Question 1

For all processes, both q and w will have the same sign.

Accepted Answer

A) True 
 B)False

Question 2

A) Starting from the equation H = E + PV, show how the relationship $\Delta$H = qp is derived. Clearly indicate any necessary assumptions or conditions.
B) In one sentence, state in full what is meant by the equation: $\Delta$H = qp.

Accepted Answer

a. Since H = E + PV (defining equation f

Question 3

The dissolution of barium hydroxide in water is an exothermic process. Which of the following statements is correct?

Accepted Answer

A)  The enthalpy of solid barium hydroxide plus pure water is less than that of the solution, at the same temperature. 
B)  The enthalpy of solid barium hydroxide plus pure water is greater than that of the solution, at the same temperature. 
C)  The enthalpy of solid barium hydroxide plus pure water is the same as that of the solution, at the same temperature. 
D)  The temperature of the solution is lower than of the barium hydroxide and water before mixing. 
E)  When barium hydroxide dissolves in water, the system does work on the surroundings. 
A)  The enthalpy of solid barium hydroxide plus pure water is less than that of the solution, at the same temperature. 
B)  The enthalpy of solid barium hydroxide plus pure water is greater than that of the solution, at the same temperature. 
C)  The enthalpy of solid barium hydroxide plus pure water is the same as that of the solution, at the same temperature. 
D)  The temperature of the solution is lower than of the barium hydroxide and water before mixing. 
E)  When barium hydroxide dissolves in water, the system does work on the surroundings.

Question 4

Which one of the following equations represents the formation reaction of CH3OH(l)?

Accepted Answer

A)  C(g) + 2H2(g) + ½O2(g) $\rightarrow$CH3OH(l) 
B)  C(g) + 4H(g) + O(g) $\rightarrow$CH3OH(l) 
C)  C(graphite) + 4H(g) + O(g) $\rightarrow$ CH3OH(l) 
D)  C(diamond) + 4H(g) + O(g) $\rightarrow$CH3OH(l) 
E)  C(graphite) + 2H2(g) + ½O2(g) $\rightarrow$CH3OH(l) 
A)  C(g) + 2H2(g) + ½O2(g) $\rightarrow$CH3OH(l) 
B)  C(g) + 4H(g) + O(g) $\rightarrow$CH3OH(l) 
C)  C(graphite) + 4H(g) + O(g) $\rightarrow$ CH3OH(l) 
D)  C(diamond) + 4H(g) + O(g) $\rightarrow$CH3OH(l) 
E)  C(graphite) + 2H2(g) + ½O2(g) $\rightarrow$CH3OH(l)

Question 5

An important step in the synthesis of nitric acid is the conversion of ammonia to nitric oxide.   Calculate $\Delta$H $\degree$rxn for this reaction. $\Delta$H $\degree$f [NH3(g)] = -45.9 kJ/mol; $\Delta$H $\degree$f [NO(g)] = 90.3 kJ/mol; $\Delta$H $\degree$f [H2O(g)] = -241.8 kJ/mol.

Accepted Answer

A)  -906.0 kJ 
B)  -197.4 kJ 
C)  -105.6 kJ 
D)  197.4 kJ 
E)  906.0 kJ 
A)  -906.0 kJ 
B)  -197.4 kJ 
C)  -105.6 kJ 
D)  197.4 kJ 
E)  906.0 kJ

Question 6

A backpacker collects snow at 0 $\degree$C, and places it in a cooking pot on a camp stove. It takes 643 kJ of heat energy to melt the snow and bring the water to boiling. Assuming no heat loss, and neglecting the specific heat capacity of the pot, calculate the mass of snow that the backpacker collected. (Data: specific heat capacity of liquid water, c = 4.18 J/g ? K; and H2O(s) $\rightarrow$H2O(l) $\Delta$H = $\Delta$Hfusion = 6.02 kJ/mol)

Accepted Answer

A)  1.92 kg 
B)  1.90 kg 
C)  1.52 kg 
D)  855 g 
E)  < 800 g 
A)  1.92 kg 
B)  1.90 kg 
C)  1.52 kg 
D)  855 g 
E)  < 800 g

Question 7

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g-K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132$\degree$C to 85$\degree$C.

Accepted Answer

A)  -1900 kJ 
B)  -420 kJ 
C)  -99 kJ 
D)  -0.42 kJ 
E)  -4.2 *10¯6 kJ 
A)  -1900 kJ 
B)  -420 kJ 
C)  -99 kJ 
D)  -0.42 kJ 
E)  -4.2 *10¯6 kJ

Question 8

The enthalpy (H) of liquid water is greater than that of the same quantity of ice at the same temperature.

Accepted Answer

A) True 
 B)False

Question 9

Galena is the ore from which elemental lead is extracted. In the first step of the extraction process, galena is heated in air to form lead(II) oxide.   What mass of galena is converted to lead oxide if 975 kJ of heat are liberated?

Accepted Answer

A)  203 g 
B)  282 g 
C)  406 g 
D)  478 g 
E)  564 g 
A)  203 g 
B)  282 g 
C)  406 g 
D)  478 g 
E)  564 g

Question 10

40.0 g of ice cubes at 0.0 $\degree$C are combined with 150. g of liquid water at 20.0 $\degree$C in a coffee cup calorimeter. Calculate the final temperature reached, assuming no heat loss or gain from the surroundings. (Data: specific heat capacity of H2O(l), c = 4.18 J/g- $\degree$C; H2O(s) $\rightarrow$ H2O(l) $\Delta$H = 6.02 kJ/mol)

Accepted Answer

A)  0.0 
B)  10.6 
C)  30.7 
D)  43.2 
E)  56.4 
A)  0.0 
B)  10.6 
C)  30.7 
D)  43.2 
E)  56.4

Question 11

and has work done on it by the surroundings has:

Accepted Answer

A)  w = $\Delta$E 
B)  w = -$\Delta$E 
C)  w > 0, $\Delta$E  0 
E)  w > $\Delta$E 
A)  w = $\Delta$E 
B)  w = -$\Delta$E 
C)  w > 0, $\Delta$E  0 
E)  w > $\Delta$E

Question 12

Calculate q when 28.6 g of water is heated from 22.0$\degree$C to 78.3$\degree$C.

Accepted Answer

A)  0.385 kJ 
B)  1.61 kJ 
C)  6.74 kJ 
D)  9.37 kJ 
E)  1.61 * 103 kJ 
A)  0.385 kJ 
B)  1.61 kJ 
C)  6.74 kJ 
D)  9.37 kJ 
E)  1.61 * 103 kJ

Question 13

Which one of the following statements about standard states is incorrect?

Accepted Answer

A)  The standard state of a solid compound is the pure solid. 
B)  The standard state of a liquid compound is the pure liquid. 
C)  The standard state of a gaseous compound is the gas at a pressure of 1 atmosphere. 
D)  The standard state of an aqueous solute is a saturated solution in water. 
E)  The standard state of an element is the form in which it is stable at 1 atm and a specified temperature, usually 25$\degree$C. 
A)  The standard state of a solid compound is the pure solid. 
B)  The standard state of a liquid compound is the pure liquid. 
C)  The standard state of a gaseous compound is the gas at a pressure of 1 atmosphere. 
D)  The standard state of an aqueous solute is a saturated solution in water. 
E)  The standard state of an element is the form in which it is stable at 1 atm and a specified temperature, usually 25$\degree$C.

Question 14

What is the final temperature when 20.0 g of water at 25$\degree$C is mixed with 30.0 g of water at 80$\degree$C?

Accepted Answer

A)  35$\degree$C 
B)  42$\degree$C 
C)  53$\degree$C 
D)  58$\degree$C 
E)  70$\degree$C 
A)  35$\degree$C 
B)  42$\degree$C 
C)  53$\degree$C 
D)  58$\degree$C 
E)  70$\degree$C

Question 15

Nitric acid, which is among the top 15 chemicals produced in the United States, was first prepared over 1200 years ago by heating naturally occurring sodium nitrate (called saltpeter) with sulfuric acid and collecting the vapors produced. Calculate $\Delta$H$\degree$ffor this reaction. 
$\Delta$H$\degree$f [NaNO3(s)] = -467.8 kJ/mol; $\Delta$H $\degree$f[NaHSO4(s)] = -1125.5 kJ/mol; $\Delta$H $\degree$f[H2SO4(l) = -814.0 kJ/mol; $\Delta$H $\degree$f[HNO3(g)] = -135.1 kJ/mol. NaNO3(s) + H2SO4(l) $\rightarrow$NaHSO4(s) + HNO3(g)

Accepted Answer

A)  -644.2 kJ 
B)  -291.4 kJ 
C)  -21.2 kJ 
D)  21.2 kJ 
E)  644.2 kJ 
A)  -644.2 kJ 
B)  -291.4 kJ 
C)  -21.2 kJ 
D)  21.2 kJ 
E)  644.2 kJ

Question 16

The specific heat capacity c of a metal is approximately related to its molar mass ? as follows: c * ? = 3R, where R is the universal gas constant, 8.314 J/mol-K. Use this relationship to identify the metal which has a specific heat capacity of 0.900 J/g ? K.

Accepted Answer

A)  Li 
B)  Sn 
C)  Ca 
D)  Al 
E)  U 
A)  Li 
B)  Sn 
C)  Ca 
D)  Al 
E)  U

Question 17

In which one of the following reactions would you expect $\Delta$H to be substantially greater than $\Delta$E (i.e., $\Delta$H > $\Delta$E)?

Accepted Answer

A)  H2(g) + Br2(g) $\rightarrow$ 2HBr(g) 
B)  CO2(s)$\rightarrow$CO2(g) 
C)  C2H2(g) + H2(g) $\rightarrow$C2H4(g) 
D)  H2O(s) $\rightarrow$ H2O(l) 
E)  HCl(aq) + NaOH(aq) $\rightarrow$NaCl(aq) + H2O(l) 
A)  H2(g) + Br2(g) $\rightarrow$ 2HBr(g) 
B)  CO2(s)$\rightarrow$CO2(g) 
C)  C2H2(g) + H2(g) $\rightarrow$C2H4(g) 
D)  H2O(s) $\rightarrow$ H2O(l) 
E)  HCl(aq) + NaOH(aq) $\rightarrow$NaCl(aq) + H2O(l)

Question 18

Two solutions (the system), each of 25.0 mL volume and at 25.0$\degree$C, are mixed in a beaker. A reaction occurs between them, and the temperature rises to 35.0$\degree$C. After the products have equilibrated with the surroundings, the temperature is again 25.0$\degree$C and the total volume is 50.0 mL. No gases are involved in the reaction. Which one of the following relationships concerning the change from initial to final states (both at 25.0$\degree$C) is correct?

Accepted Answer

A)  ($\Delta$E = 0) 
B)  ($\Delta$H = 0) 
C)  ($\Delta$E > 0) 
D)  q = 0 
E)  w = 0 
A)  ($\Delta$E = 0) 
B)  ($\Delta$H = 0) 
C)  ($\Delta$E > 0) 
D)  q = 0 
E)  w = 0

Question 19

A Snickers$\rightarrow$candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

Accepted Answer

A)  5.0 *10¯1 kJ 
B)  29 kJ 
C)  5.0 *102 kJ 
D)  1.2 * 103 kJ 
E)  5.0 * 105 kJ 
A)  5.0 *10¯1 kJ 
B)  29 kJ 
C)  5.0 *102 kJ 
D)  1.2 * 103 kJ 
E)  5.0 * 105 kJ

Question 20

Calculate the $\Delta$H$\degree$rxn for the following reaction. ($\Delta$H$\degree$f [SiO2(s)] = -910.9 kJ/mol; $\Delta$H$\degree$f [SiCl4(g)] = -657.0 kJ/mol; $\Delta$H$\degree$f [HCl(g)] = -92.3 kJ/mol; $\Delta$H$\degree$f [H2O (g)] = -241.8 kJ/mol)

Accepted Answer

A)  -139.5 kJ 
B)  -137.4 kJ 
C)  -104.4 kJ 
D)  104.4 kJ 
E)  139.5 kJ 
A)  -139.5 kJ 
B)  -137.4 kJ 
C)  -104.4 kJ 
D)  104.4 kJ 
E)  139.5 kJ

For all processes, both q and w will have the same sign.

A) Starting from the equation H = E + PV, show how the relationship $\Delta$ H = q_p is derived. Clearly indicate any necessary assumptions or conditions. B) In one sentence, state in full what is meant by the equation: $\Delta$ H = q_p.

The dissolution of barium hydroxide in water is an exothermic process. Which of the following statements is correct?

Which one of the following equations represents the formation reaction of CH₃OH(l)?

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g-K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132 $\degree$ C to 85 $\degree$ C.

The enthalpy (H) of liquid water is greater than that of the same quantity of ice at the same temperature.

Galena is the ore from which elemental lead is extracted. In the first step of the extraction process, galena is heated in air to form lead(II) oxide. What mass of galena is converted to lead oxide if 975 kJ of heat are liberated?

and has work done on it by the surroundings has:

Calculate q when 28.6 g of water is heated from 22.0 $\degree$ C to 78.3 $\degree$ C.

Which one of the following statements about standard states is incorrect?

What is the final temperature when 20.0 g of water at 25 $\degree$ C is mixed with 30.0 g of water at 80 $\degree$ C?

The specific heat capacity c of a metal is approximately related to its molar mass ? as follows: c * ? = 3R, where R is the universal gas constant, 8.314 J/mol-K. Use this relationship to identify the metal which has a specific heat capacity of 0.900 J/g ? K.

In which one of the following reactions would you expect $\Delta$ H to be substantially greater than $\Delta$ E (i.e., $\Delta$ H > $\Delta$ E)?

A Snickers^{$\rightarrow$}candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Exam 6: Thermochemistry: Energy Flow and Chemical Change

For all processes, both q and w will have the same sign.

A) Starting from the equation H = E + PV, show how the relationship Δ\DeltaΔ H = qp is derived. Clearly indicate any necessary assumptions or conditions. B) In one sentence, state in full what is meant by the equation: Δ\DeltaΔ H = qp.

The dissolution of barium hydroxide in water is an exothermic process. Which of the following statements is correct?

Which one of the following equations represents the formation reaction of CH3OH(l)?

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g-K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132 °\degree° C to 85 °\degree° C.

The enthalpy (H) of liquid water is greater than that of the same quantity of ice at the same temperature.

Galena is the ore from which elemental lead is extracted. In the first step of the extraction process, galena is heated in air to form lead(II) oxide. What mass of galena is converted to lead oxide if 975 kJ of heat are liberated?

and has work done on it by the surroundings has:

Calculate q when 28.6 g of water is heated from 22.0 °\degree° C to 78.3 °\degree° C.

Which one of the following statements about standard states is incorrect?

What is the final temperature when 20.0 g of water at 25 °\degree° C is mixed with 30.0 g of water at 80 °\degree° C?

The specific heat capacity c of a metal is approximately related to its molar mass ? as follows: c * ? = 3R, where R is the universal gas constant, 8.314 J/mol-K. Use this relationship to identify the metal which has a specific heat capacity of 0.900 J/g ? K.

In which one of the following reactions would you expect Δ\DeltaΔ H to be substantially greater than Δ\DeltaΔ E (i.e., Δ\DeltaΔ H > Δ\DeltaΔ E)?

A Snickers →\rightarrow→ candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

Calculate the Δ\DeltaΔ H °\degree° rxn for the following reaction. ( Δ\DeltaΔ H °\degree° f [SiO2(s)] = -910.9 kJ/mol; Δ\DeltaΔ H °\degree° f [SiCl4(g)] = -657.0 kJ/mol; Δ\DeltaΔ H °\degree° f [HCl(g)] = -92.3 kJ/mol; Δ\DeltaΔ H °\degree° f [H2O (g)] = -241.8 kJ/mol)

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

A) Starting from the equation H = E + PV, show how the relationship $\Delta$ H = q_p is derived. Clearly indicate any necessary assumptions or conditions. B) In one sentence, state in full what is meant by the equation: $\Delta$ H = q_p.

Which one of the following equations represents the formation reaction of CH₃OH(l)?

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g-K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132 $\degree$ C to 85 $\degree$ C.

Calculate q when 28.6 g of water is heated from 22.0 $\degree$ C to 78.3 $\degree$ C.

What is the final temperature when 20.0 g of water at 25 $\degree$ C is mixed with 30.0 g of water at 80 $\degree$ C?

In which one of the following reactions would you expect $\Delta$ H to be substantially greater than $\Delta$ E (i.e., $\Delta$ H > $\Delta$ E)?

A Snickers^{$\rightarrow$}candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?