Question 1

Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction: 
4 kJ" class="answers-bank-image d-inline" rel="preload" > 4 kJ" class="answers-bank-image d-inline" rel="preload" > (l) → 4 kJ" class="answers-bank-image d-inline" rel="preload" > O(l) + 4 kJ" class="answers-bank-image d-inline" rel="preload" > (g)  
4 kJ" class="answers-bank-image d-inline" rel="preload" > H = -196 kJ
Calculate the value of q (kJ) in this exothermic reaction when 4.00 g of hydrogen peroxide decomposes at constant pressure?

Accepted Answer

A)  -23.1 kJ
B)  -11.5 kJ
C)  -0.0217 kJ
D)  1.44 kJ
E)  -2.31 × 104 kJF) C) and E)
G) A) and D)

Question 2

The heat of combustion,ΔrHcomb,of 1-butene(l) ,C4H8(l) ,is -2696.9 kJ/mol.From the following values of ΔfH° CO2(g) = -393.5 kJ/mol and ΔfH° H2O(l) = -285.8 kJ/mol,calculate the standard enthalpy of formation of butene(l) .

Accepted Answer

A)  +2017 kJ/mol
B)  -2017 kJ/mol
C)  -3376 kJ/mol
D)  -107.7 kJ/mol
E)  -20.30 kJ/molF) None of the above
G) B) and C)

Question 3

Consider the reaction: 
rH° for this reaction. A) -622.62 kJ/mol B) 984.10 kJ/mol C) -1168.9 kJ/mol D) -241.67 kJ/mol E) -149.29 kJ/mol" class="answers-bank-image d-inline" rel="preload" >
Compute ΔrH° for this reaction.

Accepted Answer

A)  -622.62 kJ/mol
B)  984.10 kJ/mol
C)  -1168.9 kJ/mol
D)  -241.67 kJ/mol
E)  -149.29 kJ/molF) A) and B)
G) D) and E)

Question 4

How much heat is required to raise the temperature of 175 g of aluminum from 21.0 °C to 145 °C? The specific heat of aluminum is 0.903 J g-1 °C-1.

Accepted Answer

A)  19.6 kJ
B)  24.0 kJ
C)  1.27 J
D)  22.9 kJE) A) and D)
F) A) and C)

Question 5

A mixture of 125 g of iron and 250 g of water is heated from 25.0 °C to 70.0 °C.How much heat is absorbed by the mixture? (Specific heat of water = 4.18 J/g °C;iron = 0.473 J/g °C)

Accepted Answer

A)  49.7 kJ
B)  59.6 kJ
C)  47.0 kJ
D)  2.66 kJ
E)  27.6 kJF) A) and B)
G) A) and C)

Question 6

14.0 g of metal at 24.0 °C has 250 joules of heat added to it.The metal's specific heat is 0.105 J/g °C.What is its final temperature?

Accepted Answer

A)  (250) (14.0) /0.105 °C
B)  [250/(14.0) (0.105) ] °C
C)  [250 /(14.0) (0.105) ] + 24.0 °C
D)  (14.0) (0.105) /250 °C
E)  (14.0) (0.105) (250) °CF) A) and B)
G) None of the above

Question 7

Choose the INCORRECT statement.

Accepted Answer

A)  Temperatures of two bodies are equal when the average kinetic energies of the two bodies become the same.
B)  The heat capacity is the quantity of heat required to change the temperature of the system by one degree.
C)  The specific heat is the heat capacity for one mole of substance.
D)  The law of conservation of energy can be written: qsystem + qsurroundings = 0.
E)  Most metals have low specific heats,as metals can be heated quickly.F) A) and E)
G) A) and B)

Question 8

What is the enthalpy of reaction for the neutralization reaction occurring between dilute Ba(OH) 2(aq) and dilute HNO3(aq) ? Values of ΔfH° from data tables are given below.
Hint: Balance the equation so the coefficients are the lowest possible set of whole numbers.
2(aq) and dilute HNO3(aq) ? Values of ΔfH° from data tables are given below. Hint: Balance the equation so the coefficients are the lowest possible set of whole numbers.   A) +426.0 kJ/mol B) -111.6 kJ/mol C) -426.0 kJ/mol D) -571.6 kJ/mol E) -460.0 kJ/mol" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  +426.0 kJ/mol
B)  -111.6 kJ/mol
C)  -426.0 kJ/mol
D)  -571.6 kJ/mol
E)  -460.0 kJ/molF) All of the above
G) D) and E)

Question 9

250.0 g of hot coffee at 95.0 °C are placed in a 0.2000 kg mug at 20.0 °C.The specific heat of the coffee is 4.00 J/g °C,while that of the mug is 0.80 J/g °C.Assuming no heat is lost to the surroundings,what is the final temperature of the system: mug + coffee?

Accepted Answer

A)  61.7 °C
B)  117 °C
C)  76.0 °C
D)  57.5 °C
E)  84.7 °CF) B) and E)
G) B) and D)

Question 10

Enthalpy is an extensive property.

Accepted Answer

A) True 
 B)False

Question 11

Calculate the work needed to make room for products in the combustion of sulfur,S8(s) ,to SO2(g) at STP.

Accepted Answer

A)  0 kJ
B)  -2.27 kJ
C)  -4.54 kJ
D)  -18.2 kJ
E)  +182 kJF) C) and D)
G) A) and B)

Question 12

A sample gives off 2505 cal when burned in a bomb calorimeter.The temperature of the calorimeter assembly increases by 2.24 °C.What is the heat capacity of the calorimeter?

Accepted Answer

A)  8.92 kcal/ °C
B)  1.12 kcal/ °C
C)  2.51 kcal/ °C
D)  5.61 kcal/ °C
E)  2.65 kcal/ °CF) A) and D)
G) D) and E)

Question 13

The enthalpy of a system is the internal energy minus the pressure-volume product.

Accepted Answer

A) True 
 B)False

Question 14

The heat of combustion of several fuels are listed in the table below.On a per gram basis,which fuel releases the most energy?
4(g)  C) CH3OH(l)  D) C3H8(g)  E) H2(g) " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  C(s) 
B)  CH4(g) 
C)  CH3OH(l) 
D)  C3H8(g) 
E)  H2(g) F) None of the above
G) A) and C)

Question 15

Calculate the kinetic energy of a 150 g baseball moving at a speed of 39.m 2 J C) 5.8 × 103 J D) 1.1 × 105 J" class="answers-bank-image d-inline" rel="preload" >
(87 mph) .

Accepted Answer

A)  5.8 J
B)  1.1 × 102 J
C)  5.8 × 103 J
D)  1.1 × 105 JE) B) and C)
F) A) and C)

Question 16

Using the heat of combustion of methanol as -726.6 kJ/mol and the following data:
rH° for the following reaction: CO(g) + 2 H2(g) → CH3OH(l)  A) -349 kJ/mol B) 157.8 kJ/mol C) -157.8 kJ/mol D) 128 kJ/mol E) -128 kJ/mol" class="answers-bank-image d-inline" rel="preload" >
Determine ΔrH° for the following reaction:
CO(g) + 2 H2(g) → CH3OH(l)

Accepted Answer

A)  -349 kJ/mol
B)  157.8 kJ/mol
C)  -157.8 kJ/mol
D)  128 kJ/mol
E)  -128 kJ/molF) B) and D)
G) B) and E)

Question 17

The standard enthalpy of formation for CuSO4 ∙ 5 H2O(s) is -2278.0 kJ/mol at 25 °C.The chemical equation to which this value applies is:

Accepted Answer

A)  Cu(s) + S(s) + 5 H2O(g) + 2 O2(g) → CuSO4 ∙ 5 H2O(s) 
B)  Cu(s) + S(s) + 9/2 O2(g) + 5 H2(g) → CuSO4 ∙ 5 H2O(s) 
C)  Cu(s) + SO4(g) + 5 H2O(g) → CuSO4 ∙ 5 H2O(s) 
D)  Cu(s) + S(s) + 5/9 O2(g) + 5 H2(g) → CuSO4 ∙ 5 H2O(s) 
E)  2 Cu(s) + 2 SO2(g) + 5 H2O(g) → 2 CuSO4 ∙ 5 H2O(s) F) C) and E)
G) A) and B)

Question 18

The specific heat of copper is 0.385 J g-1k-1.If 34.2 g of copper,initially at 21.0 °C,absorbs 4.689 kJ,what will be the final temperature of the copper?

Accepted Answer

A)  21.4 °C
B)  23.8 °C
C)  356 °C
D)  377 °CE) A) and D)
F) None of the above

Question 19

H2S(g) + 3/2 O2(g) → H2O (l) + SO2(g) ΔrH° = -562.3 kJ/mol
1/8 S8(s) + O2(g) → SO2(g) ΔrH° = -297.0 kJ/mol
H2(g) + 1/2O2 → H2O (l) ΔrH° = -266.9 kJ/mol
Compute ΔrH° for H2(g) + 1/8 S8 (s) → H2S(g) in kJ/mol.

Accepted Answer

A)  562.3 kJ/mol
B)  276.6 kJ/mol
C)  265.3 kJ/mol
D)  20.5 kJ/mol
E)  -1.6 kJ/molF) A) and D)
G) C) and D)

Question 20

When 50.0 mL of 0.400 mol L-1 Ca(NO3) 2 is added to 50.0 mL of 0.800 mol L-1 NaF,CaF2 precipitates,as shown in the net ionic equation below.The initial temperature of both solutions is 23.0 °C.Assuming that the reaction goes to completion,and that the resulting solution has a mass of 100.00 g and a specific heat of 4.18 J g-1°C-1 ,calculate the final temperature of the solution.
Ca2+(aq) + 2 F-(aq) → CaF2(s)  
-1 Ca(NO3) 2 is added to 50.0 mL of 0.800 mol L-1 NaF,CaF2 precipitates,as shown in the net ionic equation below.The initial temperature of both solutions is 23.0 °C.Assuming that the reaction goes to completion,and that the resulting solution has a mass of 100.00 g and a specific heat of 4.18 J g-1°C-1 ,calculate the final temperature of the solution. Ca2+(aq) + 2 F-(aq) → CaF2(s)     H = -11.5 kJ A) 22.45 °C B) 23.55 °C C) 24.10 °C D) 24.65 °C" class="answers-bank-image d-inline" rel="preload" > H = -11.5 kJ

Accepted Answer

A)  22.45 °C
B)  23.55 °C
C)  24.10 °C
D)  24.65 °CE) All of the above
F) None of the above

Exam 7: Thermochemistry

Using the heat of combustion of methanol as -726.6 kJ/mol and the following data: Determine Δ_rH° for the following reaction: CO(g) + 2 H₂(g) → CH₃OH(l)

Correct Answer
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Consider the reaction: Compute Δ_rH° for this reaction.

Correct Answer
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Choose the INCORRECT statement.

Correct Answer
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Enthalpy is an extensive property.

Correct Answer
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Calculate the work needed to make room for products in the combustion of sulfur,S₈(s) ,to SO₂(g) at STP.

Correct Answer
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The standard enthalpy of formation for CuSO₄∙ 5 H₂O(s) is -2278.0 kJ/mol at 25 °C.The chemical equation to which this value applies is:

Correct Answer
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How much heat is required to raise the temperature of 175 g of aluminum from 21.0 °C to 145 °C? The specific heat of aluminum is 0.903 J g^-1 °C^-1.

Correct Answer
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The heat of combustion,Δ_rH_comb,of 1-butene(l) ,C₄H₈(l) ,is -2696.9 kJ/mol.From the following values of Δ_fH° CO₂(g) = -393.5 kJ/mol and Δ_fH° H₂O(l) = -285.8 kJ/mol,calculate the standard enthalpy of formation of butene(l) .

Correct Answer
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The heat of combustion of several fuels are listed in the table below.On a per gram basis,which fuel releases the most energy?

Correct Answer
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H₂S(g) + 3/2 O₂(g) → H₂O (l) + SO₂(g) Δ_rH° = -562.3 kJ/mol 1/8 S₈(s) + O₂(g) → SO₂(g) Δ_rH° = -297.0 kJ/mol H₂(g) + 1/2O₂ → H₂O (l) Δ_rH° = -266.9 kJ/mol Compute Δ_rH° for H₂(g) + 1/8 S₈ (s) → H₂S(g) in kJ/mol.

Correct Answer
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A sample gives off 2505 cal when burned in a bomb calorimeter.The temperature of the calorimeter assembly increases by 2.24 °C.What is the heat capacity of the calorimeter?

Correct Answer
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Calculate the kinetic energy of a 150 g baseball moving at a speed of 39.m (87 mph) .

Correct Answer
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What is the enthalpy of reaction for the neutralization reaction occurring between dilute Ba(OH) ₂(aq) and dilute HNO₃(aq) ? Values of Δ_fH° from data tables are given below. Hint: Balance the equation so the coefficients are the lowest possible set of whole numbers.

Correct Answer
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The specific heat of copper is 0.385 J g^-1k^-1.If 34.2 g of copper,initially at 21.0 °C,absorbs 4.689 kJ,what will be the final temperature of the copper?

Correct Answer
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14.0 g of metal at 24.0 °C has 250 joules of heat added to it.The metal's specific heat is 0.105 J/g °C.What is its final temperature?

Correct Answer
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The enthalpy of a system is the internal energy minus the pressure-volume product.

Correct Answer
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250.0 g of hot coffee at 95.0 °C are placed in a 0.2000 kg mug at 20.0 °C.The specific heat of the coffee is 4.00 J/g °C,while that of the mug is 0.80 J/g °C.Assuming no heat is lost to the surroundings,what is the final temperature of the system: mug + coffee?

Correct Answer
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A mixture of 125 g of iron and 250 g of water is heated from 25.0 °C to 70.0 °C.How much heat is absorbed by the mixture? (Specific heat of water = 4.18 J/g °C;iron = 0.473 J/g °C)

Correct Answer
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Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction: (l) → O(l) + (g) H = -196 kJ Calculate the value of q (kJ) in this exothermic reaction when 4.00 g of hydrogen peroxide decomposes at constant pressure?

Correct Answer
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Exam 7: Thermochemistry

Using the heat of combustion of methanol as -726.6 kJ/mol and the following data: Determine ΔrH° for the following reaction: CO(g) + 2 H2(g) → CH3OH(l)

Correct AnswerverifiedShow Answer

Consider the reaction: Compute ΔrH° for this reaction.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Choose the INCORRECT statement.

Correct AnswerverifiedShow Answer

Enthalpy is an extensive property.

Correct AnswerverifiedShow Answer

Calculate the work needed to make room for products in the combustion of sulfur,S8(s) ,to SO2(g) at STP.

Correct AnswerverifiedShow Answer

The standard enthalpy of formation for CuSO4 ∙ 5 H2O(s) is -2278.0 kJ/mol at 25 °C.The chemical equation to which this value applies is:

Correct AnswerverifiedShow Answer

How much heat is required to raise the temperature of 175 g of aluminum from 21.0 °C to 145 °C? The specific heat of aluminum is 0.903 J g-1 °C-1.

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The heat of combustion,ΔrHcomb,of 1-butene(l) ,C4H8(l) ,is -2696.9 kJ/mol.From the following values of ΔfH° CO2(g) = -393.5 kJ/mol and ΔfH° H2O(l) = -285.8 kJ/mol,calculate the standard enthalpy of formation of butene(l) .

Correct AnswerverifiedShow Answer

The heat of combustion of several fuels are listed in the table below.On a per gram basis,which fuel releases the most energy?

Correct AnswerverifiedShow Answer

H2S(g) + 3/2 O2(g) → H2O (l) + SO2(g) ΔrH° = -562.3 kJ/mol 1/8 S8(s) + O2(g) → SO2(g) ΔrH° = -297.0 kJ/mol H2(g) + 1/2O2 → H2O (l) ΔrH° = -266.9 kJ/mol Compute ΔrH° for H2(g) + 1/8 S8 (s) → H2S(g) in kJ/mol.

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A sample gives off 2505 cal when burned in a bomb calorimeter.The temperature of the calorimeter assembly increases by 2.24 °C.What is the heat capacity of the calorimeter?

Correct AnswerverifiedShow Answer

Calculate the kinetic energy of a 150 g baseball moving at a speed of 39.m (87 mph) .

Correct AnswerverifiedShow Answer

What is the enthalpy of reaction for the neutralization reaction occurring between dilute Ba(OH) 2(aq) and dilute HNO3(aq) ? Values of ΔfH° from data tables are given below. Hint: Balance the equation so the coefficients are the lowest possible set of whole numbers.

Correct AnswerverifiedShow Answer

The specific heat of copper is 0.385 J g-1k-1.If 34.2 g of copper,initially at 21.0 °C,absorbs 4.689 kJ,what will be the final temperature of the copper?

Correct AnswerverifiedShow Answer

14.0 g of metal at 24.0 °C has 250 joules of heat added to it.The metal's specific heat is 0.105 J/g °C.What is its final temperature?

Correct AnswerverifiedShow Answer

The enthalpy of a system is the internal energy minus the pressure-volume product.

Correct AnswerverifiedShow Answer

250.0 g of hot coffee at 95.0 °C are placed in a 0.2000 kg mug at 20.0 °C.The specific heat of the coffee is 4.00 J/g °C,while that of the mug is 0.80 J/g °C.Assuming no heat is lost to the surroundings,what is the final temperature of the system: mug + coffee?

Correct AnswerverifiedShow Answer

A mixture of 125 g of iron and 250 g of water is heated from 25.0 °C to 70.0 °C.How much heat is absorbed by the mixture? (Specific heat of water = 4.18 J/g °C;iron = 0.473 J/g °C)

Correct AnswerverifiedShow Answer

Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction: (l) → O(l) + (g) H = -196 kJ Calculate the value of q (kJ) in this exothermic reaction when 4.00 g of hydrogen peroxide decomposes at constant pressure?

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Using the heat of combustion of methanol as -726.6 kJ/mol and the following data: Determine Δ_rH° for the following reaction: CO(g) + 2 H₂(g) → CH₃OH(l)

Correct Answer
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Consider the reaction: Compute Δ_rH° for this reaction.

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Calculate the work needed to make room for products in the combustion of sulfur,S₈(s) ,to SO₂(g) at STP.

Correct Answer
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The standard enthalpy of formation for CuSO₄∙ 5 H₂O(s) is -2278.0 kJ/mol at 25 °C.The chemical equation to which this value applies is:

Correct Answer
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How much heat is required to raise the temperature of 175 g of aluminum from 21.0 °C to 145 °C? The specific heat of aluminum is 0.903 J g^-1 °C^-1.

Correct Answer
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The heat of combustion,Δ_rH_comb,of 1-butene(l) ,C₄H₈(l) ,is -2696.9 kJ/mol.From the following values of Δ_fH° CO₂(g) = -393.5 kJ/mol and Δ_fH° H₂O(l) = -285.8 kJ/mol,calculate the standard enthalpy of formation of butene(l) .

Correct Answer
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Correct Answer
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H₂S(g) + 3/2 O₂(g) → H₂O (l) + SO₂(g) Δ_rH° = -562.3 kJ/mol 1/8 S₈(s) + O₂(g) → SO₂(g) Δ_rH° = -297.0 kJ/mol H₂(g) + 1/2O₂ → H₂O (l) Δ_rH° = -266.9 kJ/mol Compute Δ_rH° for H₂(g) + 1/8 S₈ (s) → H₂S(g) in kJ/mol.

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What is the enthalpy of reaction for the neutralization reaction occurring between dilute Ba(OH) ₂(aq) and dilute HNO₃(aq) ? Values of Δ_fH° from data tables are given below. Hint: Balance the equation so the coefficients are the lowest possible set of whole numbers.

Correct Answer
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The specific heat of copper is 0.385 J g^-1k^-1.If 34.2 g of copper,initially at 21.0 °C,absorbs 4.689 kJ,what will be the final temperature of the copper?

Correct Answer
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