Question 1

When the reaction below is performed in a water bath,will the temperature of the water bath increase or decrease?
432 kJ + A + 2 B → 3 C

Accepted Answer

The answer of When the reaction below is performed in...

Question 2

Is thermal energy a form of kinetic or potential molecular energy?

Accepted Answer

The answer of Is thermal energy a form of kinetic...

Question 3

A reaction that absorbs 49.6 kJ from the surroundings in a vessel that undergoes a volume decrease of 1.25 L at a constant 4.00 atm pressure has an energy change,ΔE = ________ kJ.

Accepted Answer

The answer of A reaction that absorbs 49.6 kJ from...

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.How much heat is required to melt 0.500 mol of gallium at 1.00 atm pressure?

Accepted Answer

A) 6.00 kJ 
B) 3.00 kJ 
C) 268 kJ 
D) 271 kJ 
A) 6.00 kJ 
B) 3.00 kJ 
C) 268 kJ 
D) 271 kJ

Question 5

Two metals of equal mass with different heat capacities are subjected to the same amount of heat.Which undergoes the smallest change in temperature?

Accepted Answer

A) The metal with the highest heat capacity. 
B) The metal with the lowest heat capacity. 
C) Both undergo the same change in temperature. 
D) You need to know the initial temperatures of both metals. 
A) The metal with the highest heat capacity. 
B) The metal with the lowest heat capacity. 
C) Both undergo the same change in temperature. 
D) You need to know the initial temperatures of both metals.

Question 6

The SI unit for energy is the ________.

Accepted Answer

The answer of The SI unit for energy is the...

Question 7

At a given temperature and pressure,which of the following would be expected to have the greatest molar entropy?

Accepted Answer

A) F2 (s) 
B) F2 (l) 
C) F2 (g) 
D) All of these would be expected to have the same molar entropy. 
A) F2 (s) 
B) F2 (l) 
C) F2 (g) 
D) All of these would be expected to have the same molar entropy.

Question 8

How much heat is transferred per 5.00 moles of NH3(g)formed in the reaction shown below? N2(g)+ 3 H2(g)→ 2 NH3(g)ΔH° = - 92.2 kJ

Accepted Answer

A) 92.2 kJ 
B) 230 kJ 
C) 461 kJ 
D) 154 kJ 
A) 92.2 kJ 
B) 230 kJ 
C) 461 kJ 
D) 154 kJ

Question 9

Which of the following is not true?

Accepted Answer

A) A spontaneous reaction need not occur immediately. 
B) A spontaneous reaction must be exothermic and must have an increase in entropy. 
C) The reverse of a nonspontaneous reaction is always spontaneous. 
D) A spontaneous reaction is one that can proceed on its own. 
A) A spontaneous reaction need not occur immediately. 
B) A spontaneous reaction must be exothermic and must have an increase in entropy. 
C) The reverse of a nonspontaneous reaction is always spontaneous. 
D) A spontaneous reaction is one that can proceed on its own.

Question 10

When 8.00 g of Ba(s)is added to 100.00 g of water in a container open to the atmosphere,the reaction shown below occurs and the temperature of the resulting solution rises from 22.00°C to 77.62°C.If the specific heat of the solution is 4.18 J/(g ∙ °C),calculate ΔH for the reaction,as written. Ba(s)+ 2 H2O(l)→ Ba(OH)2(aq)+ H2(g)ΔH = ?

Accepted Answer

A) -431 kJ 
B) -3.14 kJ 
C) 3.14 kJ 
D) 431 kJ 
A) -431 kJ 
B) -3.14 kJ 
C) 3.14 kJ 
D) 431 kJ

Question 11

Determine the sign of ΔS° for each of the following: I.The mixing of two gases at a given temperature and pressure
II.C(s)+ 2 H2O(g)→ CO2(g)+ 2 H2(g)

Accepted Answer

A) ΔS° is negative for I and negative for II. 
B) ΔS° is negative for I and positive for II. 
C) ΔS° is positive for I and negative for II. 
D) ΔS° is positive for I and positive for II. 
A) ΔS° is negative for I and negative for II. 
B) ΔS° is negative for I and positive for II. 
C) ΔS° is positive for I and negative for II. 
D) ΔS° is positive for I and positive for II.

Question 12

For an explosion in an open vessel,one would expect

Accepted Answer

A) ΔH to be positive and ΔE to be less than ΔH. 
B) ΔH to be positive and ΔE to be greater than ΔH. 
C) ΔH to be negative and ΔE to be less than ΔH. 
D) ΔH to be negative and ΔE to be greater than ΔH. 
A) ΔH to be positive and ΔE to be less than ΔH. 
B) ΔH to be positive and ΔE to be greater than ΔH. 
C) ΔH to be negative and ΔE to be less than ΔH. 
D) ΔH to be negative and ΔE to be greater than ΔH.

Question 13

The product,Z,is represented by

Accepted Answer

A) arrow A. 
B) line D. 
C) line E. 
D) line F. 
A) arrow A. 
B) line D. 
C) line E. 
D) line F.

Question 14

For the reaction: A + 2 B → 3 C,ΔH° = -203 kJ.For the reaction 12 C → 4 A + 8 B,ΔH° = ________ kJ.

Accepted Answer

The answer of For the reaction: A + 2 B...

Question 15

When 2.00 mol of benzene is vaporized at a constant pressure of 1.00 atm and at its normal boiling point of 80.1°C,67.8 kJ are absorbed and PΔV for the vaporization process is equal to 5.80 kJ then

Accepted Answer

A) ΔE = 62.0 kJ and ΔH = 67.8 kJ. 
B) ΔE = 73.6 kJ and ΔH = 67.8 kJ. 
C) ΔE = 67.8 kJ and ΔH = 73.6 kJ. 
D) ΔE = 67.8 kJ and ΔH = 62.0 kJ. 
A) ΔE = 62.0 kJ and ΔH = 67.8 kJ. 
B) ΔE = 73.6 kJ and ΔH = 67.8 kJ. 
C) ΔE = 67.8 kJ and ΔH = 73.6 kJ. 
D) ΔE = 67.8 kJ and ΔH = 62.0 kJ.

Question 16

At constant pressure for the reaction shown below,what can be said about PΔV and ΔE? N2(g)+ 3 H2(g)→ 2 NH3(g)ΔH° = - 92.2 kJ

Accepted Answer

A) PΔV > 0 and ΔE > -92.2 kJ B) PΔV > 0 and ΔE -92.2 kJ D) PΔV < 0 and ΔE < -92.2 kJ A) PΔV > 0 and ΔE > -92.2 kJ B) PΔV > 0 and ΔE -92.2 kJ D) PΔV < 0 and ΔE < -92.2 kJ

Question 17

The reaction 4 Ag(s)+ O2(g)→ 2 Ag2O(s)favors Ag2O at low temperature,but it favors Ag and O2 at high temperatures.How can this be explained in terms of ΔH and ΔS?

Accepted Answer

A) ΔH is negative and ΔS is negative. 
B) ΔH is negative and ΔS is positive. 
C) ΔH is positive and ΔS is negative. 
D) ΔH is positive and ΔS is positive. 
A) ΔH is negative and ΔS is negative. 
B) ΔH is negative and ΔS is positive. 
C) ΔH is positive and ΔS is negative. 
D) ΔH is positive and ΔS is positive.

Question 18

Use the given standard enthalpies of formation to calculate ΔH° for the following reaction 3 Fe2O3(s)+ CO(g)→ 2 Fe3O4(s)+ CO2(g).

Accepted Answer

A) -5213.4 kJ 
B) -577.2 kJ 
C) -47.2 kJ 
D) +47.2 kJ 
A) -5213.4 kJ 
B) -577.2 kJ 
C) -47.2 kJ 
D) +47.2 kJ

Question 19

-What are the signs of ΔH and ΔS for the reaction represented in the above drawing?

Accepted Answer

A) ΔH = +,ΔS = + 
B) ΔH = +,ΔS = - 
C) ΔH = -,ΔS = + 
D) ΔH = -,ΔS = - 
A) ΔH = +,ΔS = + 
B) ΔH = +,ΔS = - 
C) ΔH = -,ΔS = + 
D) ΔH = -,ΔS = -

Question 20

Find ΔH for BaCO3 (s)→ BaO (s)+ CO2 (g) given 2 Ba (s)+ O2 (g)→ 2 BaO (s)ΔH = -1107.0 kJ
Ba (s)+ CO2 (g)+ 1/2 O2 (g)→ BaCO3 (s)ΔH = -822.5 kJ

Accepted Answer

A) -1929.5 kJ 
B) +1376 kJ 
C) -269.0 kJ 
D) 269.0 kJ 
A) -1929.5 kJ 
B) +1376 kJ 
C) -269.0 kJ 
D) 269.0 kJ

Exam 9: Thermochemistry: Chemical Energy

When the reaction below is performed in a water bath,will the temperature of the water bath increase or decrease? 432 kJ + A + 2 B → 3 C

Is thermal energy a form of kinetic or potential molecular energy?

A reaction that absorbs 49.6 kJ from the surroundings in a vessel that undergoes a volume decrease of 1.25 L at a constant 4.00 atm pressure has an energy change,ΔE = ________ kJ.

At 1 atm pressure the heat of sublimation of gallium is 277 kJ/mol and the heat of vaporization is 271 kJ/mol.How much heat is required to melt 0.500 mol of gallium at 1.00 atm pressure?

Two metals of equal mass with different heat capacities are subjected to the same amount of heat.Which undergoes the smallest change in temperature?

The SI unit for energy is the ________.

At a given temperature and pressure,which of the following would be expected to have the greatest molar entropy?

How much heat is transferred per 5.00 moles of NH3(g)formed in the reaction shown below? N2(g)+ 3 H2(g)→ 2 NH3(g)ΔH° = - 92.2 kJ

Which of the following is not true?

Determine the sign of ΔS° for each of the following: I.The mixing of two gases at a given temperature and pressure II.C(s)+ 2 H2O(g)→ CO2(g)+ 2 H2(g)

For an explosion in an open vessel,one would expect

The product,Z,is represented by

For the reaction: A + 2 B → 3 C,ΔH° = -203 kJ.For the reaction 12 C → 4 A + 8 B,ΔH° = ________ kJ.

When 2.00 mol of benzene is vaporized at a constant pressure of 1.00 atm and at its normal boiling point of 80.1°C,67.8 kJ are absorbed and PΔV for the vaporization process is equal to 5.80 kJ then

At constant pressure for the reaction shown below,what can be said about PΔV and ΔE? N2(g)+ 3 H2(g)→ 2 NH3(g)ΔH° = - 92.2 kJ

The reaction 4 Ag(s)+ O2(g)→ 2 Ag2O(s)favors Ag2O at low temperature,but it favors Ag and O2 at high temperatures.How can this be explained in terms of ΔH and ΔS?

Use the given standard enthalpies of formation to calculate ΔH° for the following reaction 3 Fe2O3(s)+ CO(g)→ 2 Fe3O4(s)+ CO2(g).

-What are the signs of ΔH and ΔS for the reaction represented in the above drawing?

Find ΔH for BaCO3 (s)→ BaO (s)+ CO2 (g) given 2 Ba (s)+ O2 (g)→ 2 BaO (s)ΔH = -1107.0 kJ Ba (s)+ CO2 (g)+ 1/2 O2 (g)→ BaCO3 (s)ΔH = -822.5 kJ

Chemical Tools: Experimentation and Measurement

Atoms, molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Periodicity and the Electronic Structure of Atoms

Ionic Compounds: Periodic Trends and Bonding

Covalent Bonding and Electron-Dot Structures

Covalent Compounds: Bonding Theories and Molecular Structure

Gases: Their Properties and Behavior

Liquids, solids, and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Electrochemistry

Nuclear Chemistry

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

The Main-Group Elements

Connections to Organic and Biological Chemistry

Filters

How much heat is transferred per 5.00 moles of NH₃(g)formed in the reaction shown below? N₂(g)+ 3 H₂(g)→ 2 NH₃(g)ΔH° = - 92.2 kJ

Determine the sign of ΔS° for each of the following: I.The mixing of two gases at a given temperature and pressure II.C(s)+ 2 H₂O(g)→ CO₂(g)+ 2 H₂(g)

At constant pressure for the reaction shown below,what can be said about PΔV and ΔE? N₂(g)+ 3 H₂(g)→ 2 NH₃(g)ΔH° = - 92.2 kJ

The reaction 4 Ag(s)+ O₂(g)→ 2 Ag₂O(s)favors Ag₂O at low temperature,but it favors Ag and O₂ at high temperatures.How can this be explained in terms of ΔH and ΔS?

Use the given standard enthalpies of formation to calculate ΔH° for the following reaction 3 Fe₂O₃(s)+ CO(g)→ 2 Fe₃O₄(s)+ CO₂(g).

Find ΔH for BaCO₃ (s)→ BaO (s)+ CO₂ (g) given 2 Ba (s)+ O₂ (g)→ 2 BaO (s)ΔH = -1107.0 kJ Ba (s)+ CO₂ (g)+ 1/2 O₂ (g)→ BaCO₃ (s)ΔH = -822.5 kJ