Question 1

The specific heat capacity of liquid mercury is 0.14 J/gK.How many joules of heat are needed to raise the temperature of 7.25 g of mercury from 36.0°C to 75.0°C?

Accepted Answer

A)  2.0 × 103 J 
B)  40 J 
C)  113 J 
D)  5.0 × 10-4 J 
E)  2.1 J 
A)  2.0 × 103 J 
B)  40 J 
C)  113 J 
D)  5.0 × 10-4 J 
E)  2.1 J B

Question 2

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: 4 SO3(g)→ 4 S(s)+ 6 O2(g)ΔH°rxn = ?
Given:
SO2(g)→ S(s)+ O2(g)ΔH°rxn = +296.8 kJ
2 SO2(g)+ O2(g)→ 2 SO3(g)ΔH°rxn = -197.8 kJ

Accepted Answer

A)  -494.6 kJ 
B)  -692.4 kJ 
C)  -791.4 kJ 
D)  1583 kJ 
E)  -293.0 kJ 
A)  -494.6 kJ 
B)  -692.4 kJ 
C)  -791.4 kJ 
D)  1583 kJ 
E)  -293.0 kJ D

Question 3

When 0.500 mol of CH4(g)reacts with excess Cl2(g)at constant pressure according to the chemical equation shown below,354 kJ of heat are released.Calculate the value of ΔH for this reaction,as written. 2 CH4(g)+ 3 Cl2(g)→ 2 CHCl3(l)+ 3 H2(g)ΔH = ?

Accepted Answer

A)  -1420 kJ 
B)  -708 kJ 
C)  +708 kJ 
D)  +1420 kJ 
E)  -710 kJ 
A)  -1420 kJ 
B)  -708 kJ 
C)  +708 kJ 
D)  +1420 kJ 
E)  -710 kJ A

Question 4

At 1 atm pressure,the heat of sublimation of gallium is 277 kJ/mol and the heat of vaporization is 271 kJ/mol.To the correct number of significant figures,how much heat is required to melt 3.50 mol of gallium at 1 atm pressure?

Accepted Answer

A)  6 kJ 
B)  21 kJ 
C)  256 kJ 
D)  274 kJ 
A)  6 kJ 
B)  21 kJ 
C)  256 kJ 
D)  274 kJ

Question 5

Calculate the amount of heat (in kJ)necessary to raise the temperature of 51.8 g benzene by 52.6 K.The specific heat capacity of benzene is 1.05 J/g°C.

Accepted Answer

A)  1.81 kJ 
B)  16.6 kJ 
C)  2.59 kJ 
D)  2.86 kJ 
E)  3.85 kJ 
A)  1.81 kJ 
B)  16.6 kJ 
C)  2.59 kJ 
D)  2.86 kJ 
E)  3.85 kJ

Question 6

Which of the following signs on q and w represent the surroundings that is doing work on the system,as well as gaining heat from the surroundings?

Accepted Answer

A)  q = +, w = - 
B)  q = -, w = + 
C)  q = +, w = + 
D)  q = -, w = - 
E)  None of these represent the system referenced above. 
A)  q = +, w = - 
B)  q = -, w = + 
C)  q = +, w = + 
D)  q = -, w = - 
E)  None of these represent the system referenced above.

Question 7

Identify the compound that is NOT a major air pollutant.

Accepted Answer

A)  water 
B)  sulfur oxides 
C)  nitrogen oxides 
D)  carbon monoxide 
E)  ozone 
A)  water 
B)  sulfur oxides 
C)  nitrogen oxides 
D)  carbon monoxide 
E)  ozone

Question 8

Give the units of heat capacity.

Accepted Answer

A)  J/°C 
B)  Jg/ °F 
C)  J/mole°C 
D)  g/°F 
E)  mole/°F 
A)  J/°C 
B)  Jg/ °F 
C)  J/mole°C 
D)  g/°F 
E)  mole/°F

Question 9

For a process at constant pressure,5350 joules are released.This quantity is equivalent to

Accepted Answer

A)  2.320 × 103 cal. 
B)  2.238 × 104 cal. 
C)  1.279 × 103 cal. 
D)  1.277 × 104 cal. 
E)  3.200 cal. 
A)  2.320 × 103 cal. 
B)  2.238 × 104 cal. 
C)  1.279 × 103 cal. 
D)  1.277 × 104 cal. 
E)  3.200 cal.

Question 10

Using the following equation for the combustion of octane,calculate the heat of reaction for 50.00 g of octane.The molar mass of octane is 114.33 g/mole. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O ΔH°rxn = -11018 kJ

Accepted Answer

A)  -2410 kJ 
B)  -2.410 kJ 
C)  -4820 kJ 
D)  -6300 kJ 
A)  -2410 kJ 
B)  -2.410 kJ 
C)  -4820 kJ 
D)  -6300 kJ

Question 11

Define molar heat capacity.

Accepted Answer

A)  the quantity of heat required to raise the temperature of 1 mole of a substance by 1°C 
B)  the quantity of heat required to change a system's temperature by 1°F 
C)  the quantity of heat required to raise the temperature of 1 gram of a substance by 1°C 
D)  the quantity of heat required to raise the temperature of 1 gram of a substance by 1°F 
E)  the quantity of heat required to lower the temperature of 1 liter of a substance by 1°C 
A)  the quantity of heat required to raise the temperature of 1 mole of a substance by 1°C 
B)  the quantity of heat required to change a system's temperature by 1°F 
C)  the quantity of heat required to raise the temperature of 1 gram of a substance by 1°C 
D)  the quantity of heat required to raise the temperature of 1 gram of a substance by 1°F 
E)  the quantity of heat required to lower the temperature of 1 liter of a substance by 1°C

Question 12

Define energy.

Accepted Answer

A)  the flow of energy caused by a chemical reaction 
B)  the flow of energy caused by a temperature difference 
C)  the result of a force acting through a distance 
D)  the capacity to do work 
E)  a chemical reaction 
A)  the flow of energy caused by a chemical reaction 
B)  the flow of energy caused by a temperature difference 
C)  the result of a force acting through a distance 
D)  the capacity to do work 
E)  a chemical reaction

Question 13

Which of the following is TRUE if ΔEsys = -100 J?

Accepted Answer

A)  The system is gaining 100 J, while the surroundings are losing 100 J. 
B)  The system is losing 100 J, while the surroundings are gaining 100 J. 
C)  Both the system and the surroundings are gaining 100 J. 
D)  Both the system and the surroundings are losing 100 J. 
E)  None of the above is true. 
A)  The system is gaining 100 J, while the surroundings are losing 100 J. 
B)  The system is losing 100 J, while the surroundings are gaining 100 J. 
C)  Both the system and the surroundings are gaining 100 J. 
D)  Both the system and the surroundings are losing 100 J. 
E)  None of the above is true.

Question 14

Which of the following signs on q and w represent a system that is doing work on the surroundings,as well as losing heat to the surroundings?

Accepted Answer

A)  q = -, w = - 
B)  q = +, w = + 
C)  q = -, w = + 
D)  q = +, w = - 
E)  None of these represent the system referenced above. 
A)  q = -, w = - 
B)  q = +, w = + 
C)  q = -, w = + 
D)  q = +, w = - 
E)  None of these represent the system referenced above.

Question 15

Identify the energy source with the highest negative ΔH°rxn.

Accepted Answer

A)  1 mole ethanol 
B)  1 mole methane 
C)  1 mole carbon 
D)  1 mole petroleum 
E)  All have the same value. 
A)  1 mole ethanol 
B)  1 mole methane 
C)  1 mole carbon 
D)  1 mole petroleum 
E)  All have the same value.

Question 16

The specific heat capacity of methane gas is 2.20 J/g-K.How many joules of heat are needed to raise the temperature of 5.00 g of methane from 22.0°C to 57.0°C?

Accepted Answer

A)  79.5 J 
B)  385 J 
C)  869 J 
D)  0.0126 J 
E)  28.5 J 
A)  79.5 J 
B)  385 J 
C)  869 J 
D)  0.0126 J 
E)  28.5 J

Question 17

Which of the following (with specific heat capacity provided)would show the smallest temperature change upon gaining 200.0 J of heat?

Accepted Answer

A)  50.0 g water, Cwater = 4.18|1.23 J/g°C 
B)  50.0 g Fe, CFe = 0.449 J/g°C 
C)  25.0 g granite, Cgranite = 0.79 J/g°C 
D)  25.0 g Pb, CPb = 0.128 J/g°C 
E)  25.0 g Ag, CAg= 0.235 J/g°C 
A)  50.0 g water, Cwater = 4.18|1.23 J/g°C 
B)  50.0 g Fe, CFe = 0.449 J/g°C 
C)  25.0 g granite, Cgranite = 0.79 J/g°C 
D)  25.0 g Pb, CPb = 0.128 J/g°C 
E)  25.0 g Ag, CAg= 0.235 J/g°C

Question 18

For ΔEsys to always be -,what must be TRUE?

Accepted Answer

A)  q = w 
B)  +q > -w 
C)  +w > -q 
D)  -w > +q 
A)  q = w 
B)  +q > -w 
C)  +w > -q 
D)  -w > +q

Question 19

The temperature rises from 25.00°C to 29.00°C in a bomb calorimeter when 3.50 g of sucrose undergoes combustion in a bomb calorimeter.Calculate ΔErxn for the combustion of sucrose in kJ/mol sucrose.The heat capacity of the calorimeter is 4.90 kJ/°C.The molar mass of sugar is 342.3 g/mol.

Accepted Answer

A)  -1.92 × 103 kJ/mole 
B)  1.92 × 103 kJ/mole 
C)  -1.23 × 103 kJ/mole 
D)  2.35 × 104 kJ/mole 
A)  -1.92 × 103 kJ/mole 
B)  1.92 × 103 kJ/mole 
C)  -1.23 × 103 kJ/mole 
D)  2.35 × 104 kJ/mole

Question 20

Define chemical energy.

Accepted Answer

Chemical energy is the energy

Exam 6: Thermochemistry

The specific heat capacity of liquid mercury is 0.14 J/gK.How many joules of heat are needed to raise the temperature of 7.25 g of mercury from 36.0°C to 75.0°C?

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: 4 SO3(g)→ 4 S(s)+ 6 O2(g)ΔH°rxn = ? Given: SO2(g)→ S(s)+ O2(g)ΔH°rxn = +296.8 kJ 2 SO2(g)+ O2(g)→ 2 SO3(g)ΔH°rxn = -197.8 kJ

When 0.500 mol of CH4(g)reacts with excess Cl2(g)at constant pressure according to the chemical equation shown below,354 kJ of heat are released.Calculate the value of ΔH for this reaction,as written. 2 CH4(g)+ 3 Cl2(g)→ 2 CHCl3(l)+ 3 H2(g)ΔH = ?

At 1 atm pressure,the heat of sublimation of gallium is 277 kJ/mol and the heat of vaporization is 271 kJ/mol.To the correct number of significant figures,how much heat is required to melt 3.50 mol of gallium at 1 atm pressure?

Calculate the amount of heat (in kJ)necessary to raise the temperature of 51.8 g benzene by 52.6 K.The specific heat capacity of benzene is 1.05 J/g°C.

Which of the following signs on q and w represent the surroundings that is doing work on the system,as well as gaining heat from the surroundings?

Identify the compound that is NOT a major air pollutant.

Give the units of heat capacity.

For a process at constant pressure,5350 joules are released.This quantity is equivalent to

Using the following equation for the combustion of octane,calculate the heat of reaction for 50.00 g of octane.The molar mass of octane is 114.33 g/mole. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O ΔH°rxn = -11018 kJ

Define molar heat capacity.

Define energy.

Which of the following is TRUE if ΔEsys = -100 J?

Which of the following signs on q and w represent a system that is doing work on the surroundings,as well as losing heat to the surroundings?

Identify the energy source with the highest negative ΔH°rxn.

The specific heat capacity of methane gas is 2.20 J/g-K.How many joules of heat are needed to raise the temperature of 5.00 g of methane from 22.0°C to 57.0°C?

Which of the following (with specific heat capacity provided)would show the smallest temperature change upon gaining 200.0 J of heat?

For ΔEsys to always be -,what must be TRUE?

The temperature rises from 25.00°C to 29.00°C in a bomb calorimeter when 3.50 g of sucrose undergoes combustion in a bomb calorimeter.Calculate ΔErxn for the combustion of sucrose in kJ/mol sucrose.The heat capacity of the calorimeter is 4.90 kJ/°C.The molar mass of sugar is 342.3 g/mol.

Define chemical energy.

Matter, measurement, and Problem Solving

Atoms and Elements

Molecules,compounds,and Chemical Equations

Chemical Quantities and Aqueous Reactions

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,

Liquids,solids,and Intermolecular Forces

Solids and Modern Materials

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

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Free Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

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Use the standard reaction enthalpies given below to determine ΔH°_rxn for the following reaction: 4 SO₃(g)→ 4 S(s)+ 6 O₂(g)ΔH°_rxn= ? Given: SO₂(g)→ S(s)+ O₂(g)ΔH°_rxn= +296.8 kJ 2 SO₂(g)+ O₂(g)→ 2 SO₃(g)ΔH°_rxn= -197.8 kJ

When 0.500 mol of CH₄(g)reacts with excess Cl₂(g)at constant pressure according to the chemical equation shown below,354 kJ of heat are released.Calculate the value of ΔH for this reaction,as written. 2 CH₄(g)+ 3 Cl₂(g)→ 2 CHCl₃(l)+ 3 H₂(g)ΔH = ?

Using the following equation for the combustion of octane,calculate the heat of reaction for 50.00 g of octane.The molar mass of octane is 114.33 g/mole. 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O ΔH°_rxn= -11018 kJ

Which of the following is TRUE if ΔE_sys = -100 J?

Identify the energy source with the highest negative ΔH°_rxn.

For ΔE_systo always be -,what must be TRUE?

The temperature rises from 25.00°C to 29.00°C in a bomb calorimeter when 3.50 g of sucrose undergoes combustion in a bomb calorimeter.Calculate ΔE_rxn for the combustion of sucrose in kJ/mol sucrose.The heat capacity of the calorimeter is 4.90 kJ/°C.The molar mass of sugar is 342.3 g/mol.