Chem 210 Biochemistry Module 2 Actual Exam 2026/2027 |
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CHEM 210 BIOCHEMISTRY
MODULE 2 — ORIGINAL PRACTICE EXAMINATION
Aqueous Reactions, Water, Acids, Bases, pH & Buffers
Academic Year 2026/2027
Institution: Portage Learning
Course Code: CHEM 210
Course: Biochemistry
Module: 2
Document Type: 200-Question Original Practice Examination with Answers & Detailed
Rationales
Academic Year: 2026/2027
TABLE OF CONTENTS
Section Questions
Introduction 1–30
Core Concepts 31–90
Applied Scenarios 91–140
Critical Thinking 141–175
Review Questions 176–200
Total Questions: 200
SECTION I — INTRODUCTION
Questions 1–30
Question 1
Which property of water is primarily responsible for its ability to dissolve many ionic and polar
substances?
,A. Low density
B. Polarity
C. Nonpolar covalent bonding
D. High molecular mass
Correct Answer: B. Polarity
Rationale: Water has an uneven distribution of electron density because oxygen is more
electronegative than hydrogen. This polarity allows water molecules to interact favorably with
ions and other polar molecules.
Question 2
What type of bond holds the hydrogen and oxygen atoms together within a water molecule?
A. Hydrogen bond
B. Ionic bond
C. Polar covalent bond
D. Metallic bond
Correct Answer: C. Polar covalent bond
Rationale: Oxygen and hydrogen share electrons, so the bond is covalent. Because oxygen
attracts the shared electrons more strongly, the O–H bond is polar.
Question 3
What intermolecular interaction occurs between the partially positive hydrogen of one water
molecule and the partially negative oxygen of another?
A. Ionic bond
B. Hydrogen bond
C. Peptide bond
D. Metallic bond
Correct Answer: B. Hydrogen bond
Rationale: Hydrogen bonding occurs when hydrogen covalently attached to an electronegative
atom interacts with an electronegative atom in another molecule. Water forms extensive
hydrogen-bond networks.
Question 4
,Which atom carries a partial negative charge in a water molecule?
A. Hydrogen
B. Oxygen
C. Both atoms equally
D. Neither atom
Correct Answer: B. Oxygen
Rationale: Oxygen has a greater electronegativity than hydrogen and attracts the shared bonding
electrons more strongly. Oxygen therefore has a partial negative charge, while hydrogen atoms
have partial positive charges.
Question 5
Why is water considered a polar molecule?
A. It contains only hydrogen atoms
B. It has ionic bonds
C. Its bent geometry and polar O–H bonds produce a net dipole
D. It has no electronegativity differences
Correct Answer: C. Its bent geometry and polar O–H bonds produce a net dipole
Rationale: Each O–H bond is polar, and the bent molecular geometry prevents the bond dipoles
from canceling. Consequently, water has a net molecular dipole.
Question 6
Which property of water helps organisms resist rapid temperature changes?
A. High specific heat
B. Low polarity
C. Low boiling point
D. Poor hydrogen bonding
Correct Answer: A. High specific heat
Rationale: Hydrogen bonding allows water to absorb substantial thermal energy before its
temperature rises significantly. This contributes to temperature stability in biological systems.
Question 7
, A substance that interacts favorably with water is generally described as:
A. Hydrophilic
B. Hydrophobic
C. Nonpolar
D. Amphoteric only
Correct Answer: A. Hydrophilic
Rationale: Hydrophilic substances have ionic or polar regions that interact favorably with water.
Many salts and polar biomolecules are hydrophilic.
Question 8
A nonpolar hydrocarbon placed in water is generally described as:
A. Hydrophilic
B. Hydrophobic
C. Ionic
D. Highly acidic
Correct Answer: B. Hydrophobic
Rationale: Nonpolar hydrocarbons cannot form favorable interactions with water comparable to
water-water hydrogen bonding. They therefore tend to minimize their exposure to water.
Question 9
What does the term “aqueous solution” mean?
A. A solution containing only acids
B. A solution in which water is the solvent
C. A solution without ions
D. A solution containing no biomolecules
Correct Answer: B. A solution in which water is the solvent
Rationale: An aqueous solution is one in which water serves as the solvent. Many biochemical
reactions occur in aqueous environments.
Question 10
Which component of a solution is present in greater amount and dissolves another substance?
Portage Learning Questions & Verified Answers | 100% Pass
Guarantee - A+ Graded
CHEM 210 BIOCHEMISTRY
MODULE 2 — ORIGINAL PRACTICE EXAMINATION
Aqueous Reactions, Water, Acids, Bases, pH & Buffers
Academic Year 2026/2027
Institution: Portage Learning
Course Code: CHEM 210
Course: Biochemistry
Module: 2
Document Type: 200-Question Original Practice Examination with Answers & Detailed
Rationales
Academic Year: 2026/2027
TABLE OF CONTENTS
Section Questions
Introduction 1–30
Core Concepts 31–90
Applied Scenarios 91–140
Critical Thinking 141–175
Review Questions 176–200
Total Questions: 200
SECTION I — INTRODUCTION
Questions 1–30
Question 1
Which property of water is primarily responsible for its ability to dissolve many ionic and polar
substances?
,A. Low density
B. Polarity
C. Nonpolar covalent bonding
D. High molecular mass
Correct Answer: B. Polarity
Rationale: Water has an uneven distribution of electron density because oxygen is more
electronegative than hydrogen. This polarity allows water molecules to interact favorably with
ions and other polar molecules.
Question 2
What type of bond holds the hydrogen and oxygen atoms together within a water molecule?
A. Hydrogen bond
B. Ionic bond
C. Polar covalent bond
D. Metallic bond
Correct Answer: C. Polar covalent bond
Rationale: Oxygen and hydrogen share electrons, so the bond is covalent. Because oxygen
attracts the shared electrons more strongly, the O–H bond is polar.
Question 3
What intermolecular interaction occurs between the partially positive hydrogen of one water
molecule and the partially negative oxygen of another?
A. Ionic bond
B. Hydrogen bond
C. Peptide bond
D. Metallic bond
Correct Answer: B. Hydrogen bond
Rationale: Hydrogen bonding occurs when hydrogen covalently attached to an electronegative
atom interacts with an electronegative atom in another molecule. Water forms extensive
hydrogen-bond networks.
Question 4
,Which atom carries a partial negative charge in a water molecule?
A. Hydrogen
B. Oxygen
C. Both atoms equally
D. Neither atom
Correct Answer: B. Oxygen
Rationale: Oxygen has a greater electronegativity than hydrogen and attracts the shared bonding
electrons more strongly. Oxygen therefore has a partial negative charge, while hydrogen atoms
have partial positive charges.
Question 5
Why is water considered a polar molecule?
A. It contains only hydrogen atoms
B. It has ionic bonds
C. Its bent geometry and polar O–H bonds produce a net dipole
D. It has no electronegativity differences
Correct Answer: C. Its bent geometry and polar O–H bonds produce a net dipole
Rationale: Each O–H bond is polar, and the bent molecular geometry prevents the bond dipoles
from canceling. Consequently, water has a net molecular dipole.
Question 6
Which property of water helps organisms resist rapid temperature changes?
A. High specific heat
B. Low polarity
C. Low boiling point
D. Poor hydrogen bonding
Correct Answer: A. High specific heat
Rationale: Hydrogen bonding allows water to absorb substantial thermal energy before its
temperature rises significantly. This contributes to temperature stability in biological systems.
Question 7
, A substance that interacts favorably with water is generally described as:
A. Hydrophilic
B. Hydrophobic
C. Nonpolar
D. Amphoteric only
Correct Answer: A. Hydrophilic
Rationale: Hydrophilic substances have ionic or polar regions that interact favorably with water.
Many salts and polar biomolecules are hydrophilic.
Question 8
A nonpolar hydrocarbon placed in water is generally described as:
A. Hydrophilic
B. Hydrophobic
C. Ionic
D. Highly acidic
Correct Answer: B. Hydrophobic
Rationale: Nonpolar hydrocarbons cannot form favorable interactions with water comparable to
water-water hydrogen bonding. They therefore tend to minimize their exposure to water.
Question 9
What does the term “aqueous solution” mean?
A. A solution containing only acids
B. A solution in which water is the solvent
C. A solution without ions
D. A solution containing no biomolecules
Correct Answer: B. A solution in which water is the solvent
Rationale: An aqueous solution is one in which water serves as the solvent. Many biochemical
reactions occur in aqueous environments.
Question 10
Which component of a solution is present in greater amount and dissolves another substance?
