Question 1

The value of ΔH° for the reaction below is -72 kJ. ________ kJ of heat are released when 80.9 grams of HBr is formed in this reaction. H2 (g) + Br2 (g) → 2HBr (g)

Accepted Answer

A) 144 
B) 72 
C) 0.44 
D) 36 
E) -72 
A) 144 
B) 72 
C) 0.44 
D) 36 
E) -72

Question 2

The kinetic energy of a 7.3 kg steel ball traveling at 18.0 m/s is ________ J.

Accepted Answer

A) 1.2 × 103 
B) 66 
C) 2.4 × 103 
D) 1.3 × 102 
E) 7.3 
A) 1.2 × 103 
B) 66 
C) 2.4 × 103 
D) 1.3 × 102 
E) 7.3

Question 3

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 Ba (s)reacts completely with oxygen to form BaO (s)?

Accepted Answer

A) 96.3 kJ 
B) 26.3 kJ 
C) 46.4 kJ 
D) 23.2 kJ 
E) 193 kJ 
A) 96.3 kJ 
B) 26.3 kJ 
C) 46.4 kJ 
D) 23.2 kJ 
E) 193 kJ

Question 4

The kinetic energy of a 23.2-g object moving at a speed of 98.7 m/s is ________ J.

Accepted Answer

A) 145 
B) 113 
C) 1450 
D) 0.950 
E) 113000 
A) 145 
B) 113 
C) 1450 
D) 0.950 
E) 113000

Question 5

A chemical reaction that absorbs heat from 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 6

Given the data in the table below, ΔH° for the reaction 2CO (g) + O2 (g) → 2CO2 (g)
Is ________ kJ.

Accepted Answer

A) -566.4 
B) -283.2 
C) 283.2 
D) -677.0 
E) The ΔH°f of O2 (g)is needed for the calculation. 
A) -566.4 
B) -283.2 
C) 283.2 
D) -677.0 
E) The ΔH°f of O2 (g)is needed for the calculation.

Question 7

Petroleum is a liquid composed of hundreds of compounds.

Accepted Answer

A) True 
 B)False

Question 8

The value of ΔH° for the reaction below is -6535 kJ. ________ kJ of heat are released in the combustion of 16.0 g of C6H6 (l)? 2C6H6 (l) + 15O2 (g) → 12CO2 (g) + 6 H2O (l)

Accepted Answer

A) 1.34 × 103 
B) 5.23 × 104 
C) 669 
D) 2.68 × 103 
E) -6535 
A) 1.34 × 103 
B) 5.23 × 104 
C) 669 
D) 2.68 × 103 
E) -6535

Question 9

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

Accepted Answer

A) H2 (g) + 1/2 O2 (g) → H2O (l) 
B) H2 (g) + O2 (g) → H2O2 (l) 
C) 2C (s, graphite) + 2H2 (g) → C2H4 (g) 
D) 1/2 N2 (g) + O2 (g) → NO2 (g) 
E) all of the above 
A) H2 (g) + 1/2 O2 (g) → H2O (l) 
B) H2 (g) + O2 (g) → H2O2 (l) 
C) 2C (s, graphite) + 2H2 (g) → C2H4 (g) 
D) 1/2 N2 (g) + O2 (g) → NO2 (g) 
E) all of the above

Question 10

The temperature of a 24.3 g sample of gold increases from 23.7 °C to 31.5 °C. If the specific heat of gold is 0.129 J/g-K, how many joules of heat are absorbed?

Accepted Answer

A) 24.5 J 
B) 0.0414 J 
C) -24.5 J 
D) 0.293 J 
E) 1.01 J 
A) 24.5 J 
B) 0.0414 J 
C) -24.5 J 
D) 0.293 J 
E) 1.01 J

Question 11

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

Accepted Answer

A) H2O (l) + 1/2 O2 (g) → H2O2 (l) 
B) N2 (g) + O2 (g) → 2NO (g) 
C) 2H2 (g) + O2 (g) → 2H2O (l) 
D) 2H2 (g) + O2 (g) → 2H2O (g) 
E) none of the above 
A) H2O (l) + 1/2 O2 (g) → H2O2 (l) 
B) N2 (g) + O2 (g) → 2NO (g) 
C) 2H2 (g) + O2 (g) → 2H2O (l) 
D) 2H2 (g) + O2 (g) → 2H2O (g) 
E) none of the above

Question 12

The value of ΔH° for the reaction below is -186 kJ. Calculate the heat (kJ)released from the reaction of 25 g of Cl2. H2 (g) + Cl2 (g) → 2HCl (g)

Accepted Answer

A) 66 kJ 
B) 5.3 × 102 kJ 
C) 33 kJ 
D) 47 kJ 
E) -186 kJ 
A) 66 kJ 
B) 5.3 × 102 kJ 
C) 33 kJ 
D) 47 kJ 
E) -186 kJ

Question 13

The temperature of a 35.1 g sample of iron increases from 24.5 °C to 31.8 °C. If the specific heat of iron is 0.450 J/g-K, how many joules of heat are absorbed?

Accepted Answer

A) 115 J 
B) 0.0936 J 
C) -115 J 
D) 0.722 J 
E) 3.29 J 
A) 115 J 
B) 0.0936 J 
C) -115 J 
D) 0.722 J 
E) 3.29 J

Question 14

The temperature of a 15-g sample of lead metal increases from 22 °C to 37 °C upon the addition of 29.0 J of heat. The specific heat capacity of the lead is ________ J/g-K.

Accepted Answer

A) 7.8 
B) 1.9 
C) 29 
D) 0.13 
E) -29 
A) 7.8 
B) 1.9 
C) 29 
D) 0.13 
E) -29

Question 15

Which one of the following conditions would always result in an increase in the internal energy of a system?

Accepted Answer

A) The system loses heat and does work on the surroundings. 
B) The system gains heat and does work on the surroundings. 
C) The system loses heat and has work done on it by the surroundings. 
D) The system gains heat and has work done on it by the surroundings. 
E) None of the above is correct. 
A) The system loses heat and does work on the surroundings. 
B) The system gains heat and does work on the surroundings. 
C) The system loses heat and has work done on it by the surroundings. 
D) The system gains heat and has work done on it by the surroundings. 
E) None of the above is correct.

Question 16

Given the data in the table below and ΔH°rxn for the reaction SO2Cl2 (g) + 2H2O (l) → H2SO4 (l) + 2HCl (g)ΔH° = -62 kJ
ΔH°f of HCl (g)is ________ kJ/mol.

Accepted Answer

A) -184 
B) 60 
C) -92 
D) 30 
E) Insufficient data are given. 
A) -184 
B) 60 
C) -92 
D) 30 
E) Insufficient data are given.

Question 17

Given the following reactions 2NO → N2 + O2 ΔH = -180 kJ
2NO + O2 → 2NO2 ΔH = -112 kJ
The enthalpy of the reaction of nitrogen with oxygen to produce nitrogen dioxide
N2 + 2O2 → 2NO2
Is ________ kJ.

Accepted Answer

A) 68 
B) -68 
C) -292 
D) 292 
E) -146 
A) 68 
B) -68 
C) -292 
D) 292 
E) -146

Question 18

The specific heat capacity of liquid water is 4.18 J/g-K. How many joules of heat are needed to raise the temperature of 7.25 g of water from 20.0 °C to 44.1 °C?

Accepted Answer

A) 41.8 J 
B) 730 J 
C) 1.94 × 103 J 
D) 2.39 × 10-2 J 
E) 66.8 J 
A) 41.8 J 
B) 730 J 
C) 1.94 × 103 J 
D) 2.39 × 10-2 J 
E) 66.8 J

Question 19

The average fuel value of sugars is 17 kJ/g. A 2.0 L pitcher of sweetened Kool-Aid® contains 400 g of sugar. What is the fuel value (in kJ)of a 500 mL serving of Kool-Aid®? (Assume that the sugar is the only fuel source.)

Accepted Answer

A) 4.2 × 104 kJ 
B) 1.7 × 103 kJ 
C) 1.7 × 106 kJ 
D) 1.7 × 102 kJ 
E) 17 kJ 
A) 4.2 × 104 kJ 
B) 1.7 × 103 kJ 
C) 1.7 × 106 kJ 
D) 1.7 × 102 kJ 
E) 17 kJ

Question 20

Calculate the kinetic energy in J of an electron moving at 6.00 × 106 m/s. The mass of an electron is 9.11 × 10-28 g.

Accepted Answer

A) 4.98 × 10-48 J 
B) 3.28 × 10-14 J 
C) 1.64 × 10-17 J 
D) 2.49 × 10-48 J 
E) 6.56 × 10-14 J 
A) 4.98 × 10-48 J 
B) 3.28 × 10-14 J 
C) 1.64 × 10-17 J 
D) 2.49 × 10-48 J 
E) 6.56 × 10-14 J

Exam 5: Thermochemistry

The value of ΔH° for the reaction below is -72 kJ. ________ kJ of heat are released when 80.9 grams of HBr is formed in this reaction. H2 (g) + Br2 (g) → 2HBr (g)

The kinetic energy of a 7.3 kg steel ball traveling at 18.0 m/s is ________ J.

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 Ba (s)reacts completely with oxygen to form BaO (s)?

The kinetic energy of a 23.2-g object moving at a speed of 98.7 m/s is ________ J.

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

Given the data in the table below, ΔH° for the reaction 2CO (g) + O2 (g) → 2CO2 (g) Is ________ kJ.

Petroleum is a liquid composed of hundreds of compounds.

The value of ΔH° for the reaction below is -6535 kJ. ________ kJ of heat are released in the combustion of 16.0 g of C6H6 (l)? 2C6H6 (l) + 15O2 (g) → 12CO2 (g) + 6 H2O (l)

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

The temperature of a 24.3 g sample of gold increases from 23.7 °C to 31.5 °C. If the specific heat of gold is 0.129 J/g-K, how many joules of heat are absorbed?

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

The value of ΔH° for the reaction below is -186 kJ. Calculate the heat (kJ)released from the reaction of 25 g of Cl2. H2 (g) + Cl2 (g) → 2HCl (g)

The temperature of a 35.1 g sample of iron increases from 24.5 °C to 31.8 °C. If the specific heat of iron is 0.450 J/g-K, how many joules of heat are absorbed?

The temperature of a 15-g sample of lead metal increases from 22 °C to 37 °C upon the addition of 29.0 J of heat. The specific heat capacity of the lead is ________ J/g-K.

Which one of the following conditions would always result in an increase in the internal energy of a system?

Given the data in the table below and ΔH°rxn for the reaction SO2Cl2 (g) + 2H2O (l) → H2SO4 (l) + 2HCl (g)ΔH° = -62 kJ ΔH°f of HCl (g)is ________ kJ/mol.

Given the following reactions 2NO → N2 + O2 ΔH = -180 kJ 2NO + O2 → 2NO2 ΔH = -112 kJ The enthalpy of the reaction of nitrogen with oxygen to produce nitrogen dioxide N2 + 2O2 → 2NO2 Is ________ kJ.

The specific heat capacity of liquid water is 4.18 J/g-K. How many joules of heat are needed to raise the temperature of 7.25 g of water from 20.0 °C to 44.1 °C?

The average fuel value of sugars is 17 kJ/g. A 2.0 L pitcher of sweetened Kool-Aid® contains 400 g of sugar. What is the fuel value (in kJ)of a 500 mL serving of Kool-Aid®? (Assume that the sugar is the only fuel source.)

Calculate the kinetic energy in J of an electron moving at 6.00 × 106 m/s. The mass of an electron is 9.11 × 10-28 g.

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

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The value of ΔH° for the reaction below is -72 kJ. ________ kJ of heat are released when 80.9 grams of HBr is formed in this reaction. H₂ (g) + Br₂ (g) → 2HBr (g)

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 Ba (s)reacts completely with oxygen to form BaO (s)?

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

Given the data in the table below, ΔH° for the reaction 2CO (g) + O₂ (g) → 2CO₂ (g) Is ________ kJ.

The value of ΔH° for the reaction below is -6535 kJ. ________ kJ of heat are released in the combustion of 16.0 g of C₆H₆ (l)? 2C₆H₆ (l) + 15O₂ (g) → 12CO₂ (g) + 6 H₂O (l)

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

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

The value of ΔH° for the reaction below is -186 kJ. Calculate the heat (kJ)released from the reaction of 25 g of Cl₂. H₂ (g) + Cl₂ (g) → 2HCl (g)

Given the data in the table below and ΔH°_rxn for the reaction SO₂Cl₂ (g) + 2H₂O (l) → H₂SO₄ (l) + 2HCl (g)ΔH° = -62 kJ ΔH°_f of HCl (g)is ________ kJ/mol.

Given the following reactions 2NO → N₂ + O₂ ΔH = -180 kJ 2NO + O₂ → 2NO₂ ΔH = -112 kJ The enthalpy of the reaction of nitrogen with oxygen to produce nitrogen dioxide N₂ + 2O₂ → 2NO₂ Is ________ kJ.

Calculate the kinetic energy in J of an electron moving at 6.00 × 10⁶ m/s. The mass of an electron is 9.11 × 10^-28g.