Question 1

Which of the following statements is TRUE?

Accepted Answer

A)  State functions do not depend on the path taken to arrive at a particular state. 
B)  DErxn can be determined using constant volume calorimetry. 
C)  Energy is neither created nor destroyed, excluding nuclear reactions. 
D)  ΔHrxn can be determined using constant pressure calorimetry. 
E)  All of the above are true. 
A)  State functions do not depend on the path taken to arrive at a particular state. 
B)  DErxn can be determined using constant volume calorimetry. 
C)  Energy is neither created nor destroyed, excluding nuclear reactions. 
D)  ΔHrxn can be determined using constant pressure calorimetry. 
E)  All of the above are true. E

Question 2

At 1 atm pressure,the heat of sublimation of gallium is 277.0kJ/mol and the heat of vaporization is 271.0 kJ/mol.To the correct number of significant figures,how much heat is required to melt 5.50 mol of gallium at 1 atm pressure?

Accepted Answer

A)  6 kJ 
B)  33 kJ 
C)  244 kJ 
D)  274 kJ 
A)  6 kJ 
B)  33 kJ 
C)  244 kJ 
D)  274 kJ B

Question 3

It takes 18.2 kJ of energy to raise the temperature of 55.2g of an unknown liquid from 30.0°C to 47.0°C.What is the specific heat of the unknown liquid

Accepted Answer

A)  1. 17 J/(g ∙ °
C)  
B)  205J/(g ∙ °
C)  
C)  89.0 J/(g ∙ °
C)  
D)  19.4 J/(g ∙ °
C)  
A)  1. 17 J/(g ∙ °
C)  
B)  205J/(g ∙ °
C)  
C)  89.0 J/(g ∙ °
C)  
D)  19.4 J/(g ∙ °
C)  D

Question 4

Where does the energy absorbed during an endothermic reaction go?

Accepted Answer

During an endothermic reaction,the produ

Question 5

Which of the following processes are endothermic?

Accepted Answer

A)  the reaction associated with the lattice energy of LiCl 
B)  the reaction associated with the ionization energy of potassium 
C)  the reaction associated with the heat of formation of CaS 
D)  the formation of F2 from its elements in their standard states 
E)  None of the above are endothermic. 
A)  the reaction associated with the lattice energy of LiCl 
B)  the reaction associated with the ionization energy of potassium 
C)  the reaction associated with the heat of formation of CaS 
D)  the formation of F2 from its elements in their standard states 
E)  None of the above are endothermic.

Question 6

When 10.00 moles of H2(g)reacts with 5.000 mol of O2(g)to form 10.00 mol of H2O(l)at 25°C and a constant pressure of 1.00 atm.If 683.0 kJ of heat are released during this reaction,and PΔV is equal to -37.00 kJ,then

Accepted Answer

A)  ΔH° = +683.0 kJ and ΔE° = +720.0 kJ. 
B)  ΔH° = +683.0 kJ and ΔE° = +646.0 kJ. 
C)  ΔH° = -683.0 kJ and ΔE° = -646.0 kJ. 
D)  ΔH° = -683.0 kJ and ΔE° = -720.0 kJ. 
A)  ΔH° = +683.0 kJ and ΔE° = +720.0 kJ. 
B)  ΔH° = +683.0 kJ and ΔE° = +646.0 kJ. 
C)  ΔH° = -683.0 kJ and ΔE° = -646.0 kJ. 
D)  ΔH° = -683.0 kJ and ΔE° = -720.0 kJ.

Question 7

Choose the reaction that illustrates ΔH°f for Mg(NO3)2.

Accepted Answer

A)  Mg(s) + N2(g) + 3O2(g) → Mg(NO3)2(s) 
B)  Mg2+(aq) + 2 NO3-(aq) → Mg(NO3)2(aq) 
C)  Mg(s) + 2 N(g) + 6 O(g) → Mg(NO3)2(s) 
D)  Mg(NO3)2(aq) → Mg2+(aq) + 2 NO3-(aq) 
E)  Mg(NO3)2(s) → Mg(s) + N2(g) + 3O2(g) 
A)  Mg(s) + N2(g) + 3O2(g) → Mg(NO3)2(s) 
B)  Mg2+(aq) + 2 NO3-(aq) → Mg(NO3)2(aq) 
C)  Mg(s) + 2 N(g) + 6 O(g) → Mg(NO3)2(s) 
D)  Mg(NO3)2(aq) → Mg2+(aq) + 2 NO3-(aq) 
E)  Mg(NO3)2(s) → Mg(s) + N2(g) + 3O2(g)

Question 8

What is the enthalpy change (in kJ)of a chemical reaction that raises the temperature of 250.0 mL of solution having a density of 1.25 g/ml by 7.80°C? (The specific heat of the solution is 3.74 J/g∙K.)

Accepted Answer

A)  -7.43 kJ 
B)  -12.51 kJ 
C)  8.20 kJ 
D)  -9.12 kJ 
E)  6.51 kJ 
A)  -7.43 kJ 
B)  -12.51 kJ 
C)  8.20 kJ 
D)  -9.12 kJ 
E)  6.51 kJ

Question 9

The combustion of titanium with oxygen produces titanium dioxide: Ti(s)+   (g)→   (s)
When 2.060 g of titanium is combusted in a bomb calorimeter,the temperature of the calorimeter increases from 25.00°C to 91.60°C.In a separate experiment,the heat capacity of the calorimeter is measured to be 9.84 kJ/K.The heat of reaction for the combustion of a mole of Ti in this calorimeter is ________ kJ/mol.

Accepted Answer

A)  14.3 
B)  19.6 
C)  -311 
D)  -0.154 
E)  -1.52 ×   
A)  14.3 
B)  19.6 
C)  -311 
D)  -0.154 
E)  -1.52 ×

Question 10

Give the units of heat capacity.

Accepted Answer

A)  J/°C 
B)  J/g °C 
C)  Jmole/°C 
D)  g/°C 
E)  mole/°C 
A)  J/°C 
B)  J/g °C 
C)  Jmole/°C 
D)  g/°C 
E)  mole/°C

Question 11

Which one of the following elements is NOT in its standard state?

Accepted Answer

A)  Br2(g) 
B)  F2(g) 
C)  Hg(l) 
D)  Na(s) 
E)  Cl2(g) 
A)  Br2(g) 
B)  F2(g) 
C)  Hg(l) 
D)  Na(s) 
E)  Cl2(g)

Question 12

If a block of gold requires 1.42 kJ of energy to raise the temperature from 120.0°C to 240.0°C,what is the mass of the block? The specific heat capacity of gold is 0.129 J/g-K.

Accepted Answer

A)  92.0 g 
B)  35.3 g 
C)  186 g 
D)  55.7 g 
A)  92.0 g 
B)  35.3 g 
C)  186 g 
D)  55.7 g

Question 13

According to the following thermochemical equation,what mass of HF (in g)must react in order to produce 345 kJ of energy? Assume excess SiO2.
SiO2(s)+ 4 HF(g)→ SiF4(g)+ 2 H2O(l)ΔH°rxn = -184 kJ

Accepted Answer

A)  42.7 g 
B)  37.5 g 
C)  150. g 
D)  107 g 
E)  173 g 
A)  42.7 g 
B)  37.5 g 
C)  150. g 
D)  107 g 
E)  173 g

Question 14

Energy that is associated with the relative positions of electrons and nuclei in atoms and molecules is called

Accepted Answer

A)  kinetic energy. 
B)  thermal energy. 
C)  gravitational energy. 
D)  chemical energy. 
A)  kinetic energy. 
B)  thermal energy. 
C)  gravitational energy. 
D)  chemical energy.

Question 15

Which of the following processes is endothermic?

Accepted Answer

A)  the freezing of water 
B)  the combustion of butane 
C)  a hot cup of coffee (system) cools on a countertop 
D)  the chemical reaction in a "hot pack" often used to treat sore muscles 
E)  the vaporization of rubbing alcohol 
A)  the freezing of water 
B)  the combustion of butane 
C)  a hot cup of coffee (system) cools on a countertop 
D)  the chemical reaction in a "hot pack" often used to treat sore muscles 
E)  the vaporization of rubbing alcohol

Question 16

Use the bond energies provided to estimate ΔH°rxn for the reaction below. CH3OH(l)+ 2 O2(g)→ CO2(g)+ 2 H2O(g)ΔH°rxn = ?
Bond Bond Energy (kJ/mol)
C-H 414
C-O 360
C=O 799
O=O 498
O-H 464

Accepted Answer

A)  +473 kJ 
B)  -91 kJ 
C)  -486 kJ 
D)  -392 kJ 
E)  +206 kJ 
A)  +473 kJ 
B)  -91 kJ 
C)  -486 kJ 
D)  -392 kJ 
E)  +206 kJ

Question 17

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction 2 NO(g)+ O2(g)→ 2 NO2(g)ΔH°rxn = ?
Given:
N2(g)+ O2(g)→ 2 NO(g)ΔH°rxn = +183 kJ
1/2 N2(g)+ O2(g)→ NO2(g)ΔH°rxn = +33 kJ

Accepted Answer

A)  -150. kJ 
B)  -117 kJ 
C)  -333 kJ 
D)  +115 kJ 
E)  +238 kJ 
A)  -150. kJ 
B)  -117 kJ 
C)  -333 kJ 
D)  +115 kJ 
E)  +238 kJ

Question 18

Use the ΔH°f and ΔH°rxn information provided to calculate ΔH°f for SO3(g) ΔH°f (kJ/mol) 2 SO2(g)+ O2(g)→ 2 SO3(g)ΔH°rxn = -198 kJ
SO2(g)-297

Accepted Answer

A)  -792 kJ/mol 
B)  -248 kJ/mol 
C)  -495 kJ/mol 
D)  -578 kJ/mol 
E)  -396 kJ/mol 
A)  -792 kJ/mol 
B)  -248 kJ/mol 
C)  -495 kJ/mol 
D)  -578 kJ/mol 
E)  -396 kJ/mol

Question 19

Determine the specific heat capacity of an alloy that requires 59.3 kJ to raise the temperature of 150.0 g alloy from 298 K to 398 K.

Accepted Answer

A)  4.38 J/g°C 
B)  2.29 J/g°C 
C)  3.95 J/g°C 
D)  2.53 J/g°C 
E)  1.87 J/g°C 
A)  4.38 J/g°C 
B)  2.29 J/g°C 
C)  3.95 J/g°C 
D)  2.53 J/g°C 
E)  1.87 J/g°C

Question 20

Use the ΔH°f and ΔH°rxn information provided to calculate ΔH°f for IF ΔH°f (kJ/mol) IF7(g)+ I2(g)→ IF5(g)+ 2 IF(g)ΔH°rxn = -89 kJ
IF7(g)941
IF5(g)840

Accepted Answer

A)  101 kJ/mol 
B)  -146 kJ/mol 
C)  -190. kJ/mol 
D)  -95 kJ/mol 
E)  24 kJ/mol 
A)  101 kJ/mol 
B)  -146 kJ/mol 
C)  -190. kJ/mol 
D)  -95 kJ/mol 
E)  24 kJ/mol

Exam 10: Thermochemistry

Which of the following statements is TRUE?

At 1 atm pressure,the heat of sublimation of gallium is 277.0kJ/mol and the heat of vaporization is 271.0 kJ/mol.To the correct number of significant figures,how much heat is required to melt 5.50 mol of gallium at 1 atm pressure?

It takes 18.2 kJ of energy to raise the temperature of 55.2g of an unknown liquid from 30.0°C to 47.0°C.What is the specific heat of the unknown liquid

Where does the energy absorbed during an endothermic reaction go?

Which of the following processes are endothermic?

When 10.00 moles of H2(g)reacts with 5.000 mol of O2(g)to form 10.00 mol of H2O(l)at 25°C and a constant pressure of 1.00 atm.If 683.0 kJ of heat are released during this reaction,and PΔV is equal to -37.00 kJ,then

Choose the reaction that illustrates ΔH°f for Mg(NO3)2.

What is the enthalpy change (in kJ)of a chemical reaction that raises the temperature of 250.0 mL of solution having a density of 1.25 g/ml by 7.80°C? (The specific heat of the solution is 3.74 J/g∙K.)

Give the units of heat capacity.

Which one of the following elements is NOT in its standard state?

If a block of gold requires 1.42 kJ of energy to raise the temperature from 120.0°C to 240.0°C,what is the mass of the block? The specific heat capacity of gold is 0.129 J/g-K.

According to the following thermochemical equation,what mass of HF (in g)must react in order to produce 345 kJ of energy? Assume excess SiO2. SiO2(s)+ 4 HF(g)→ SiF4(g)+ 2 H2O(l)ΔH°rxn = -184 kJ

Energy that is associated with the relative positions of electrons and nuclei in atoms and molecules is called

Which of the following processes is endothermic?

Use the bond energies provided to estimate ΔH°rxn for the reaction below. CH3OH(l)+ 2 O2(g)→ CO2(g)+ 2 H2O(g)ΔH°rxn = ? Bond Bond Energy (kJ/mol) C-H 414 C-O 360 C=O 799 O=O 498 O-H 464

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction 2 NO(g)+ O2(g)→ 2 NO2(g)ΔH°rxn = ? Given: N2(g)+ O2(g)→ 2 NO(g)ΔH°rxn = +183 kJ 1/2 N2(g)+ O2(g)→ NO2(g)ΔH°rxn = +33 kJ

Use the ΔH°f and ΔH°rxn information provided to calculate ΔH°f for SO3(g) ΔH°f (kJ/mol) 2 SO2(g)+ O2(g)→ 2 SO3(g)ΔH°rxn = -198 kJ SO2(g)-297

Determine the specific heat capacity of an alloy that requires 59.3 kJ to raise the temperature of 150.0 g alloy from 298 K to 398 K.

Use the ΔH°f and ΔH°rxn information provided to calculate ΔH°f for IF ΔH°f (kJ/mol) IF7(g)+ I2(g)→ IF5(g)+ 2 IF(g)ΔH°rxn = -89 kJ IF7(g)941 IF5(g)840

Essentials: Units, Measurements, and Problem Solving

Atoms

The Quantum Mechanical Model of the Atom

Periodic Properties of the Elements

Molecules and Compounds

Chemical Bonding I

Chemical Bonding Ii

Chemical Reactions and Chemical Quantities

Introduction to Solutions and Aqueous Reactions

Gases

Liquids, Solids, and Intermolecular Forces

Crystalline Solids and Modern Materials

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Free Energy and Thermodynamics

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry

Transition Metals and Coordination Compounds

Filters

When 10.00 moles of H₂(g)reacts with 5.000 mol of O₂(g)to form 10.00 mol of H₂O(l)at 25°C and a constant pressure of 1.00 atm.If 683.0 kJ of heat are released during this reaction,and PΔV is equal to -37.00 kJ,then

Choose the reaction that illustrates ΔH°_f for Mg(NO₃)₂.

According to the following thermochemical equation,what mass of HF (in g)must react in order to produce 345 kJ of energy? Assume excess SiO₂. SiO₂(s)+ 4 HF(g)→ SiF₄(g)+ 2 H₂O(l)ΔH°_rxn= -184 kJ

Use the bond energies provided to estimate ΔH°_rxn for the reaction below. CH₃OH(l)+ 2 O₂(g)→ CO₂(g)+ 2 H₂O(g)ΔH°_rxn= ? Bond Bond Energy (kJ/mol) C-H 414 C-O 360 C=O 799 O=O 498 O-H 464

Use the standard reaction enthalpies given below to determine ΔH°_rxn for the following reaction 2 NO(g)+ O₂(g)→ 2 NO₂(g)ΔH°_rxn= ? Given: N₂(g)+ O₂(g)→ 2 NO(g)ΔH°_rxn= +183 kJ 1/2 N₂(g)+ O₂(g)→ NO₂(g)ΔH°_rxn= +33 kJ

Use the ΔH°_f and ΔH°_rxninformation provided to calculate ΔH°_f for SO₃(g) ΔH°_{f (kJ/mol)} 2 SO₂(g)+ O₂(g)→ 2 SO₃(g)ΔH°_rxn= -198 kJ SO₂(g)-297

Use the ΔH°_f and ΔH°_rxn information provided to calculate ΔH°_f for IF ΔH°_{f (kJ/mol)} IF₇(g)+ I₂(g)→ IF₅(g)+ 2 IF(g)ΔH°_rxn= -89 kJ IF₇(g)941 IF₅(g)840