Question 1

The term standard conditions with respect to enthalpy change means ________.

Accepted Answer

A) 1 atm and 0 K 
B) 1 atm and 1 L 
C) 1 atm and 298 K 
D) 1 L and 0 K 
E) 1 atm and 1 °C 
A) 1 atm and 0 K 
B) 1 atm and 1 L 
C) 1 atm and 298 K 
D) 1 L and 0 K 
E) 1 atm and 1 °C

Question 2

Which one of the following statements is true?

Accepted Answer

A) Enthalpy is an intensive property. 
B) The enthalpy change for a reaction is independent of the state of the reactants and products. 
C) Enthalpy is a state function. 
D) H is the value of q measured under conditions of constant volume. 
E) The enthalpy change of a reaction is the reciprocal of the ΔH of the reverse reaction. 
A) Enthalpy is an intensive property. 
B) The enthalpy change for a reaction is independent of the state of the reactants and products. 
C) Enthalpy is a state function. 
D) H is the value of q measured under conditions of constant volume. 
E) The enthalpy change of a reaction is the reciprocal of the ΔH of the reverse reaction.

Question 3

The value of ΔE for a system that performs 139 kJ of work on its surroundings and gains   of heat is

Accepted Answer

A) -85 
B) 193 
C) 7506 
D) 85 
E) -193 
A) -85 
B) 193 
C) 7506 
D) 85 
E) -193

Question 4

A 23.2 g piece of space debris is traveling at 81.9 m/s.What is the kinetic energy of the space debris?

Accepted Answer

A) 145 J 
B) 1450 J 
C) 0.950 J 
D) 77800 J 
E) 77.8 J 
A) 145 J 
B) 1450 J 
C) 0.950 J 
D) 77800 J 
E) 77.8 J

Question 5

Given the following reactions N2 (g)+ O2 (g)→ 2NO (g)ΔH = +180.7 kJ
2N2O (g)→ O2 (g)+ 2N2 (g)ΔH = -163.2 kJ
The enthalpy of reaction for
2N2O (g)→ 2NO (g)+ N2 (g)
Is ________ kJ.

Accepted Answer

A) 145.7 
B) 343.9 
C) -343.9 
D) 17.5 
E) -145.7 
A) 145.7 
B) 343.9 
C) -343.9 
D) 17.5 
E) -145.7

Question 6

A chemical reaction that absorbs heat from the surroundings is said to be ________ and has a ________ ΔH at constant pressure.

Accepted Answer

A) endothermic, positive 
B) endothermic, negative 
C) exothermic, negative 
D) exothermic, positive 
E) exothermic, neutral 
A) endothermic, positive 
B) endothermic, negative 
C) exothermic, negative 
D) exothermic, positive 
E) exothermic, neutral

Question 7

The energy released by combustion of ________ of a substance is called the fuel value of the substance.

Accepted Answer

A) 1 kJ 
B) 1 kg 
C) 1 lb 
D) 1 J 
E) 1 g 
A) 1 kJ 
B) 1 kg 
C) 1 lb 
D) 1 J 
E) 1 g

Question 8

Calculate the kinetic energy in joules of an automobile weighing 4345 lb and traveling at 75 mph.

Accepted Answer

A) 5.5 × 105 J 
B) 5.5 × 10-5 J 
C) 1.1 × 106 J 
D) 2.2 × 106 J 
E) 2.2 × 10-6 J 
A) 5.5 × 105 J 
B) 5.5 × 10-5 J 
C) 1.1 × 106 J 
D) 2.2 × 106 J 
E) 2.2 × 10-6 J

Question 9

Given the data in the table below,ΔH°rxn for the reaction 3NO2 (g)+ H2O (l)→ 2HNO3 (aq)+ NO (g)
Is ________ kJ.

Accepted Answer

A) 64 
B) 140 
C) -140 
D) -508 
E) -64 
A) 64 
B) 140 
C) -140 
D) -508 
E) -64

Question 10

In the reaction below,ΔH°f is zero for ________. Ni (s)+ 2CO (g)+ 2PF3 (g)→ Ni(CO)2(PF3)2 (l)

Accepted Answer

A) Ni (s) 
B) CO (g) 
C) PF3 (g) 
D) Ni(CO)2(PF3)2 (l) 
E) both CO (g)and PF3 (g) 
A) Ni (s) 
B) CO (g) 
C) PF3 (g) 
D) Ni(CO)2(PF3)2 (l) 
E) both CO (g)and PF3 (g)

Question 11

For a given process at constant pressure,w is positive.This means that the process involves ________.

Accepted Answer

A) work being done by the system on the surroundings 
B) work being done by the surroundings on the system 
C) no work being done 
D) an equal amount of work done on the system and by the system 
E) work being done against a vacuum 
A) work being done by the system on the surroundings 
B) work being done by the surroundings on the system 
C) no work being done 
D) an equal amount of work done on the system and by the system 
E) work being done against a vacuum

Question 12

The specific heat capacity of liquid mercury is 0.14 J/g-K.How many joules of heat are needed to raise the temperature of 6.00 g of mercury from 25.1 °C to 65.3 °C?

Accepted Answer

A) 1.7 × 103 J 
B) 34 J 
C) 76 J 
D) 5.8 × 10-4 J 
E) 2.2 J 
A) 1.7 × 103 J 
B) 34 J 
C) 76 J 
D) 5.8 × 10-4 J 
E) 2.2 J

Question 13

How much heat is released when 29.5 grams of Cl2 (g)reacts with excess hydrogen?
H2 (g)+ Cl2 (g)→ 2HCl (g)ΔH° = -186 kJ.

Accepted Answer

A) 186 kJ 
B) 310 kJ 
C) -77.4 kJ 
D) -186 kJ 
E) 77.4 kJ 
A) 186 kJ 
B) 310 kJ 
C) -77.4 kJ 
D) -186 kJ 
E) 77.4 kJ

Question 14

When 0.800 grams of NaOH is dissolved in 100.0 grams of water,the temperature of the solution increases from 25.00 °C to 27.06 °C.The amount of heat absorbed by the water is ________ J.(The specific heat of water is 4.18 J/g-°C.)

Accepted Answer

The answer of When 0.800 grams of NaOH is dissolved...

Question 15

The value of ΔH° for the reaction below is -126 kJ.The amount of heat that is released by the reaction of 10.0 g of Na2O2 with water is ________ kJ. 2Na2O2 (s)+ 2H2O (l)→ 4NaOH (s)+ O2 (g)

Accepted Answer

A) 8.08 
B) 16.2 
C) 67.5 
D) 32.3 
E) -126 
A) 8.08 
B) 16.2 
C) 67.5 
D) 32.3 
E) -126

Question 16

Given the data in the table below,ΔH°rxn for the reaction PCl3 (g)+ 3HCl (g)→ 3Cl2 (g)+ PH3 (g)
Is ________ kJ.

Accepted Answer

A) -570.37 
B) -385.77 
C) 570.37 
D) 385.77 
E) The ΔH°f of Cl2 (g)is needed for the calculation. 
A) -570.37 
B) -385.77 
C) 570.37 
D) 385.77 
E) The ΔH°f of Cl2 (g)is needed for the calculation.

Question 17

Given the following reactions Fe2O3 (s)+ 3CO (s)→ 2Fe (s)+ 3CO2 (g)ΔH = -28.0 kJ
3Fe (s)+ 4CO2(s)→ 4CO (g)+ Fe3O4(s)ΔH = +12.5 kJ
The enthalpy of the reaction of Fe2O3 with CO
3Fe2O3 (s)+ CO (g)→ CO2 (g)+ 2Fe3O4 (s)
Is ________ kJ.

Accepted Answer

A) -59.0 
B) 40.5 
C) -15.5 
D) -109 
E) +109 
A) -59.0 
B) 40.5 
C) -15.5 
D) -109 
E) +109

Question 18

Which one of the following is an endothermic process?

Accepted Answer

A) ice melting 
B) water freezing 
C) boiling soup 
D) Hydrochloric acid and barium hydroxide are mixed at 25 °C: the temperature increases. 
E) Both A and C 
A) ice melting 
B) water freezing 
C) boiling soup 
D) Hydrochloric acid and barium hydroxide are mixed at 25 °C: the temperature increases. 
E) Both A and C

Question 19

ΔH for an endothermic process is ________ while ΔH for an exothermic process is ________.

Accepted Answer

A) zero, positive 
B) zero, negative 
C) positive, zero 
D) negative, positive 
E) positive, negative 
A) zero, positive 
B) zero, negative 
C) positive, zero 
D) negative, positive 
E) positive, negative

Question 20

The value of ΔH° for the reaction below is -126 kJ. ________ kj are released when 2.00 mol of NaOH is formed in the reaction?
2Na2O2 (s)+ 2H2O (l)→ 4NaOH (s)+ O2 (g)

Accepted Answer

A) 252 
B) 63 
C) 3.9 
D) 7.8 
E) -126 
A) 252 
B) 63 
C) 3.9 
D) 7.8 
E) -126

Exam 5: Thermochemistry

The term standard conditions with respect to enthalpy change means ________.

Which one of the following statements is true?

The value of ΔE for a system that performs 139 kJ of work on its surroundings and gains of heat is

A 23.2 g piece of space debris is traveling at 81.9 m/s.What is the kinetic energy of the space debris?

Given the following reactions N2 (g)+ O2 (g)→ 2NO (g)ΔH = +180.7 kJ 2N2O (g)→ O2 (g)+ 2N2 (g)ΔH = -163.2 kJ The enthalpy of reaction for 2N2O (g)→ 2NO (g)+ N2 (g) Is ________ kJ.

A chemical reaction that absorbs heat from the surroundings is said to be ________ and has a ________ ΔH at constant pressure.

The energy released by combustion of ________ of a substance is called the fuel value of the substance.

Calculate the kinetic energy in joules of an automobile weighing 4345 lb and traveling at 75 mph.

Given the data in the table below,ΔH°rxn for the reaction 3NO2 (g)+ H2O (l)→ 2HNO3 (aq)+ NO (g) Is ________ kJ.

In the reaction below,ΔH°f is zero for ________. Ni (s)+ 2CO (g)+ 2PF3 (g)→ Ni(CO)2(PF3)2 (l)

For a given process at constant pressure,w is positive.This means that the process involves ________.

The specific heat capacity of liquid mercury is 0.14 J/g-K.How many joules of heat are needed to raise the temperature of 6.00 g of mercury from 25.1 °C to 65.3 °C?

How much heat is released when 29.5 grams of Cl2 (g)reacts with excess hydrogen? H2 (g)+ Cl2 (g)→ 2HCl (g)ΔH° = -186 kJ.

When 0.800 grams of NaOH is dissolved in 100.0 grams of water,the temperature of the solution increases from 25.00 °C to 27.06 °C.The amount of heat absorbed by the water is ________ J.(The specific heat of water is 4.18 J/g-°C.)

The value of ΔH° for the reaction below is -126 kJ.The amount of heat that is released by the reaction of 10.0 g of Na2O2 with water is ________ kJ. 2Na2O2 (s)+ 2H2O (l)→ 4NaOH (s)+ O2 (g)

Given the data in the table below,ΔH°rxn for the reaction PCl3 (g)+ 3HCl (g)→ 3Cl2 (g)+ PH3 (g) Is ________ kJ.

Given the following reactions Fe2O3 (s)+ 3CO (s)→ 2Fe (s)+ 3CO2 (g)ΔH = -28.0 kJ 3Fe (s)+ 4CO2(s)→ 4CO (g)+ Fe3O4(s)ΔH = +12.5 kJ The enthalpy of the reaction of Fe2O3 with CO 3Fe2O3 (s)+ CO (g)→ CO2 (g)+ 2Fe3O4 (s) Is ________ kJ.

Which one of the following is an endothermic process?

ΔH for an endothermic process is ________ while ΔH for an exothermic process is ________.

The value of ΔH° for the reaction below is -126 kJ. ________ kj are released when 2.00 mol of NaOH is formed in the reaction? 2Na2O2 (s)+ 2H2O (l)→ 4NaOH (s)+ O2 (g)

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Chemical Reactions and Reaction Stoichiometry

Reactions in Aqueous Solution

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

Given the following reactions N₂ (g)+ O₂ (g)→ 2NO (g)ΔH = +180.7 kJ 2N₂O (g)→ O₂ (g)+ 2N₂ (g)ΔH = -163.2 kJ The enthalpy of reaction for 2N₂O (g)→ 2NO (g)+ N₂ (g) Is ________ kJ.

A chemical reaction that absorbs heat from the surroundings is said to be and has a ΔH at constant pressure.

Given the data in the table below,ΔH°_rxn for the reaction 3NO₂ (g)+ H₂O (l)→ 2HNO₃ (aq)+ NO (g) Is ________ kJ.

In the reaction below,ΔH°_f is zero for ________. Ni (s)+ 2CO (g)+ 2PF₃ (g)→ Ni(CO)₂(PF₃)₂ (l)

How much heat is released when 29.5 grams of Cl₂ (g)reacts with excess hydrogen? H₂ (g)+ Cl₂ (g)→ 2HCl (g)ΔH° = -186 kJ.

The value of ΔH° for the reaction below is -126 kJ.The amount of heat that is released by the reaction of 10.0 g of Na₂O₂ with water is ________ kJ. 2Na₂O₂ (s)+ 2H₂O (l)→ 4NaOH (s)+ O₂ (g)

Given the data in the table below,ΔH°_rxn for the reaction PCl₃ (g)+ 3HCl (g)→ 3Cl₂ (g)+ PH₃ (g) Is ________ kJ.

Given the following reactions Fe₂O₃ (s)+ 3CO (s)→ 2Fe (s)+ 3CO₂ (g)ΔH = -28.0 kJ 3Fe (s)+ 4CO₂(s)→ 4CO (g)+ Fe₃O₄(s)ΔH = +12.5 kJ The enthalpy of the reaction of Fe₂O₃ with CO 3Fe₂O₃ (s)+ CO (g)→ CO₂ (g)+ 2Fe₃O₄ (s) Is ________ kJ.

ΔH for an endothermic process is while ΔH for an exothermic process is .

The value of ΔH° for the reaction below is -126 kJ. ________ kj are released when 2.00 mol of NaOH is formed in the reaction? 2Na₂O₂ (s)+ 2H₂O (l)→ 4NaOH (s)+ O₂ (g)