Question 1

A home aquarium is an example of an open system.

Accepted Answer

A) True 
 B)False  True

Question 2

Calculate the amount of heat necessary to raise the temperature of 12.0 g of water from 15.4°C to 93.0°C. The specific heat of water = 4.18 J/g·°C.

Accepted Answer

A) 0.027 J 
B) 324 J 
C) 389 J 
D) 931 J 
E) 3,890 J 
A) 0.027 J 
B) 324 J 
C) 389 J 
D) 931 J 
E) 3,890 J E

Question 3

An exothermic reaction causes the surroundings to

Accepted Answer

A) warm up. 
B) become acidic. 
C) expand. 
D) decrease its temperature. 
E) release CO2. 
A) warm up. 
B) become acidic. 
C) expand. 
D) decrease its temperature. 
E) release CO2. A

Question 4

Radiant energy is

Accepted Answer

A) the energy stored within the structural units of chemical substances. 
B) the energy associated with the random motion of atoms and molecules. 
C) solar energy, i.e. energy that comes from the sun. 
D) energy available by virtue of an object's position. 
A) the energy stored within the structural units of chemical substances. 
B) the energy associated with the random motion of atoms and molecules. 
C) solar energy, i.e. energy that comes from the sun. 
D) energy available by virtue of an object's position.

Question 5

Suppose a 50.0 g block of silver (specific heat = 0.2350 J/g·°C)at 100°C is placed in contact with a 50.0 g block of iron (specific heat = 0.4494 J/g·°C)at 0°C, and the two blocks are insulated from the rest of the universe. The final temperature of the two blocks

Accepted Answer

A) will be higher than 50°C. 
B) will be lower than 50°C. 
C) will be exactly 50°C. 
D) is unrelated to the composition of the blocks. 
E) cannot be predicted. 
A) will be higher than 50°C. 
B) will be lower than 50°C. 
C) will be exactly 50°C. 
D) is unrelated to the composition of the blocks. 
E) cannot be predicted.

Question 6

In an endothermic process, heat is absorbed by the system.

Accepted Answer

A) True 
 B)False

Question 7

The heat of solution of ammonium chloride is 15.2 kJ/mol. If a 6.134 g sample of NH4Cl is added to 65.0 mL of water in a calorimeter at 24.5°C, what is the minimum temperature reached by the solution? (The specific heat of water = 4.18 J/g·°C; the heat capacity of the calorimeter = 365. J/°C.)

Accepted Answer

A) 27.1°C 
B) 18.6°C 
C) 19.7°C 
D) 21.9°C 
E) 30.4°C 
A) 27.1°C 
B) 18.6°C 
C) 19.7°C 
D) 21.9°C 
E) 30.4°C

Question 8

An average home in Colorado requires 20. GJ of heat per month. How many grams of natural gas (methane)must be burned to supply this energy? CH4(g)+ 2O2(g) $\rarr$CO2(g)+ 2H2O(l)$\Delta$H°rxn= -890.4 kJ/mol

Accepted Answer

A) 1.4 * 103 g 
B) 3.6 * 105 g 
C) 7.1 * 10-4 g 
D) 2.2 * 104 g 
E) 1.4 * 104 g 
A) 1.4 * 103 g 
B) 3.6 * 105 g 
C) 7.1 * 10-4 g 
D) 2.2 * 104 g 
E) 1.4 * 104 g

Question 9

Determine the heat given off to the surroundings when 9.0 g of aluminum reacts according to the equation 2Al + Fe2O3 $\rarr$ Al2O3 + 2Fe, $\Delta$H°rxn= -849 kJ/mol.

Accepted Answer

A) 7.6 * 103 kJ 
B) 2.8 * 102 kJ 
C) 1.4 * 102 kJ 
D) 5.6 * 102 kJ 
E) 2.5 * 103 kJ 
A) 7.6 * 103 kJ 
B) 2.8 * 102 kJ 
C) 1.4 * 102 kJ 
D) 5.6 * 102 kJ 
E) 2.5 * 103 kJ

Question 10

Calculate the standard enthalpy of formation of liquid methanol, CH3OH(l), using the following information: C(graph)+ O2 $\rarr$CO2(g)$\Delta$H° = -393.5 kJ/mol
H2(g)+ (1/2)O2 $\rarr$ H2O(l)$\Delta$H° = -285.8 kJ/mol
CH3OH(l)+ (3/2)O2(g)$\rarr$CO2(g)+ 2H2O(l)$\Delta$H° = -726.4 kJ/mol

Accepted Answer

A) -1,691.5 kJ/mol 
B) -238.7 kJ/mol 
C) 1691.5 kJ/mol 
D) 47.1 kJ/mol 
E) -47.1 kJ/mol 
A) -1,691.5 kJ/mol 
B) -238.7 kJ/mol 
C) 1691.5 kJ/mol 
D) 47.1 kJ/mol 
E) -47.1 kJ/mol

Question 11

For which of these reactions will the difference between $\Delta$H° and $\Delta$E° be the smallest?

Accepted Answer

A) N2(g)+ 3H2(g)$\rarr$2NH3(g) 
B) 4PH3(g)$\rarr$P4(g)+ 6H2(g) 
C) H2(g)+ Cl2(g)$\rarr$2HCl(g) 
D) CO2(g)+ 2H2O(l)$\rarr$CH4(g)+ 2O2(g) 
E) P4(s)+ 10Cl2(g)$\rarr$4PCl5(s) 
A) N2(g)+ 3H2(g)$\rarr$2NH3(g) 
B) 4PH3(g)$\rarr$P4(g)+ 6H2(g) 
C) H2(g)+ Cl2(g)$\rarr$2HCl(g) 
D) CO2(g)+ 2H2O(l)$\rarr$CH4(g)+ 2O2(g) 
E) P4(s)+ 10Cl2(g)$\rarr$4PCl5(s)

Question 12

Calculate the standard enthalpy change for the reaction 2C8H18(l)+ 17O2(g)$\rarr$16CO(g)+ 18H2O(l).
Given:
2C8H18(l)+ 25O2(g)$\rarr$ 16CO2(g)+ 18H2O(l)$\Delta$H° = -11,020 kJ/mol
2CO(g)+ O2(g)$\rarr$2CO2(g)$\Delta$H° = -566.0 kJ/mol

Accepted Answer

A) 10,450 kJ/mol 
B) 6,492 kJ/mol 
C) 15,550 kJ/mol 
D) -6,492 kJ/mol 
E) -10.450 kJ/mol 
A) 10,450 kJ/mol 
B) 6,492 kJ/mol 
C) 15,550 kJ/mol 
D) -6,492 kJ/mol 
E) -10.450 kJ/mol

Question 13

Calculate the enthalpy of reaction for H2(g)+ C2H4(g)$\rarr$ C2H6(g).
[$\Delta$H°f(C2H4(g))= 52.3 kJ/mol; $\Delta$H°f(C2H6(g))= -84.7 kJ/mol]

Accepted Answer

The answer of Calculate the enthalpy of reaction for H2(g)+...

Question 14

Octane (C8H18)undergoes combustion according to the following thermochemical equation: 2C8H18(l)+ 25O2(g)$\rarr$ 16CO2(g)+ 18H2O(l)$\Delta$H°rxn = -11,020 kJ/mol.
Given that $\Delta$H°f[CO2(g)] = -393.5 kJ/mol and $\Delta$H°f[H2O(l)] = -285.8 kJ/mol, calculate the standard enthalpy of formation of octane.

Accepted Answer

A) -210 kJ/mol 
B) -11,230 kJ/mol 
C) 22,040 kJ/mol 
D) -420 kJ/mol 
E) 420 kJ/mol 
A) -210 kJ/mol 
B) -11,230 kJ/mol 
C) 22,040 kJ/mol 
D) -420 kJ/mol 
E) 420 kJ/mol

Question 15

What is the standard enthalpy of formation of H2(g)at 25°C?

Accepted Answer

Question 16

The enthalpy change when a strong acid is neutralized by strong base is -56.1 kJ/mol. If 135 mL of 0.450 M HI at 23.15°C is mixed with 145 mL of 0.500 M NaOH, also at 23.15°C, what will be the maximum temperature reached by the resulting solution? (Assume that there is no heat loss to the container, that the specific heat of the final solution is 4.18 J/g·°C, and that the density of the final solution is that of water.)

Accepted Answer

A) 26.06°C 
B) 29.19°C 
C) 32.35°C 
D) 20.24°C 
E) 36.57°C 
A) 26.06°C 
B) 29.19°C 
C) 32.35°C 
D) 20.24°C 
E) 36.57°C

Question 17

To which one of the following reactions occurring at 25°C does the symbol $\Delta$H°f[HNO3(l)] refer?

Accepted Answer

A) H(g)+ N(g)+ O3(g)$\rarr$HNO3(l) 
B) (1/2)H2(g)+ (1/2)N2(g)+ (3/2)O2(g)$\rarr$HNO3(l) 
C) HNO3(l)$\rarr$(1/2)H2(g)+ (1/2)N2(g)+ (3/2)O2(g) 
D) HNO3(l)$\rarr$ H(g)+ N(g)+ 3O(g) 
E) H2(g)+ N2(g)+ O3(g)$\rarr$ HNO3(l) 
A) H(g)+ N(g)+ O3(g)$\rarr$HNO3(l) 
B) (1/2)H2(g)+ (1/2)N2(g)+ (3/2)O2(g)$\rarr$HNO3(l) 
C) HNO3(l)$\rarr$(1/2)H2(g)+ (1/2)N2(g)+ (3/2)O2(g) 
D) HNO3(l)$\rarr$ H(g)+ N(g)+ 3O(g) 
E) H2(g)+ N2(g)+ O3(g)$\rarr$ HNO3(l)

Question 18

An endothermic reaction causes the surroundings to

Accepted Answer

A) warm up. 
B) become acidic. 
C) condense. 
D) decrease in temperature. 
E) release CO2 . 
A) warm up. 
B) become acidic. 
C) condense. 
D) decrease in temperature. 
E) release CO2 .

Question 19

A 0.3423 g sample of pentane, C5H12, was burned in a bomb calorimeter. The temperature of the calorimeter and the 1.000 kg of water contained therein rose from 20.22°C to 22.82°C. The heat capacity of the calorimeter is 2.21 kJ/°C. The heat capacity of water = 4.184 J/g·°C. What is the heat of combustion, in megajoules (MJ), per mole of pentane?

Accepted Answer

Question 20

When 0.7521 g of benzoic acid was burned in a calorimeter containing 1,000. g of water, a temperature rise of 3.60°C was observed. What is the heat capacity of the bomb calorimeter, excluding the water? The heat of combustion of benzoic acid is -26.42 kJ/g.

Accepted Answer

A) 15.87 kJ/°C 
B) 4.18 kJ/°C 
C) 5.52 kJ/°C 
D) 1.34 kJ/°C 
E) 752.1 kJ/°C 
A) 15.87 kJ/°C 
B) 4.18 kJ/°C 
C) 5.52 kJ/°C 
D) 1.34 kJ/°C 
E) 752.1 kJ/°C

A home aquarium is an example of an open system.

Calculate the amount of heat necessary to raise the temperature of 12.0 g of water from 15.4°C to 93.0°C. The specific heat of water = 4.18 J/g·°C.

An exothermic reaction causes the surroundings to

Radiant energy is

Suppose a 50.0 g block of silver (specific heat = 0.2350 J/g·°C)at 100°C is placed in contact with a 50.0 g block of iron (specific heat = 0.4494 J/g·°C)at 0°C, and the two blocks are insulated from the rest of the universe. The final temperature of the two blocks

In an endothermic process, heat is absorbed by the system.

The heat of solution of ammonium chloride is 15.2 kJ/mol. If a 6.134 g sample of NH₄Cl is added to 65.0 mL of water in a calorimeter at 24.5°C, what is the minimum temperature reached by the solution? (The specific heat of water = 4.18 J/g·°C; the heat capacity of the calorimeter = 365. J/°C.)

An average home in Colorado requires 20. GJ of heat per month. How many grams of natural gas (methane)must be burned to supply this energy? CH₄(g)+ 2O₂(g) $\rarr$ CO₂(g)+ 2H₂O(l) $\Delta$ H°_rxn= -890.4 kJ/mol

Determine the heat given off to the surroundings when 9.0 g of aluminum reacts according to the equation 2Al + Fe₂O₃ $\rarr$ Al₂O₃ + 2Fe, $\Delta$ H°_rxn= -849 kJ/mol.

For which of these reactions will the difference between $\Delta$ H° and $\Delta$ E° be the smallest?

Calculate the standard enthalpy change for the reaction 2C₈H₁₈(l)+ 17O₂(g) $\rarr$ 16CO(g)+ 18H₂O(l). Given: 2C₈H₁₈(l)+ 25O₂(g) $\rarr$ 16CO₂(g)+ 18H₂O(l) $\Delta$ H° = -11,020 kJ/mol 2CO(g)+ O₂(g) $\rarr$ 2CO₂(g) $\Delta$ H° = -566.0 kJ/mol

Calculate the enthalpy of reaction for H₂(g)+ C₂H₄(g) $\rarr$ C₂H₆(g). [ $\Delta$ H°_f(C₂H₄(g))= 52.3 kJ/mol; $\Delta$ H°_f(C₂H₆(g))= -84.7 kJ/mol]

What is the standard enthalpy of formation of H₂(g)at 25°C?

To which one of the following reactions occurring at 25°C does the symbol $\Delta$ H°_f[HNO₃(l)] refer?

An endothermic reaction causes the surroundings to

When 0.7521 g of benzoic acid was burned in a calorimeter containing 1,000. g of water, a temperature rise of 3.60°C was observed. What is the heat capacity of the bomb calorimeter, excluding the water? The heat of combustion of benzoic acid is -26.42 kJ/g.

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Thermodynamics

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

Exam 6: Energy Relationships in Chemical Reactions

A home aquarium is an example of an open system.

Calculate the amount of heat necessary to raise the temperature of 12.0 g of water from 15.4°C to 93.0°C. The specific heat of water = 4.18 J/g·°C.

An exothermic reaction causes the surroundings to

Radiant energy is

Suppose a 50.0 g block of silver (specific heat = 0.2350 J/g·°C)at 100°C is placed in contact with a 50.0 g block of iron (specific heat = 0.4494 J/g·°C)at 0°C, and the two blocks are insulated from the rest of the universe. The final temperature of the two blocks

In an endothermic process, heat is absorbed by the system.

The heat of solution of ammonium chloride is 15.2 kJ/mol. If a 6.134 g sample of NH4Cl is added to 65.0 mL of water in a calorimeter at 24.5°C, what is the minimum temperature reached by the solution? (The specific heat of water = 4.18 J/g·°C; the heat capacity of the calorimeter = 365. J/°C.)

An average home in Colorado requires 20. GJ of heat per month. How many grams of natural gas (methane)must be burned to supply this energy? CH4(g)+ 2O2(g) →\rarr→ CO2(g)+ 2H2O(l) Δ\DeltaΔ H°rxn= -890.4 kJ/mol

Determine the heat given off to the surroundings when 9.0 g of aluminum reacts according to the equation 2Al + Fe2O3 →\rarr→ Al2O3 + 2Fe, Δ\DeltaΔ H°rxn= -849 kJ/mol.

For which of these reactions will the difference between Δ\DeltaΔ H° and Δ\DeltaΔ E° be the smallest?

Calculate the standard enthalpy change for the reaction 2C8H18(l)+ 17O2(g) →\rarr→ 16CO(g)+ 18H2O(l). Given: 2C8H18(l)+ 25O2(g) →\rarr→ 16CO2(g)+ 18H2O(l) Δ\DeltaΔ H° = -11,020 kJ/mol 2CO(g)+ O2(g) →\rarr→ 2CO2(g) Δ\DeltaΔ H° = -566.0 kJ/mol

Calculate the enthalpy of reaction for H2(g)+ C2H4(g) →\rarr→ C2H6(g). [ Δ\DeltaΔ H°f(C2H4(g))= 52.3 kJ/mol; Δ\DeltaΔ H°f(C2H6(g))= -84.7 kJ/mol]

What is the standard enthalpy of formation of H2(g)at 25°C?

To which one of the following reactions occurring at 25°C does the symbol Δ\DeltaΔ H°f[HNO3(l)] refer?

An endothermic reaction causes the surroundings to

When 0.7521 g of benzoic acid was burned in a calorimeter containing 1,000. g of water, a temperature rise of 3.60°C was observed. What is the heat capacity of the bomb calorimeter, excluding the water? The heat of combustion of benzoic acid is -26.42 kJ/g.

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Thermodynamics

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

An average home in Colorado requires 20. GJ of heat per month. How many grams of natural gas (methane)must be burned to supply this energy? CH₄(g)+ 2O₂(g) $\rarr$ CO₂(g)+ 2H₂O(l) $\Delta$ H°_rxn= -890.4 kJ/mol

Determine the heat given off to the surroundings when 9.0 g of aluminum reacts according to the equation 2Al + Fe₂O₃ $\rarr$ Al₂O₃ + 2Fe, $\Delta$ H°_rxn= -849 kJ/mol.

For which of these reactions will the difference between $\Delta$ H° and $\Delta$ E° be the smallest?

Calculate the standard enthalpy change for the reaction 2C₈H₁₈(l)+ 17O₂(g) $\rarr$ 16CO(g)+ 18H₂O(l). Given: 2C₈H₁₈(l)+ 25O₂(g) $\rarr$ 16CO₂(g)+ 18H₂O(l) $\Delta$ H° = -11,020 kJ/mol 2CO(g)+ O₂(g) $\rarr$ 2CO₂(g) $\Delta$ H° = -566.0 kJ/mol

Calculate the enthalpy of reaction for H₂(g)+ C₂H₄(g) $\rarr$ C₂H₆(g). [ $\Delta$ H°_f(C₂H₄(g))= 52.3 kJ/mol; $\Delta$ H°_f(C₂H₆(g))= -84.7 kJ/mol]

What is the standard enthalpy of formation of H₂(g)at 25°C?

To which one of the following reactions occurring at 25°C does the symbol $\Delta$ H°_f[HNO₃(l)] refer?