Question 1

Match the following.

-energy associated with the position of an object

Accepted Answer

A) kinetic energy 
B) potential energy 
C) chemical energy 
D) thermal energy 
A) kinetic energy 
B) potential energy 
C) chemical energy 
D) thermal energy

Question 2

A piece of gold with a mass of 21.0 g was heated to 100.0 °C and placed inside a coffee cup calorimeter. The temperature of the water inside the calorimeter increased from 23.8 °C to 25.5 °C. The specific heat capacity of water is 4.184 J g-1 °C-1 and the specific heat capacity of gold is 0.129 J g-1 °C-1. Calculate the mass of water contained inside the calorimeter.

Accepted Answer

A) 28.4 g 
B) 16.0 g 
C) 21.0 g 
D) 39.5 g 
E) 32.9 g 
A) 28.4 g 
B) 16.0 g 
C) 21.0 g 
D) 39.5 g 
E) 32.9 g

Question 3

Define heat capacity.

Accepted Answer

A) the quantity of heat required to raise the temperature of 1 mol of a substance by 1 °C 
B) the quantity of heat required to change a system's temperature by 1 °C 
C) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °C 
D) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °F 
E) the quantity of heat required to raise the temperature of 1 L of a substance by 1 °C 
A) the quantity of heat required to raise the temperature of 1 mol of a substance by 1 °C 
B) the quantity of heat required to change a system's temperature by 1 °C 
C) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °C 
D) the quantity of heat required to raise the temperature of 1 g of a substance by 1 °F 
E) the quantity of heat required to raise the temperature of 1 L of a substance by 1 °C

Question 4

A 5.00 g sample of copper metal at 25.0 °C is heated by the addition of 96.0 J of energy. The final temperature of the copper is ________°C. The specific heat capacity of copper is 0.38 J g-1 K-1.

Accepted Answer

A) 32.3 
B) 25.0 
C) 25.5 
D) 75.5 
E) 50.5 
A) 32.3 
B) 25.0 
C) 25.5 
D) 75.5 
E) 50.5

Question 5

Use the ΔfH° and ΔrH° information provided to calculate ΔfH° for IF: ΔfH° (kJ mol-1) IF7(g)+ I2(g)→ IF5(g)+ 2IF(g)ΔrH° = -89 kJ
IF7(g) -941
IF5(g) -840

Accepted Answer

A) 101 kJ mol-1 
B) -146 kJ mol-1 
C) -190. kJ mol-1 
D) -95 kJ mol-1 
E) 24 kJ mol-1 
A) 101 kJ mol-1 
B) -146 kJ mol-1 
C) -190. kJ mol-1 
D) -95 kJ mol-1 
E) 24 kJ mol-1

Question 6

Identify the units of specific heat capacity.

Accepted Answer

A) °C-1 
B) J g-1 °C-1 
C) J mol-1 °C-1 
D) g °C-1 
E) mol °C-1 
A) °C-1 
B) J g-1 °C-1 
C) J mol-1 °C-1 
D) g °C-1 
E) mol °C-1

Question 7

Calculate the change in internal energy (ΔU)for a system that is giving off 25.0 kJ of heat and is changing from 12.00 L to 6.00 L in volume at 1.50 bar. (Remember that 100 J = 1 L bar)

Accepted Answer

A) +25.9 kJ 
B) -16.0 kJ 
C) -25.9 kJ 
D) -24.1 kJ 
E) 937 kJ 
A) +25.9 kJ 
B) -16.0 kJ 
C) -25.9 kJ 
D) -24.1 kJ 
E) 937 kJ

Question 8

Calculate the final temperature of 82.1 g of molecular hydrogen (specific heat capacity = 14.304 J g-1 °C-1)initially at 5.48 °C that absorbs 57 kJ of energy from the surroundings.

Accepted Answer

A) 14 °C 
B) 24 °C 
C) 34 °C 
D) 44 °C 
E) 54 °C 
A) 14 °C 
B) 24 °C 
C) 34 °C 
D) 44 °C 
E) 54 °C

Question 9

Which of the following is NOT a standard state?

Accepted Answer

A) for a solid, it is 25 °F 
B) for a liquid, it is 25 °C 
C) for a solution, it is 1 bar 
D) for a solution, it is 1 mol L-1 
E) for a liquid, it is 1 bar 
A) for a solid, it is 25 °F 
B) for a liquid, it is 25 °C 
C) for a solution, it is 1 bar 
D) for a solution, it is 1 mol L-1 
E) for a liquid, it is 1 bar

Question 10

A bomb calorimeter with a heat capacity of 13.9 kJ °C-1 has an initial temperature of 21.9 °C. If 5.00 g of propanal (C3H6O, molar mass = 58.0791 g mol-1, $\Delta$rU = -1822.7 kJ mol-1 for combustion)is combusted, calculate the final temperature of the calorimeter.

Accepted Answer

A) 26.1 °C 
B) 16.7 °C 
C) 33.2 °C 
D) 43.1 °C 
E) 34.0 °C 
A) 26.1 °C 
B) 16.7 °C 
C) 33.2 °C 
D) 43.1 °C 
E) 34.0 °C

Question 11

Identify the greatest source of energy worldwide.

Accepted Answer

A) petroleum 
B) natural gas 
C) wood 
D) coal 
E) nuclear power 
A) petroleum 
B) natural gas 
C) wood 
D) coal 
E) nuclear power

Question 12

Use the ΔfH° information provided to calculate ΔrH° for the following: ΔfH° (kJ mol-1)  SO2Cl2 (g)+ 2H2O(l)→ 2HCl(g)+ H2SO4(l)ΔrH° = ?
SO2Cl2(g)-364
H2O(l) -286
HCl(g) 92
H2SO4(l)-814

Accepted Answer

A) -256 kJ mol-1 
B) +161 kJ mol-1 
C) -62 kJ mol-1 
D) +800. kJ mol-1 
E) -422 kJ mol-1 
A) -256 kJ mol-1 
B) +161 kJ mol-1 
C) -62 kJ mol-1 
D) +800. kJ mol-1 
E) -422 kJ mol-1

Question 13

Identify a substance that is NOT in its standard state.

Accepted Answer

A) CO 
B) Ca 
C) H2 
D) O2 
E) Ne 
A) CO 
B) Ca 
C) H2 
D) O2 
E) Ne

Question 14

Identify the units of heat capacity.

Accepted Answer

A) J °C-1 
B) J g-1 °C-1 
C) J mol-1 °C-1 
D) g °C-1 
E) mol °C-1 
A) J °C-1 
B) J g-1 °C-1 
C) J mol-1 °C-1 
D) g °C-1 
E) mol °C-1

Question 15

At constant pressure, the combustion of 20.0 g of C2H6(g)releases 1036 kJ of heat. What is ΔH for the reaction given below? 2C2H6(g)+ 7O2(g)→ 4CO2(g)+ 6H2O(l)

Accepted Answer

A) -173 kJ mol-1 
B) -779 kJ mol-1 
C) -1560 kJ mol-1 
D) -3120 kJ mol-1 
A) -173 kJ mol-1 
B) -779 kJ mol-1 
C) -1560 kJ mol-1 
D) -3120 kJ mol-1

Question 16

At 1.0133 bar, the heat of sublimation of gallium is 277 kJ mol-1 and the heat of vaporization is 271 kJ mol-1. To the correct number of significant figures, how much heat is required to melt 5.50 mol of gallium at 1.0133 bar?

Accepted Answer

A) 6 kJ 
B) 33 kJ 
C) 244 kJ 
D) 274 kJ 
A) 6 kJ 
B) 33 kJ 
C) 244 kJ 
D) 274 kJ

Question 17

According to the following thermochemical equation, what mass of H2O (in g)must form to produce 975 kJ of energy? SiO2(s)+ 4HF(g)→ SiF4(g)+ 2H2O(l)ΔrH° = -184 kJ

Accepted Answer

A) 68.0 g 
B) 102 g 
C) 54.1 g 
D) 191 g 
E) 95.5 g 
A) 68.0 g 
B) 102 g 
C) 54.1 g 
D) 191 g 
E) 95.5 g

Question 18

Write the reaction illustrating ΔfH° of CaCO3 and draw the enthalpy diagram showing the relative positions of the reactants and products if it is an exothermic reaction.

Accepted Answer

Ca(s)+ C(s, graphite)+ 3/2 O₂(g

Question 19

10.618 g of an unknown salt is dissolved in a coffee cup calorimeter that contains 50.0 mL of water. The measured temperature decreased from 23.8 °C to 22.7 °C. Identify the unknown salt. The specific heat of water is 4.184 J g-1 °C-1, and assume the density of the solution is 1.00 g mL-1.

Accepted Answer

A) NaF, ΔrH = 0.91 kJ mol-1 
B) NaBr, ΔrH = -0.60 kJ mol-1 
C) NaNO3, ΔrH = 20.50 kJ mol-1 
D) LiNO3, ΔrH = -2.51 kJ mol-1 
E) LiBr∙2H2O, ΔrH = -23.26 kJ mol-1 
A) NaF, ΔrH = 0.91 kJ mol-1 
B) NaBr, ΔrH = -0.60 kJ mol-1 
C) NaNO3, ΔrH = 20.50 kJ mol-1 
D) LiNO3, ΔrH = -2.51 kJ mol-1 
E) LiBr∙2H2O, ΔrH = -23.26 kJ mol-1

Question 20

Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter. The reaction causes the temperature of the resulting solution to fall below room temperature. Which of the following statements is TRUE?

Accepted Answer

A) The products have a lower potential energy than the reactants. 
B) This type of experiment will provide data to calculate ΔrU. 
C) The reaction is exothermic. 
D) Energy is leaving the system during the reaction. 
E) None of the above statements is true. 
A) The products have a lower potential energy than the reactants. 
B) This type of experiment will provide data to calculate ΔrU. 
C) The reaction is exothermic. 
D) Energy is leaving the system during the reaction. 
E) None of the above statements is true.

Exam 6: Thermochemistry

Match the following. -energy associated with the position of an object

Define heat capacity.

A 5.00 g sample of copper metal at 25.0 °C is heated by the addition of 96.0 J of energy. The final temperature of the copper is ________°C. The specific heat capacity of copper is 0.38 J g-1 K-1.

Use the ΔfH° and ΔrH° information provided to calculate ΔfH° for IF: ΔfH° (kJ mol-1) IF7(g)+ I2(g)→ IF5(g)+ 2IF(g)ΔrH° = -89 kJ IF7(g) -941 IF5(g) -840

Identify the units of specific heat capacity.

Calculate the change in internal energy (ΔU)for a system that is giving off 25.0 kJ of heat and is changing from 12.00 L to 6.00 L in volume at 1.50 bar. (Remember that 100 J = 1 L bar)

Calculate the final temperature of 82.1 g of molecular hydrogen (specific heat capacity = 14.304 J g-1 °C-1)initially at 5.48 °C that absorbs 57 kJ of energy from the surroundings.

Which of the following is NOT a standard state?

A bomb calorimeter with a heat capacity of 13.9 kJ °C-1 has an initial temperature of 21.9 °C. If 5.00 g of propanal (C3H6O, molar mass = 58.0791 g mol-1, Δ\DeltaΔ rU = -1822.7 kJ mol-1 for combustion)is combusted, calculate the final temperature of the calorimeter.

Identify the greatest source of energy worldwide.

Use the ΔfH° information provided to calculate ΔrH° for the following: ΔfH° (kJ mol-1) SO2Cl2 (g)+ 2H2O(l)→ 2HCl(g)+ H2SO4(l)ΔrH° = ? SO2Cl2(g)-364 H2O(l) -286 HCl(g) 92 H2SO4(l)-814

Identify a substance that is NOT in its standard state.

Identify the units of heat capacity.

At constant pressure, the combustion of 20.0 g of C2H6(g)releases 1036 kJ of heat. What is ΔH for the reaction given below? 2C2H6(g)+ 7O2(g)→ 4CO2(g)+ 6H2O(l)

At 1.0133 bar, the heat of sublimation of gallium is 277 kJ mol-1 and the heat of vaporization is 271 kJ mol-1. To the correct number of significant figures, how much heat is required to melt 5.50 mol of gallium at 1.0133 bar?

According to the following thermochemical equation, what mass of H2O (in g)must form to produce 975 kJ of energy? SiO2(s)+ 4HF(g)→ SiF4(g)+ 2H2O(l)ΔrH° = -184 kJ

Write the reaction illustrating ΔfH° of CaCO3 and draw the enthalpy diagram showing the relative positions of the reactants and products if it is an exothermic reaction.

10.618 g of an unknown salt is dissolved in a coffee cup calorimeter that contains 50.0 mL of water. The measured temperature decreased from 23.8 °C to 22.7 °C. Identify the unknown salt. The specific heat of water is 4.184 J g-1 °C-1, and assume the density of the solution is 1.00 g mL-1.

Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter. The reaction causes the temperature of the resulting solution to fall below room temperature. Which of the following statements is TRUE?

Units of Measurement for Physical and Chemical Change

Atoms and Elements

Molecules, Compounds, and Nomenclature

Chemical Reactions and Stoichiometry

Gases

The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding Ii: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory

Liquids, Solids, and Intermolecular Forces

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Gibbs Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry I: Structures

Organic Chemistry II: Reactions

Biochemistry

Chemistry of the Nonmetals

Metals and Metallury

Transition Metals and Coordination Compounds

Filters

A 5.00 g sample of copper metal at 25.0 °C is heated by the addition of 96.0 J of energy. The final temperature of the copper is ________°C. The specific heat capacity of copper is 0.38 J g^-1 K^-1.

Use the Δ_fH° and Δ_rH° information provided to calculate Δ_fH° for IF: Δ_fH°(kJ mol^-1₎ IF₇(g)+ I₂(g)→ IF₅(g)+ 2IF(g)Δ_rH°= -89 kJ IF₇(g) -941 IF₅(g) -840

Calculate the final temperature of 82.1 g of molecular hydrogen (specific heat capacity = 14.304 J g^-1 °C^-1)initially at 5.48 °C that absorbs 57 kJ of energy from the surroundings.

A bomb calorimeter with a heat capacity of 13.9 kJ °C^-1 has an initial temperature of 21.9 °C. If 5.00 g of propanal (C₃H₆O, molar mass = 58.0791 g mol^-1, $\Delta$ _rU = -1822.7 kJ mol^-1 for combustion)is combusted, calculate the final temperature of the calorimeter.

Use the Δ_fH° information provided to calculate Δ_rH° for the following: Δ_fH°(kJ mol^-1) SO₂Cl₂ (g)+ 2H₂O(l)→ 2HCl(g)+ H₂SO4(l)Δ_rH°= ? SO₂Cl₂(g)-364 H₂O(l) -286 HCl(g) 92 H₂SO₄(l)-814

At constant pressure, the combustion of 20.0 g of C₂H₆(g)releases 1036 kJ of heat. What is ΔH for the reaction given below? 2C₂H₆(g)+ 7O₂(g)→ 4CO₂(g)+ 6H₂O(l)

At 1.0133 bar, the heat of sublimation of gallium is 277 kJ mol^-1 and the heat of vaporization is 271 kJ mol^-1. To the correct number of significant figures, how much heat is required to melt 5.50 mol of gallium at 1.0133 bar?

According to the following thermochemical equation, what mass of H₂O (in g)must form to produce 975 kJ of energy? SiO₂(s)+ 4HF(g)→ SiF₄(g)+ 2H₂O(l)Δ_rH°= -184 kJ

Write the reaction illustrating Δ_fH° of CaCO₃ and draw the enthalpy diagram showing the relative positions of the reactants and products if it is an exothermic reaction.

10.618 g of an unknown salt is dissolved in a coffee cup calorimeter that contains 50.0 mL of water. The measured temperature decreased from 23.8 °C to 22.7 °C. Identify the unknown salt. The specific heat of water is 4.184 J g^-1 °C^-1, and assume the density of the solution is 1.00 g mL^-1.