Question 1

When a system ________,ΔE is always negative.

Accepted Answer

A) absorbs heat and does work 
B) gives off heat and does work 
C) absorbs heat and has work done on it 
D) gives off heat and has work done on it 
E) None of the above is always negative. 
A) absorbs heat and does work 
B) gives off heat and does work 
C) absorbs heat and has work done on it 
D) gives off heat and has work done on it 
E) None of the above is always negative.

Question 2

The value of ΔH° for the reaction below is -336 kJ.Calculate the heat (kJ)released to the surroundings when 23.0 g of HCl is formed. CH4 (g)+ 3Cl2 (g)→ CHCl3 (l)+ 3HCl (g)

Accepted Answer

A) 177 kJ 
B) 2.57 × 103 kJ 
C) 70.7 kJ 
D) 211 kJ 
E) -336 kJ 
A) 177 kJ 
B) 2.57 × 103 kJ 
C) 70.7 kJ 
D) 211 kJ 
E) -336 kJ

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

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

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 5

Which one of the following is an exothermic process?

Accepted Answer

A) ice melting 
B) water evaporating 
C) boiling soup 
D) condensation of water vapor 
E) Ammonium thiocyanate and barium hydroxide are mixed at 25 °C: the temperature drops. 
A) ice melting 
B) water evaporating 
C) boiling soup 
D) condensation of water vapor 
E) Ammonium thiocyanate and barium hydroxide are mixed at 25 °C: the temperature drops.

Question 6

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 7

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 8

The change in the internal energy of a system that releases 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) -1.91 × 107 
D) 10,155 
E) 5,155 
A) -10,155 
B) -5,155 
C) -1.91 × 107 
D) 10,155 
E) 5,155

Question 9

The ΔHvap of water is 40.7 kJ at 100 °C.How much liquid water in grams can be converted to vapor if 5950 J of heat are absorbed?

Accepted Answer

Question 10

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 11

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

Question 12

The value of ΔH° for the reaction below is +128.1 kJ: CH3OH (l)→ CO (g)+ 2H2 (g)
How much heat is consumed when 87.1 g of hydrogen gas is formed?

Accepted Answer

A) 2.76 × 103 kJ 
B) 5.52 × 103 kJ 
C) -5.52 × 103 kJ 
D) -2.76 × 103 kJ 
E) -128.1 kJ 
A) 2.76 × 103 kJ 
B) 5.52 × 103 kJ 
C) -5.52 × 103 kJ 
D) -2.76 × 103 kJ 
E) -128.1 kJ

Question 13

The ________ of a reaction is the enthalpy change when all reactants and products are at 1 atm pressure and a specific temperature.

Accepted Answer

standard e

Question 14

What is the molar heat capacity (in J/mol-K)of liquid bromine? The specific heat of liquid bromine is 0.226 J/g-K.

Accepted Answer

A) 36.1 J/mol-K 
B) 707 J/mol-K 
C) 18.1 J/mol-K 
D) 9.05 J/mol-K 
E) 0.226 J/mol-K 
A) 36.1 J/mol-K 
B) 707 J/mol-K 
C) 18.1 J/mol-K 
D) 9.05 J/mol-K 
E) 0.226 J/mol-K

Question 15

The ΔHvap of water is 40.7 kJ at 100 °C.How much heat energy is required to convert 15.0 grams of liquid water to vapor.

Accepted Answer

Question 16

The value of ΔH° for the reaction below is -72 kJ. ________ kJ of heat are released when 5.5 mol of HBr is formed in this reaction. H2 (g)+ Br2 (g)→ 2HBr (g)

Accepted Answer

A) 144 
B) 72 
C) 0.44 
D) 198 
E) -72 
A) 144 
B) 72 
C) 0.44 
D) 198 
E) -72

Question 17

The molar heat capacity of an unknown substance is 92.1 J/mol-K.If the unknown has a molar mass of 118 g/mol,what is the specific heat (J/g-K)of this substance?

Accepted Answer

A) 1.28 
B) -92.1 
C) 1.09 × 104 
D) 0.781 
E) 92.1 
A) 1.28 
B) -92.1 
C) 1.09 × 104 
D) 0.781 
E) 92.1

Question 18

The value of ΔH° for the reaction below is -6535 kJ. ________ kJ of heat are released in the combustion of 16.0 g of     (l)?
2C6H6 (l)+ 15O2 (g)→ 12CO2 (g)+ 6H2O (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 19

The primary component of natural gas is methane.

Accepted Answer

A) True 
 B)False

Question 20

________ is defined as the energy used to move an object against a force.

Accepted Answer

The answer of ________ is defined as the energy used...

Exam 5: Thermochemistry

When a system ________,ΔE is always negative.

The value of ΔH° for the reaction below is -336 kJ.Calculate the heat (kJ)released to the surroundings when 23.0 g of HCl is formed. CH4 (g)+ 3Cl2 (g)→ CHCl3 (l)+ 3HCl (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

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

Which one of the following is an exothermic process?

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 BaO (s)is produced?

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

The ΔHvap of water is 40.7 kJ at 100 °C.How much liquid water in grams can be converted to vapor if 5950 J of heat are absorbed?

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 value of ΔH° for the reaction below is +128.1 kJ: CH3OH (l)→ CO (g)+ 2H2 (g) How much heat is consumed when 87.1 g of hydrogen gas is formed?

The ________ of a reaction is the enthalpy change when all reactants and products are at 1 atm pressure and a specific temperature.

What is the molar heat capacity (in J/mol-K)of liquid bromine? The specific heat of liquid bromine is 0.226 J/g-K.

The ΔHvap of water is 40.7 kJ at 100 °C.How much heat energy is required to convert 15.0 grams of liquid water to vapor.

The value of ΔH° for the reaction below is -72 kJ. ________ kJ of heat are released when 5.5 mol of HBr is formed in this reaction. H2 (g)+ Br2 (g)→ 2HBr (g)

The molar heat capacity of an unknown substance is 92.1 J/mol-K.If the unknown has a molar mass of 118 g/mol,what is the specific heat (J/g-K)of this substance?

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

The primary component of natural gas is methane.

________ is defined as the energy used to move an object against a force.

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 -336 kJ.Calculate the heat (kJ)released to the surroundings when 23.0 g of HCl is formed. CH₄ (g)+ 3Cl₂ (g)→ CHCl₃ (l)+ 3HCl (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

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?

The ΔH_vapof water is 40.7 kJ at 100 °C.How much liquid water in grams can be converted to vapor if 5950 J of heat are absorbed?

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 value of ΔH° for the reaction below is +128.1 kJ: CH₃OH (l)→ CO (g)+ 2H₂ (g) How much heat is consumed when 87.1 g of hydrogen gas is formed?

The ΔH_vapof water is 40.7 kJ at 100 °C.How much heat energy is required to convert 15.0 grams of liquid water to vapor.

The value of ΔH° for the reaction below is -72 kJ. ________ kJ of heat are released when 5.5 mol of HBr is formed in this reaction. H₂ (g)+ Br₂ (g)→ 2HBr (g)

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