CHM 101 EXAM 1 DONOVAN] – QUESTIONS AND ANSWERS | VERIFIED AND WELL DETAILED
ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
1. Atomic Structure and Periodic Trends
2. Chemical Bonding and Molecular Geometry
3. Stoichiometry and Chemical Reactions
4. Thermochemistry and Thermodynamics
5. Gases, Liquids, and Solids
6. Solutions and Colligative Properties
7. Kinetics and Equilibrium
8. Acids, Bases, and pH
9. Organic Chemistry Fundamentals
10. Laboratory Safety and Instrumentation
Introduction
This comprehensive examination is designed to assess your foundational understanding and practical
application of core chemistry principles as outlined in CHM 101. The assessment covers a wide range of
topics, from atomic theory and chemical bonding to thermodynamics and acid-base chemistry. You will
be presented with multiple-choice questions and scenario-based problems that test not only your recall of
key concepts but also your ability to apply knowledge in a decision-making context. This exam
emphasizes real-world applications, requiring critical thinking to solve complex problems and interpret
data. Success on this exam demonstrates a solid command of the subject matter and a readiness for
advanced study.
SECTION ONE: QUESTIONS 1–100
1. Which subatomic particle has a relative mass of approximately 1 atomic mass unit and a charge of
+1?
A. Electron
B. Neutron
C. Proton
D. Positron
🟢 C. Proton
🔴 Explanation: The proton is the subatomic particle with a mass of about 1 amu and a charge of +1.
Electrons have a negligible mass and a -1 charge, while neutrons have a mass of about 1 amu but are
neutral.
2. The element with the electron configuration [Ne] 3s² 3p⁵ belongs to which group and period?
A. Group 17, Period 2
B. Group 17, Period 3
C. Group 15, Period 3
D. Group 2, Period 3
🟢 B. Group 17, Period 3
🔴 Explanation: The configuration [Ne] 3s² 3p⁵ has its highest principal quantum number as 3 (Period
,3), and its p-orbital has 5 electrons (needs one more for a full octet), characteristic of Group 17
(halogens).
3. Which of the following compounds is expected to have the highest lattice energy?
A. NaCl
B. MgO
C. CaCl₂
D. KBr
🟢 B. MgO
🔴 Explanation: Lattice energy is directly proportional to the product of ionic charges and inversely
proportional to the distance between ions. MgO consists of Mg²⁺ and O²⁻, which have the highest
charge product (+2 x -2 = -4) compared to the other options, leading to the strongest electrostatic
attraction.
4. In the reaction 2H₂ + O₂ → 2H₂O, what is the limiting reactant if 5.0 mol of H₂ reacts with 3.0 mol
of O₂?
A. H₂
B. O₂
C. Both are limiting
D. H₂O
🟢 A. H₂
🔴 Explanation: From the stoichiometry, 2 mol of H₂ react with 1 mol of O₂. To react with 3.0 mol of
O₂, 6.0 mol of H₂ would be needed. Since only 5.0 mol of H₂ are available, H₂ is the limiting reactant.
5. A sample of nitrogen gas occupies a volume of 10.0 L at a pressure of 2.0 atm. If the temperature
is held constant, what is the final volume when the pressure is decreased to 1.0 atm?
A. 5.0 L
B. 10.0 L
C. 15.0 L
D. 20.0 L
🟢 D. 20.0 L
🔴 Explanation: According to Boyle's Law (P₁V₁ = P₂V₂), the volume is inversely proportional to
pressure. V₂ = (P₁V₁)/P₂ = (2.0 atm * 10.0 L) / 1.0 atm = 20.0 L.
6. A chemist is analyzing an unknown organic compound and observes a strong absorption band at
1715 cm⁻¹ in its IR spectrum. This absorption is most characteristic of which functional group?
A. Alcohol (O-H)
B. Carbonyl (C=O)
C. Alkene (C=C)
D. Amine (N-H)
🟢 B. Carbonyl (C=O)
🔴 Explanation: A strong absorption band in the 1680-1750 cm⁻¹ range is a classic signature of a
carbonyl (C=O) group. Alcohols show broad O-H stretches, alkenes have weaker C=C stretches, and
amines show N-H stretches in different regions.
7. Which of the following is a state function?
A. Heat
, B. Work
C. Enthalpy
D. Pathway
🟢 C. Enthalpy
🔴 Explanation: A state function's value depends only on the current state of the system, not on the
path taken to get there. Enthalpy (H), internal energy (U), and entropy (S) are all state functions. Heat
and work are path functions.
8. According to Le Chatelier's principle, increasing the temperature of an exothermic reaction will
cause the equilibrium to:
A. Shift to the right
B. Shift to the left
C. Have no effect
D. Increase the rate of the forward reaction only
🟢 B. Shift to the left
🔴 Explanation: In an exothermic reaction, heat is a product. Adding more heat (increasing
temperature) will shift the equilibrium to the left, favoring the reactants to consume the excess heat.
9. What is the pH of a 0.01 M solution of a strong acid like HCl?
A. 2
B. 1
C. 12
D. 7
🟢 A. 2
🔴 Explanation: A strong acid like HCl completely dissociates, so [H⁺] = 0.01 M. pH = -log₁₀[H⁺] = -
log₁₀(0.01) = -log₁₀(10⁻²) = 2.
10. A professional standards organization issues a new guideline for the disposal of chemical waste.
What is the primary purpose of such a guideline?
A. To increase laboratory costs
B. To protect human health and the environment
C. To make waste disposal more difficult
D. To satisfy a single laboratory's policy
🟢 B. To protect human health and the environment
🔴 Explanation: Professional guidelines and regulations for chemical waste disposal are established to
minimize the risks associated with hazardous materials, thereby safeguarding both human health and
the environment.
11. Which of the following represents an isotope of Uranium-238?
A. ²³⁸₉₃Np
B. ²³⁵₉₂U
C. ²³⁸₉₁Pa
D. ²³⁹₉₂U
🟢 B. ²³⁵₉₂U
🔴 Explanation: Isotopes are atoms of the same element that have the same number of protons
(atomic number, Z=92) but a different number of neutrons (mass number, A). ²³⁵₉₂U has the same Z of
92 but a different A (235) than U-238.
ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
1. Atomic Structure and Periodic Trends
2. Chemical Bonding and Molecular Geometry
3. Stoichiometry and Chemical Reactions
4. Thermochemistry and Thermodynamics
5. Gases, Liquids, and Solids
6. Solutions and Colligative Properties
7. Kinetics and Equilibrium
8. Acids, Bases, and pH
9. Organic Chemistry Fundamentals
10. Laboratory Safety and Instrumentation
Introduction
This comprehensive examination is designed to assess your foundational understanding and practical
application of core chemistry principles as outlined in CHM 101. The assessment covers a wide range of
topics, from atomic theory and chemical bonding to thermodynamics and acid-base chemistry. You will
be presented with multiple-choice questions and scenario-based problems that test not only your recall of
key concepts but also your ability to apply knowledge in a decision-making context. This exam
emphasizes real-world applications, requiring critical thinking to solve complex problems and interpret
data. Success on this exam demonstrates a solid command of the subject matter and a readiness for
advanced study.
SECTION ONE: QUESTIONS 1–100
1. Which subatomic particle has a relative mass of approximately 1 atomic mass unit and a charge of
+1?
A. Electron
B. Neutron
C. Proton
D. Positron
🟢 C. Proton
🔴 Explanation: The proton is the subatomic particle with a mass of about 1 amu and a charge of +1.
Electrons have a negligible mass and a -1 charge, while neutrons have a mass of about 1 amu but are
neutral.
2. The element with the electron configuration [Ne] 3s² 3p⁵ belongs to which group and period?
A. Group 17, Period 2
B. Group 17, Period 3
C. Group 15, Period 3
D. Group 2, Period 3
🟢 B. Group 17, Period 3
🔴 Explanation: The configuration [Ne] 3s² 3p⁵ has its highest principal quantum number as 3 (Period
,3), and its p-orbital has 5 electrons (needs one more for a full octet), characteristic of Group 17
(halogens).
3. Which of the following compounds is expected to have the highest lattice energy?
A. NaCl
B. MgO
C. CaCl₂
D. KBr
🟢 B. MgO
🔴 Explanation: Lattice energy is directly proportional to the product of ionic charges and inversely
proportional to the distance between ions. MgO consists of Mg²⁺ and O²⁻, which have the highest
charge product (+2 x -2 = -4) compared to the other options, leading to the strongest electrostatic
attraction.
4. In the reaction 2H₂ + O₂ → 2H₂O, what is the limiting reactant if 5.0 mol of H₂ reacts with 3.0 mol
of O₂?
A. H₂
B. O₂
C. Both are limiting
D. H₂O
🟢 A. H₂
🔴 Explanation: From the stoichiometry, 2 mol of H₂ react with 1 mol of O₂. To react with 3.0 mol of
O₂, 6.0 mol of H₂ would be needed. Since only 5.0 mol of H₂ are available, H₂ is the limiting reactant.
5. A sample of nitrogen gas occupies a volume of 10.0 L at a pressure of 2.0 atm. If the temperature
is held constant, what is the final volume when the pressure is decreased to 1.0 atm?
A. 5.0 L
B. 10.0 L
C. 15.0 L
D. 20.0 L
🟢 D. 20.0 L
🔴 Explanation: According to Boyle's Law (P₁V₁ = P₂V₂), the volume is inversely proportional to
pressure. V₂ = (P₁V₁)/P₂ = (2.0 atm * 10.0 L) / 1.0 atm = 20.0 L.
6. A chemist is analyzing an unknown organic compound and observes a strong absorption band at
1715 cm⁻¹ in its IR spectrum. This absorption is most characteristic of which functional group?
A. Alcohol (O-H)
B. Carbonyl (C=O)
C. Alkene (C=C)
D. Amine (N-H)
🟢 B. Carbonyl (C=O)
🔴 Explanation: A strong absorption band in the 1680-1750 cm⁻¹ range is a classic signature of a
carbonyl (C=O) group. Alcohols show broad O-H stretches, alkenes have weaker C=C stretches, and
amines show N-H stretches in different regions.
7. Which of the following is a state function?
A. Heat
, B. Work
C. Enthalpy
D. Pathway
🟢 C. Enthalpy
🔴 Explanation: A state function's value depends only on the current state of the system, not on the
path taken to get there. Enthalpy (H), internal energy (U), and entropy (S) are all state functions. Heat
and work are path functions.
8. According to Le Chatelier's principle, increasing the temperature of an exothermic reaction will
cause the equilibrium to:
A. Shift to the right
B. Shift to the left
C. Have no effect
D. Increase the rate of the forward reaction only
🟢 B. Shift to the left
🔴 Explanation: In an exothermic reaction, heat is a product. Adding more heat (increasing
temperature) will shift the equilibrium to the left, favoring the reactants to consume the excess heat.
9. What is the pH of a 0.01 M solution of a strong acid like HCl?
A. 2
B. 1
C. 12
D. 7
🟢 A. 2
🔴 Explanation: A strong acid like HCl completely dissociates, so [H⁺] = 0.01 M. pH = -log₁₀[H⁺] = -
log₁₀(0.01) = -log₁₀(10⁻²) = 2.
10. A professional standards organization issues a new guideline for the disposal of chemical waste.
What is the primary purpose of such a guideline?
A. To increase laboratory costs
B. To protect human health and the environment
C. To make waste disposal more difficult
D. To satisfy a single laboratory's policy
🟢 B. To protect human health and the environment
🔴 Explanation: Professional guidelines and regulations for chemical waste disposal are established to
minimize the risks associated with hazardous materials, thereby safeguarding both human health and
the environment.
11. Which of the following represents an isotope of Uranium-238?
A. ²³⁸₉₃Np
B. ²³⁵₉₂U
C. ²³⁸₉₁Pa
D. ²³⁹₉₂U
🟢 B. ²³⁵₉₂U
🔴 Explanation: Isotopes are atoms of the same element that have the same number of protons
(atomic number, Z=92) but a different number of neutrons (mass number, A). ²³⁵₉₂U has the same Z of
92 but a different A (235) than U-238.
