Question 1

A chemical reaction took place in a 5 liter cylindrical enclosure fitted with a piston (like the cylinder in an internal combustion engine) . Over the time required for the reaction to be completed, the volume of the system changed from 1.40 liters to 3.70 liters. Which of the following statements below is true?

Accepted Answer

A)  The enthalpy of the system remained unchanged.
B)  The enthalpy of the system decreased.
C)  The enthalpy of the system increased.
D)  Work was performed by the system.
E)  Work was performed on the system.F) A) and B)
G) A) and C)

Question 2

A constant pressure calorimeter has metal parts (heat capacity of 925.0 J °C-1) and 1.100 × 103 grams of oil (specific heat = 2.824 J g-1 °C-1) , both at 25.40°C. Adding a 5.50 × 102 g slug at 220.0°C, caused the temperature to rise to 35.2 °C. Find the specific heat of the metal.Hint: Consider the amount of energy that was required to raise the temperature of the entire system.

Accepted Answer

A)  0.365 J g-1 °C-1
B)  0.389 J g-1 °C-1
C)  0.395 J g-1 °C-1
D)  0.551 J g-1 °C-1
E)  1.20 J g-1 °C-1F) A) and B)
G) C) and D)

Question 3

Which is a unit of energy, but is not the SI unit of energy?

Accepted Answer

A)  joule
B)  newton
C)  pascal
D)  watt
E)  calorieF) A) and B)
G) B) and C)

Question 4

A 55.00 gram pellet of lead at 25 °C is added to 58.5 g of boiling water (specific heat of 4.18 J g-1 °C-1) at 100 °C in an insulated cup. If the final temperature of the water in the cup is97.9 °C, what is the specific heat of lead?

Accepted Answer

A)  17.8 J g-1 °C-1
B)  0.128 J g-1 °C-1
C)  4.17 J g-1 °C-1
D)  22.2 J g-1 °C-1
E)  0.372 J g-1 °C-1F) A) and B)
G) A) and C)

Question 5

The thermochemical equation that is associated with  Δ\DeltaΔ H°f, the standard enthalpy of formation for glucose, C6H12O6(s) , is

Accepted Answer

A)  6 C(s) + 6 H2O(l)  →\rarr→  C6H12O6(s) .
B)  6 C(s) + 12 H(g) + 6 O(g)  →\rarr→ C6H12O6(s) .
C)  6 C(s) + 6 H2(g) + 3 O2(g)  →\rarr→  C6H12O6(s) .
D)  2 C2H5OH(l) + 2 CO2(g)  →\rarr→  C6H12O6(s) .
E)  6 C(g) + 6 H2(g) + 3 O2(g)  →\rarr→  C6H12O6(s) . F) A) and C)
G) C) and D)

Question 6

Determine the enthalpy change, ?H, for the reaction, N2(g) + 2H2(g)  →\rarr→ N2H4(l) , given the following thermochemical equations: 2(g) + 2H2(g)  \rarr N2H4(l) , given the following thermochemical equations:   A) -151.7 kJ B) -236.2 kJ C) +106.1 kJ D) +50.2 kJ E) +567.4 kJ " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  -151.7 kJ
B)  -236.2 kJ
C)  +106.1 kJ
D)  +50.2 kJ
E)  +567.4 kJ F) A) and B)
G) B) and D)

Question 7

Which is a unit of energy?

Accepted Answer

A)  pascal
B)  newton
C)  joule
D)  watt
E)  ampereF) A) and B)
G) D) and E)

Question 8

A 500.0 gram sample of aluminum is initially at 25.0 °C. It absorbs 32.60 kJ of heat from its surroundings. What is its final temperature, in °C? (specific heat = 0.9930 J g-1 °C-1 for aluminum)

Accepted Answer

A)  40.4 °C
B)  64.7 °C
C)  65.7 °C
D)  89.7 °C
E)  90.7 °CF) B) and D)
G) None of the above

Question 9

The temperature change, measured in Kelvins, experienced by an object, is directly proportional to the heat it absorbs.

Accepted Answer

A) True 
 B)False

Question 10

When 0.250 moles of LiCl are added to 200.0 g of water in a constant pressure calorimeter a temperature change of +11.08 °C is observed. Given that the specific heat of the resulting solution is 4.184 J g-1 °C and we can ignore the small amount of energy absorbed by the calorimeter, what is the molar enthalpy of solution ( Δ\DeltaΔ Hsol) for LiCl?Hint: Do not ignore the specific heat of water in this problem.

Accepted Answer

A)  37.1 kJ/mol
B)  -185.4 kJ/mol
C)  -37.1 kJ/mol
D)  18.5 kJ/mol
E)  -18.5 kJ/mol F) A) and B)
G) A) and C)

Question 11

A closed, uninsulated system was fitted with a movable piston. Introduction of 483 J of heat caused the system to expand, doing 320 J of work in the process against a constant pressure of 101 kPa (kilopascals) . What is the value of  Δ\DeltaΔ H for this process?

Accepted Answer

A)  (483 + 320) joules
B)  (483 - 320) joules
C)  (320 - 483) joules
D)  483 joules
E)  (-320 - 483) joules F) B) and C)
G) All of the above

Question 12

A 25.00 gram pellet of lead (specific heat = 0.128 J g-1 °C-1) at 25 °C is added to 95.3 g of boiling water (specific heat of 4.18 J g-1 °C-1) at 100 °C in an insulated cup. What is the expected final temperature of the water?

Accepted Answer

A)  26.6 °C
B)  62.5 °C
C)  84.4 °C
D)  99.4 °C
E)  100.6 °CF) A) and B)
G) A) and C)

Question 13

When the Kelvin temperature of a sample of molecules increases, its average kinetic energy ________.

Accepted Answer

The answer of When the Kelvin temperature of a sample...

Question 14

The standard enthalpy of combustion for oxalic acid, H2C2O4(s), is −251.9 kJ mol−1. Using this data and the standard enthalpies of formation,  calculate the standard enthalpy of formation of H2C2O4(s), in kJ mol−1.Hint: Pay careful attention to your signs when calculating the enthalpy.

Accepted Answer

Question 15

The standard enthalpy of combustion for xylene, C8H10(l) , is -3908 kJ mol-1. Using this information and the standard enthalpies of formation of the following,  Δ\DeltaΔ H°f:H2O(l) = -285.9 kJ mol-1; CO2(g) = -393.5 kJ mol-1, calculate the standard enthalpy of formation of C8H10(l) , in kJ mol-1.Hint: To begin, determine the thermochemical equation associated with the standard enthalpy for the formation of xylene.

Accepted Answer

A)  -669.5 kJ
B)  +3228.6 kJ
C)  -3228.6 kJ
D)  +4587.4 kJ
E)  +8485.5 kJ F) B) and D)
G) B) and C)

Question 16

Determine the standard enthalpy change,  Δ\DeltaΔ H°, for the reaction, CCl4(l) + 4HCl(g)  →\rarr→  CH4(g) + 4Cl2(g) , given the following thermochemical equations: 4(l) + 4HCl(g)  \rarr  CH4(g) + 4Cl2(g) , given the following thermochemical equations:   Hint: Pay careful attention to your signs. If you reverse an equation remember to change the sign appropriately. A) +55.3 kJ B) -187 kJ C) +101 kJ D) -179 kJ E) +433 kJ " class="answers-bank-image d-inline" rel="preload" > Hint: Pay careful attention to your signs. If you reverse an equation remember to change the sign appropriately.

Accepted Answer

A)  +55.3 kJ
B)  -187 kJ
C)  +101 kJ
D)  -179 kJ
E)  +433 kJ F) A) and D)
G) C) and D)

Question 17

For a chemical reaction in which the change is endothermic, the sign of the enthalpy change, H, is ________.

Accepted Answer

The answer of For a chemical reaction in which the...

Question 18

During an endothermic chemical reaction,

Accepted Answer

A)  a system becomes warmer and the chemical substances undergo an increase in potential energy.
B)  a system becomes warmer and the chemical substances undergo a decrease in potential energy.
C)  a system becomes cooler and the chemical substances undergo an increase in potential energy.
D)  a system becomes cooler and the chemical substances undergo a decrease in potential energy.
E)  a system becomes warmer and additional heat is gained from the surroundings.F) None of the above
G) A) and B)

Question 19

Determine the enthalpy change,  Δ\DeltaΔ H, for the reaction, W(s) + C(s) ? WC(s) , given the following thermochemical equations:

Accepted Answer

A)  +33.3 kJ
B)  -38.2 kJ
C)  +106.1 kJ
D)  -52.9 kJ
E)  +177.4 kJ F) A) and C)
G) A) and E)

Question 20

Given the thermochemical equation, 3 M(s)+ 3 O2(g)→ 3 MO2(s)with a standard enthalpy of reaction = −1443 kJ, calculate the value for ΔH°reaction for the reaction:MO2(s)→ M(s)+ O2(g).

Accepted Answer

Exam 7: Energy and Chemical Change

During an endothermic chemical reaction,

Correct Answer
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A 25.00 gram pellet of lead (specific heat = 0.128 J g^-1 °C^-1) at 25 °C is added to 95.3 g of boiling water (specific heat of 4.18 J g^-1 °C^-1) at 100 °C in an insulated cup. What is the expected final temperature of the water?

Correct Answer
verified

A closed, uninsulated system was fitted with a movable piston. Introduction of 483 J of heat caused the system to expand, doing 320 J of work in the process against a constant pressure of 101 kPa (kilopascals) . What is the value of $\Delta$ H for this process?

Correct Answer
verified

Correct Answer
verified

Given the thermochemical equation, 3 M(s)+ 3 O₂(g)→ 3 MO₂(s)with a standard enthalpy of reaction = −1443 kJ, calculate the value for ΔH°_reaction for the reaction:MO₂(s)→ M(s)+ O₂(g).

Correct Answer
verified

For a chemical reaction in which the change is endothermic, the sign of the enthalpy change, H, is ________.

Correct Answer
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Correct Answer
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Which is a unit of energy, but is not the SI unit of energy?

Correct Answer
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Correct Answer
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Correct Answer
verified

When the Kelvin temperature of a sample of molecules increases, its average kinetic energy ________.

Correct Answer
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Correct Answer
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The thermochemical equation that is associated with $\Delta$ H°_f, the standard enthalpy of formation for glucose, C₆H₁₂O₆(s) , is

Correct Answer
verified

Correct Answer
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A 500.0 gram sample of aluminum is initially at 25.0 °C. It absorbs 32.60 kJ of heat from its surroundings. What is its final temperature, in ^°C? (specific heat = 0.9930 J g^-1 °C^-1 for aluminum)

Correct Answer
verified

The temperature change, measured in Kelvins, experienced by an object, is directly proportional to the heat it absorbs.

Correct Answer
verified

Which is a unit of energy?

Correct Answer
verified

Correct Answer
verified

A 55.00 gram pellet of lead at 25 °C is added to 58.5 g of boiling water (specific heat of 4.18 J g^-1 °C^-1) at 100 °C in an insulated cup. If the final temperature of the water in the cup is97.9 °C, what is the specific heat of lead?

Correct Answer
verified

Correct Answer
verified

Exam 7: Energy and Chemical Change

During an endothermic chemical reaction,

Correct AnswerverifiedShow Answer

A 25.00 gram pellet of lead (specific heat = 0.128 J g-1 °C-1) at 25 °C is added to 95.3 g of boiling water (specific heat of 4.18 J g-1 °C-1) at 100 °C in an insulated cup. What is the expected final temperature of the water?

Correct AnswerverifiedShow Answer

A closed, uninsulated system was fitted with a movable piston. Introduction of 483 J of heat caused the system to expand, doing 320 J of work in the process against a constant pressure of 101 kPa (kilopascals) . What is the value of Δ\DeltaΔ H for this process?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Given the thermochemical equation, 3 M(s)+ 3 O2(g)→ 3 MO2(s)with a standard enthalpy of reaction = −1443 kJ, calculate the value for ΔH°reaction for the reaction:MO2(s)→ M(s)+ O2(g).

Correct AnswerverifiedShow Answer

For a chemical reaction in which the change is endothermic, the sign of the enthalpy change, H, is ________.

Correct AnswerverifiedShow Answer

Determine the standard enthalpy change, Δ\DeltaΔ H°, for the reaction, CCl4(l) + 4HCl(g) →\rarr→ CH4(g) + 4Cl2(g) , given the following thermochemical equations: Hint: Pay careful attention to your signs. If you reverse an equation remember to change the sign appropriately.

Correct AnswerverifiedShow Answer

Which is a unit of energy, but is not the SI unit of energy?

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Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

When the Kelvin temperature of a sample of molecules increases, its average kinetic energy ________.

Correct AnswerverifiedShow Answer

Determine the enthalpy change, ?H, for the reaction, N2(g) + 2H2(g) →\rarr→ N2H4(l) , given the following thermochemical equations:

Correct AnswerverifiedShow Answer

The thermochemical equation that is associated with Δ\DeltaΔ H°f, the standard enthalpy of formation for glucose, C6H12O6(s) , is

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A 500.0 gram sample of aluminum is initially at 25.0 °C. It absorbs 32.60 kJ of heat from its surroundings. What is its final temperature, in °C? (specific heat = 0.9930 J g-1 °C-1 for aluminum)

Correct AnswerverifiedShow Answer

The temperature change, measured in Kelvins, experienced by an object, is directly proportional to the heat it absorbs.

Correct AnswerverifiedShow Answer

Which is a unit of energy?

Correct AnswerverifiedShow Answer

Determine the enthalpy change, Δ\DeltaΔ H, for the reaction, W(s) + C(s) ? WC(s) , given the following thermochemical equations:

Correct AnswerverifiedShow Answer

A 55.00 gram pellet of lead at 25 °C is added to 58.5 g of boiling water (specific heat of 4.18 J g-1 °C-1) at 100 °C in an insulated cup. If the final temperature of the water in the cup is97.9 °C, what is the specific heat of lead?

Correct AnswerverifiedShow Answer

The standard enthalpy of combustion for oxalic acid, H2C2O4(s), is −251.9 kJ mol−1. Using this data and the standard enthalpies of formation, calculate the standard enthalpy of formation of H2C2O4(s), in kJ mol−1.Hint: Pay careful attention to your signs when calculating the enthalpy.

Correct AnswerverifiedShow Answer

Correct Answer
verified

A 25.00 gram pellet of lead (specific heat = 0.128 J g^-1 °C^-1) at 25 °C is added to 95.3 g of boiling water (specific heat of 4.18 J g^-1 °C^-1) at 100 °C in an insulated cup. What is the expected final temperature of the water?

Correct Answer
verified

A closed, uninsulated system was fitted with a movable piston. Introduction of 483 J of heat caused the system to expand, doing 320 J of work in the process against a constant pressure of 101 kPa (kilopascals) . What is the value of $\Delta$ H for this process?

Correct Answer
verified

Correct Answer
verified

Given the thermochemical equation, 3 M(s)+ 3 O₂(g)→ 3 MO₂(s)with a standard enthalpy of reaction = −1443 kJ, calculate the value for ΔH°_reaction for the reaction:MO₂(s)→ M(s)+ O₂(g).

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
verified

Correct Answer
verified

The thermochemical equation that is associated with $\Delta$ H°_f, the standard enthalpy of formation for glucose, C₆H₁₂O₆(s) , is

Correct Answer
verified

Correct Answer
verified

A 500.0 gram sample of aluminum is initially at 25.0 °C. It absorbs 32.60 kJ of heat from its surroundings. What is its final temperature, in ^°C? (specific heat = 0.9930 J g^-1 °C^-1 for aluminum)

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A 55.00 gram pellet of lead at 25 °C is added to 58.5 g of boiling water (specific heat of 4.18 J g^-1 °C^-1) at 100 °C in an insulated cup. If the final temperature of the water in the cup is97.9 °C, what is the specific heat of lead?

Correct Answer
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Correct Answer
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