CHEM 103 Module 4 | General Chemistry I with Lab Exam Q&A | Portage
Learning
Here are 100 original practice questions for CHEM 103 Module 4 |
Thermochemistry, Gases, and Thermodynamics. These are original review
items, not official exam questions.
Question 1:
Which statement best defines energy?
A. Anything that has mass and volume
B. The capacity to do work or transfer heat
C. A measure of particle size
D. A type of chemical bond
Correct answer: B
Rationale:
Energy is the capacity to do work or transfer heat. It exists in many forms,
including kinetic, potential, thermal, chemical, and electrical.
Question 2:
A reaction releases heat to its surroundings. This reaction is:
A. Endothermic
B. Exothermic
C. Isothermal
D. Adiabatic
Correct answer: B
Rationale:
Exothermic reactions release heat, causing the surroundings to warm.
Question 3:
A reaction absorbs heat from its surroundings. This reaction is:
,A. Exothermic
B. Endothermic
C. Combustion
D. Neutralization
Correct answer: B
Rationale:
Endothermic reactions absorb heat, causing the surroundings to cool.
Question 4:
What is the SI unit of energy?
A. Calorie
B. Joule
C. Kelvin
D. Liter
Correct answer: B
Rationale:
The SI unit of energy is the joule (J). The calorie is also used, but it is not the SI
unit.
Question 5:
The first law of thermodynamics states that:
A. Energy can be created
B. Energy can be destroyed
C. Energy is conserved
D. Entropy always increases
Correct answer: C
Rationale:
The first law is the law of conservation of energy: energy cannot be created or
destroyed, only converted.
,Question 6:
In thermochemistry, the system is:
A. The part of the universe being studied
B. Everything outside the reaction
C. Always the universe
D. Only the solvent
Correct answer: A
Rationale:
The system is the specific part of the universe under study. The surroundings
are everything else.
Question 7:
Which quantity is a state function?
A. Heat
B. Work
C. Enthalpy
D. Distance
Correct answer: C
Rationale:
Enthalpy is a state function; it depends only on the current state, not the path.
Heat and work are path-dependent.
Question 8:
Enthalpy change (ΔH) equals heat change when pressure is:
A. Constant
B. Zero
C. Increasing
D. Variable
Correct answer: A
Rationale:
, At constant pressure, ΔH equals the heat absorbed or released by the system.
Question 9:
A negative ΔH indicates a(n):
A. Endothermic reaction
B. Exothermic reaction
C. Spontaneous reaction always
D. Nonspontaneous reaction always
Correct answer: B
Rationale:
A negative ΔH means the system loses heat to the surroundings, so the reaction
is exothermic.
Question 10:
A positive ΔH indicates a(n):
A. Exothermic reaction
B. Endothermic reaction
C. Always spontaneous reaction
D. Always nonspontaneous reaction
Correct answer: B
Rationale:
A positive ΔH means the system absorbs heat, so the reaction is endothermic.
Question 11:
Specific heat is the amount of heat required to raise the temperature of:
A. 1 g of a substance by 1°C
B. 1 mole of a substance by 1°C
C. 1 L of a substance by 1°C
D. 1 kg of a substance by 10°C
Learning
Here are 100 original practice questions for CHEM 103 Module 4 |
Thermochemistry, Gases, and Thermodynamics. These are original review
items, not official exam questions.
Question 1:
Which statement best defines energy?
A. Anything that has mass and volume
B. The capacity to do work or transfer heat
C. A measure of particle size
D. A type of chemical bond
Correct answer: B
Rationale:
Energy is the capacity to do work or transfer heat. It exists in many forms,
including kinetic, potential, thermal, chemical, and electrical.
Question 2:
A reaction releases heat to its surroundings. This reaction is:
A. Endothermic
B. Exothermic
C. Isothermal
D. Adiabatic
Correct answer: B
Rationale:
Exothermic reactions release heat, causing the surroundings to warm.
Question 3:
A reaction absorbs heat from its surroundings. This reaction is:
,A. Exothermic
B. Endothermic
C. Combustion
D. Neutralization
Correct answer: B
Rationale:
Endothermic reactions absorb heat, causing the surroundings to cool.
Question 4:
What is the SI unit of energy?
A. Calorie
B. Joule
C. Kelvin
D. Liter
Correct answer: B
Rationale:
The SI unit of energy is the joule (J). The calorie is also used, but it is not the SI
unit.
Question 5:
The first law of thermodynamics states that:
A. Energy can be created
B. Energy can be destroyed
C. Energy is conserved
D. Entropy always increases
Correct answer: C
Rationale:
The first law is the law of conservation of energy: energy cannot be created or
destroyed, only converted.
,Question 6:
In thermochemistry, the system is:
A. The part of the universe being studied
B. Everything outside the reaction
C. Always the universe
D. Only the solvent
Correct answer: A
Rationale:
The system is the specific part of the universe under study. The surroundings
are everything else.
Question 7:
Which quantity is a state function?
A. Heat
B. Work
C. Enthalpy
D. Distance
Correct answer: C
Rationale:
Enthalpy is a state function; it depends only on the current state, not the path.
Heat and work are path-dependent.
Question 8:
Enthalpy change (ΔH) equals heat change when pressure is:
A. Constant
B. Zero
C. Increasing
D. Variable
Correct answer: A
Rationale:
, At constant pressure, ΔH equals the heat absorbed or released by the system.
Question 9:
A negative ΔH indicates a(n):
A. Endothermic reaction
B. Exothermic reaction
C. Spontaneous reaction always
D. Nonspontaneous reaction always
Correct answer: B
Rationale:
A negative ΔH means the system loses heat to the surroundings, so the reaction
is exothermic.
Question 10:
A positive ΔH indicates a(n):
A. Exothermic reaction
B. Endothermic reaction
C. Always spontaneous reaction
D. Always nonspontaneous reaction
Correct answer: B
Rationale:
A positive ΔH means the system absorbs heat, so the reaction is endothermic.
Question 11:
Specific heat is the amount of heat required to raise the temperature of:
A. 1 g of a substance by 1°C
B. 1 mole of a substance by 1°C
C. 1 L of a substance by 1°C
D. 1 kg of a substance by 10°C
