Question 1

When work is done on a system,w will be a ________ value.

Accepted Answer

A) positive 
B) negative 
C) very large 
D) very small 
E) There is not enough information given to determine the answer. 
A) positive 
B) negative 
C) very large 
D) very small 
E) There is not enough information given to determine the answer. A

Question 2

The value of ΔH° for the reaction below is -482 kJ.Calculate the heat (kJ)released to the surroundings when 10.0 g of CO (g)reacts completely. 2CO (g)+ O2 (g)→ 2CO2 (g)

Accepted Answer

A) 2410 kJ 
B) 172 kJ 
C) 86.0 kJ 
D) 482 kJ 
E) -482 kJ 
A) 2410 kJ 
B) 172 kJ 
C) 86.0 kJ 
D) 482 kJ 
E) -482 kJ C

Question 3

Given the data in the table below,ΔH°rxn for the reaction 3Cl2 (g)+ PH3 (g)→ PCl3 (g)+ 3HCl (g)
Is ________ kJ.

Accepted Answer

A) -385.77 
B) -570.37 
C) 570.37 
D) 385.77 
E) The ΔH°f of Cl2 (g)is needed for the calculation. 
A) -385.77 
B) -570.37 
C) 570.37 
D) 385.77 
E) The ΔH°f of Cl2 (g)is needed for the calculation. B

Question 4

Calculate the kinetic energy in joules of an automobile weighing 2135 lb and traveling at 55 mph.

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 5

The value of ΔE for a system that performs 19 kJ of work on its surroundings and loses   of heat is

Accepted Answer

A) -28 
B) 28 
C) 171 
D) 10 
E) -10 
A) -28 
B) 28 
C) 171 
D) 10 
E) -10

Question 6

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

Question 7

Work equals mass times distance.

Accepted Answer

A) True 
 B)False

Question 8

For the following reactions,the ΔH°rxn is NOT equal to ΔH°f for the product except for ________.

Accepted Answer

A) 2Ca (s)+ O2 (g)→ 2CaO (s) 
B) 3Mg (s)+ N2 (g)→ Mg3N2 (s) 
C) C2H2 (g)+ H2 (g)→   H4 (g) 
D) 2C (graphite)+ O2 (g)→ 2CO (g) 
E) C (diamond)+ O2 (g)→ CO2 (g) 
A) 2Ca (s)+ O2 (g)→ 2CaO (s) 
B) 3Mg (s)+ N2 (g)→ Mg3N2 (s) 
C) C2H2 (g)+ H2 (g)→   H4 (g) 
D) 2C (graphite)+ O2 (g)→ 2CO (g) 
E) C (diamond)+ O2 (g)→ CO2 (g)

Question 9

Energy units include watts,volts,and newtons.

Accepted Answer

A) True 
 B)False

Question 10

The value of ΔH° for the reaction below is +128.1 kJ: CH3OH (l)→ CO (g)+ 2H2 (g)
How many kJ of heat are consumed when 15.5 g of C   OH (l)decomposes as shown in the equation?

Accepted Answer

A) 0.48 kJ 
B) 62.0 kJ 
C) 1.3 × 102 kJ 
D) 32 kJ 
E) 8.3 kJ 
A) 0.48 kJ 
B) 62.0 kJ 
C) 1.3 × 102 kJ 
D) 32 kJ 
E) 8.3 kJ

Question 11

The value of ΔH° for the reaction below is -790 kJ.The enthalpy change accompanying the reaction of 0.95 g of S is ________ kJ. 2S (s)+ 3O2 (g)→ 2SO3 (g)

Accepted Answer

A) 23 
B) -23 
C) -12 
D) 12 
E) -790 
A) 23 
B) -23 
C) -12 
D) 12 
E) -790

Question 12

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 13

A sample of iron absorbs 81.0 J of heat,upon which the temperature of the sample increases from   to   If the specific heat of iron is 0.450 J/g-K,what is the mass (in grams)of the sample?

Accepted Answer

A) 21.2 g 
B) 4.29 g 
C) -21.2 g 
D) 0.0472 g 
E) 3.83 g 
A) 21.2 g 
B) 4.29 g 
C) -21.2 g 
D) 0.0472 g 
E) 3.83 g

Question 14

A ________ ΔH corresponds to an ________ process.

Accepted Answer

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

Question 15

The specific heat capacity of methane gas is 2.20 J/g-K.How many joules of heat are needed to raise the temperature of 7.25 g of methane from 22.0 °C to 57.0 °C?

Accepted Answer

A) 115 J 
B) 558 J 
C) 1.26 × 103 J 
D) 8.67 × 10-3 J 
E) 41.3 J 
A) 115 J 
B) 558 J 
C) 1.26 × 103 J 
D) 8.67 × 10-3 J 
E) 41.3 J

Question 16

Hydrogen gas and bromine gas react to form hydrogen bromide gas.How much heat (kJ)is released when 155 grams of HBr is formed in this reaction? ΔH° = -72 kJ.

Accepted Answer

A) 137 
B) 69 
C) -69 
D) -137 
E) 1.12 × 105 
A) 137 
B) 69 
C) -69 
D) -137 
E) 1.12 × 105

Question 17

The internal energy of a system is always increased by ________.

Accepted Answer

A) adding heat to the system 
B) having the system do work on the surroundings 
C) withdrawing heat from the system 
D) adding heat to the system and having the system do work on the surroundings 
E) a volume decompression 
A) adding heat to the system 
B) having the system do work on the surroundings 
C) withdrawing heat from the system 
D) adding heat to the system and having the system do work on the surroundings 
E) a volume decompression

Question 18

The units of heat capacity are ________.

Accepted Answer

A) K/J or °C/J 
B) J/K or J/°C 
C) J/g-K or J/g-°C 
D) J/mol 
E) g-K/J or g-°C/J 
A) K/J or °C/J 
B) J/K or J/°C 
C) J/g-K or J/g-°C 
D) J/mol 
E) g-K/J or g-°C/J

Question 19

The ΔE of a system that absorbs 12.4 J of heat and does 4.2 J of work on the surroundings is ________ J.

Accepted Answer

A) 16.6 
B) 12.4 
C) 4.2 
D) -16.6 
E) 8.2 
A) 16.6 
B) 12.4 
C) 4.2 
D) -16.6 
E) 8.2

Question 20

A sample of calcium carbonate [CaCO3 (s)] absorbs   of heat,upon which the temperature of the sample increases from   to   If the specific heat of calcium carbonate is   what is the mass (in grams)of the sample?

Accepted Answer

A) 7.6 g 
B) 5.1 g 
C) -7.6 g 
D) 0.13 g 
E) 5.3 g 
A) 7.6 g 
B) 5.1 g 
C) -7.6 g 
D) 0.13 g 
E) 5.3 g

Exam 5: Thermochemistry

When work is done on a system,w will be a ________ value.

The value of ΔH° for the reaction below is -482 kJ.Calculate the heat (kJ)released to the surroundings when 10.0 g of CO (g)reacts completely. 2CO (g)+ O2 (g)→ 2CO2 (g)

Given the data in the table below,ΔH°rxn for the reaction 3Cl2 (g)+ PH3 (g)→ PCl3 (g)+ 3HCl (g) Is ________ kJ.

Calculate the kinetic energy in joules of an automobile weighing 2135 lb and traveling at 55 mph.

The value of ΔE for a system that performs 19 kJ of work on its surroundings and loses of heat is

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.

Work equals mass times distance.

For the following reactions,the ΔH°rxn is NOT equal to ΔH°f for the product except for ________.

Energy units include watts,volts,and newtons.

The value of ΔH° for the reaction below is +128.1 kJ: CH3OH (l)→ CO (g)+ 2H2 (g) How many kJ of heat are consumed when 15.5 g of C OH (l)decomposes as shown in the equation?

The value of ΔH° for the reaction below is -790 kJ.The enthalpy change accompanying the reaction of 0.95 g of S is ________ kJ. 2S (s)+ 3O2 (g)→ 2SO3 (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.

A sample of iron absorbs 81.0 J of heat,upon which the temperature of the sample increases from to If the specific heat of iron is 0.450 J/g-K,what is the mass (in grams)of the sample?

A ________ ΔH corresponds to an ________ process.

The specific heat capacity of methane gas is 2.20 J/g-K.How many joules of heat are needed to raise the temperature of 7.25 g of methane from 22.0 °C to 57.0 °C?

Hydrogen gas and bromine gas react to form hydrogen bromide gas.How much heat (kJ)is released when 155 grams of HBr is formed in this reaction? ΔH° = -72 kJ.

The internal energy of a system is always increased by ________.

The units of heat capacity are ________.

The ΔE of a system that absorbs 12.4 J of heat and does 4.2 J of work on the surroundings is ________ J.

A sample of calcium carbonate [CaCO3 (s)] absorbs of heat,upon which the temperature of the sample increases from to If the specific heat of calcium carbonate is what is the mass (in grams)of the sample?

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Chemical Reactions and Reaction Stoichiometry

Reactions in Aqueous Solution

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 -482 kJ.Calculate the heat (kJ)released to the surroundings when 10.0 g of CO (g)reacts completely. 2CO (g)+ O₂(g)→ 2CO₂ (g)

Given the data in the table below,ΔH°_rxn for the reaction 3Cl₂ (g)+ PH₃ (g)→ PCl₃ (g)+ 3HCl (g) Is ________ kJ.

For the following reactions,the ΔH°_rxn is NOT equal to ΔH°_f for the product except for ________.

The value of ΔH° for the reaction below is +128.1 kJ: CH₃OH (l)→ CO (g)+ 2H₂ (g) How many kJ of heat are consumed when 15.5 g of C OH (l)decomposes as shown in the equation?

The value of ΔH° for the reaction below is -790 kJ.The enthalpy change accompanying the reaction of 0.95 g of S is ________ kJ. 2S (s)+ 3O₂ (g)→ 2SO₃ (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.

A ΔH corresponds to an process.

A sample of calcium carbonate [CaCO₃ (s)] absorbs of heat,upon which the temperature of the sample increases from to If the specific heat of calcium carbonate is what is the mass (in grams)of the sample?