01 kJ
2H2 (g) + O2 (g) → 2H2O (g)ΔH = -483.64 kJ
The enthalpy for the decomposition of liquid water into gaseous hydrogen and oxygen
2H2O (l) → 2H2 (g) + O2 (g)
Is ________ kJ.

Accepted Answer

A) -395.62 
B) -527.65 
C) 439.63 
D) 571.66 
E) 527.65 
A) -395.62 
B) -527.65 
C) 439.63 
D) 571.66 
E) 527.65

Question 10

The internal energy of a system ________.

Accepted Answer

A) is the sum of the kinetic energy of all of its components 
B) is the sum of the rotational, vibrational, and translational energies of all of its components 
C) refers only to the energies of the nuclei of the atoms of the component molecules 
D) is the sum of the potential and kinetic energies of the components 
E) none of the above 
A) is the sum of the kinetic energy of all of its components 
B) is the sum of the rotational, vibrational, and translational energies of all of its components 
C) refers only to the energies of the nuclei of the atoms of the component molecules 
D) is the sum of the potential and kinetic energies of the components 
E) none of the above

Question 11

The change in the internal energy of a system that absorbs 2,500 J of heat and that does 7,655 J of work on the surroundings is ________ J.

Accepted Answer

A) 10,155 
B) 5,155 
C) -5,155 
D) -10,155 
E) 1.91 ×   
A) 10,155 
B) 5,155 
C) -5,155 
D) -10,155 
E) 1.91 ×

Question 12

The combustion of titanium with oxygen produces titanium dioxide: Ti (s)+ O2 (g) → TiO2 (s)
When 0.610 g of titanium is combusted in a bomb calorimeter, the temperature of the calorimeter increases from 25.00 °C to 50.50 °C. In a separate experiment, the heat capacity of the calorimeter is measured to be 9.84 kJ/K. The heat of reaction for the combustion of a mole of Ti in this calorimeter is ________ kJ/mol.

Accepted Answer

A) 2.09 
B) 4.14 
C) -311 
D) -0.154 
E) -1.98 × 104 
A) 2.09 
B) 4.14 
C) -311 
D) -0.154 
E) -1.98 × 104

Question 13

For which one of the following reactions is the value of ΔH°rxn equal to ΔH°f for the product?

Accepted Answer

A) 2Ca (s) + O2 (g) → 2CaO (s) 
B) C2H2 (g) + H2 (g) → C2H4 (g) 
C) 2C (graphite) + O2 (g) → 2CO (g) 
D) 3Mg (s) + N2 (g) → Mg3N2 (s) 
E) C (diamond) + O2 (g) → CO2 (g) 
A) 2Ca (s) + O2 (g) → 2CaO (s) 
B) C2H2 (g) + H2 (g) → C2H4 (g) 
C) 2C (graphite) + O2 (g) → 2CO (g) 
D) 3Mg (s) + N2 (g) → Mg3N2 (s) 
E) C (diamond) + O2 (g) → CO2 (g)

Question 14

Calculate the work (kJ)done during a reaction in which the internal volume expands from 19 L to 48 L against an outside pressure of 2.5 atm.

Accepted Answer

A) -7.3 kJ 
B) 17 kJ 
C) 7.3 kJ 
D) -17 kJ 
E) 0 kJ; No work is done. 
A) -7.3 kJ 
B) 17 kJ 
C) 7.3 kJ 
D) -17 kJ 
E) 0 kJ; No work is done.

Question 15

A chemical reaction that releases heat to the surroundings is said to be ________ and has a ________ ΔH at constant pressure.

Accepted Answer

A) endothermic, positive 
B) endothermic, negative 
C) exothermic, negative 
D) exothermic, positive 
E) exothermic, neutral 
A) endothermic, positive 
B) endothermic, negative 
C) exothermic, negative 
D) exothermic, positive 
E) exothermic, neutral

Question 16

Calculate the kinetic energy in joules of an automobile weighing 2135 lb and traveling at 55 mph. (1 mile = 1.6093 km, 1lb = 453.59 g).

Accepted Answer

A) 1.2 × 104 J 
B) 2.9 × 105 J 
C) 5.9 × 105 J 
D) 3.2 × 106 J 
E) 3.2 × 10-6 J 
A) 1.2 × 104 J 
B) 2.9 × 105 J 
C) 5.9 × 105 J 
D) 3.2 × 106 J 
E) 3.2 × 10-6 J

Question 17

Which one of the following is an endothermic process?

Accepted Answer

A) ice melting 
B) water freezing 
C) boiling soup 
D) Hydrochloric acid and barium hydroxide are mixed at 25 °C: the temperature increases. 
E) Both A and C 
A) ice melting 
B) water freezing 
C) boiling soup 
D) Hydrochloric acid and barium hydroxide are mixed at 25 °C: the temperature increases. 
E) Both A and C

Question 18

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O2 (g) → 2BaO (s)
How many kJ of heat are released when 5.75 g of BaO (s)is produced?

Accepted Answer

A) 56.9 kJ 
B) 23.2 kJ 
C) 20.8 kJ 
D) 193 kJ 
E) 96.3 kJ 
A) 56.9 kJ 
B) 23.2 kJ 
C) 20.8 kJ 
D) 193 kJ 
E) 96.3 kJ

Question 19

Given the data in the table below, ΔH°rxn for the reaction C2H5OH (l) + O2 (g) → CH3CO2H (l) + H2O (l)
Is ________ kJ.

Accepted Answer

A) -79.0 
B) -1048.0 
C) -476.4 
D) -492.6 
E) The value of ΔH°f of O2 (g)is required for the calculation. 
A) -79.0 
B) -1048.0 
C) -476.4 
D) -492.6 
E) The value of ΔH°f of O2 (g)is required for the calculation.

Question 20

Calculate the value of ΔE in joules for a system that loses 115 J of heat and has 150 J of work performed on it by the surroundings.

Accepted Answer

A) -115 J 
B) -35 J 
C) +35 J 
D) +265 J 
E) -265 J 
A) -115 J 
B) -35 J 
C) +35 J 
D) +265 J 
E) -265 J

Exam 5: Thermochemistry

Given the data in the table below, ΔH°rxn for the reaction 4NH3 (g) + 5O2 (g) → 4NO (g) + 6H2O (l) Is ________ kJ.

The molar heat capacity of a compound with the formula C2H6 SO is 88.0 J/mol-K. The specific heat of this substance is ________ J/g-K.

Which of the following is a statement of Hess's law?

A 100-watt electric incandescent light bulb consumes ________ J of energy in 24 hours. [1 Watt (W)= 1 J/sec]

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O2 (g) → 2BaO (s) How many kJ of heat are released when 15.75 g of Ba (s)reacts completely with oxygen to form BaO (s)?

Given the data in the table below, ΔH°rxn for the reaction SO3 (g) + H2O (l) → H2SO4 (l) Is ________ kJ.

A 22.9 g sample of iron absorbs 155 J of heat, upon which the temperature of the sample increases from 23.9 °C to 38.9 °C. What is the specific heat of iron?

A ________ ΔH corresponds to an ________ process.

Given the following reactions H2O (l) → H2O (g)ΔH = 44.01 kJ 2H2 (g) + O2 (g) → 2H2O (g)ΔH = -483.64 kJ The enthalpy for the decomposition of liquid water into gaseous hydrogen and oxygen 2H2O (l) → 2H2 (g) + O2 (g) Is ________ kJ.

The internal energy of a system ________.

The change in the internal energy of a system that absorbs 2,500 J of heat and that does 7,655 J of work on the surroundings is ________ J.

For which one of the following reactions is the value of ΔH°rxn equal to ΔH°f for the product?

Calculate the work (kJ)done during a reaction in which the internal volume expands from 19 L to 48 L against an outside pressure of 2.5 atm.

A chemical reaction that releases heat to the surroundings is said to be ________ and has a ________ ΔH at constant pressure.

Calculate the kinetic energy in joules of an automobile weighing 2135 lb and traveling at 55 mph. (1 mile = 1.6093 km, 1lb = 453.59 g).

Which one of the following is an endothermic process?

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O2 (g) → 2BaO (s) How many kJ of heat are released when 5.75 g of BaO (s)is produced?

Given the data in the table below, ΔH°rxn for the reaction C2H5OH (l) + O2 (g) → CH3CO2H (l) + H2O (l) Is ________ kJ.

Calculate the value of ΔE in joules for a system that loses 115 J of heat and has 150 J of work performed on it by the surroundings.

Introduction: Matter and Measurement

Atoms, Molecules, and Ions

Stoichiometry: Calculations With Chemical Formulas and Equations

Aqueous Reactions and Solution Stoichiometry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

Given the data in the table below, ΔH°_rxn for the reaction 4NH₃ (g) + 5O₂ (g) → 4NO (g) + 6H₂O (l) Is ________ kJ.

The molar heat capacity of a compound with the formula C₂H₆ SO is 88.0 J/mol-K. The specific heat of this substance is ________ J/g-K.

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O₂ (g) → 2BaO (s) How many kJ of heat are released when 15.75 g of Ba (s)reacts completely with oxygen to form BaO (s)?

Given the data in the table below, ΔH°_rxn for the reaction SO₃ (g) + H₂O (l) → H₂SO₄ (l) Is ________ kJ.

A ΔH corresponds to an process.

Given the following reactions H₂O (l) → H₂O (g)ΔH = 44.01 kJ 2H₂ (g) + O₂ (g) → 2H₂O (g)ΔH = -483.64 kJ The enthalpy for the decomposition of liquid water into gaseous hydrogen and oxygen 2H₂O (l) → 2H₂ (g) + O₂ (g) Is ________ kJ.

For which one of the following reactions is the value of ΔH°_rxn equal to ΔH°_f for the product?

A chemical reaction that releases heat to the surroundings is said to be and has a ΔH at constant pressure.

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O₂ (g) → 2BaO (s) How many kJ of heat are released when 5.75 g of BaO (s)is produced?

Given the data in the table below, ΔH°_rxn for the reaction C₂H₅OH (l) + O₂ (g) → CH₃CO₂H (l) + H₂O (l) Is ________ kJ.