CHEM121 Foundations of General
Chemistry
(Module 1 – 8)
Final Exam Review
(Questions & Solutions)
2025
1
, 1. Which of the following is the SI base unit for mass?
A. Gram
B. Kilogram
C. Milligram
D. Atomic mass unit
ANS: B
Rationale: The kilogram is the SI base unit of mass, although in most
chemistry lab work, masses are frequently measured in grams (1 kg =
1000 g). However, for SI standardization, the kilogram is used.
2. Dalton’s atomic theory proposes that:
A. Atoms can be subdivided into smaller particles that are identical in all
respects
B. Atoms of a given element are identical in mass and properties
C. Atoms are created during chemical reactions
D. Atoms of different elements can combine into compounds randomly
ANS: B
Rationale: Dalton’s theory states that atoms of a specific element have
identical masses and properties, and that compounds form when atoms
combine in fixed ratios.
3. Moving from left to right across a period in the periodic table, the
atomic radius generally:
A. Increases
B. Decreases
C. Remains constant
D. First increases then decreases
ANS: B
Rationale: As you move across a period, the increased nuclear charge
pulls electrons closer to the nucleus, decreasing the atomic radius.
2
, 4. Which of the following is the correct formula for calcium nitrate?
A. Ca(NO₃)₂
B. CaNO₃
C. Ca₃(NO₃)₂
D. Ca(NO₃)₃
ANS: A
Rationale: Calcium has a 2+ charge and nitrate (NO₃⁻) has a 1– charge.
Two nitrate ions are required to balance one Ca²⁺ ion.
5. When naming an ionic compound composed of magnesium and
chloride, the correct name is:
A. Magnesium dichloride
B. Magnesium chloride
C. Magnesium (II) chloride
D. Magnesium chloride (II)
ANS: B
Rationale: Magnesium forms a 2+ ion and chloride forms a 1– ion. The
formula MagCl₂ is written without Roman numerals because
magnesium’s oxidation state is fixed.
---
Section II. Reaction Balancing, Stoichiometry, and Composition
6. In balancing a redox reaction in acidic solution, which method is
most appropriate?
A. Inspection method
B. Half-reaction method
C. Ion-electron method
D. Both B and C
ANS: D
Rationale: The half-reaction (ion-electron) method is the standard
approach used to balance redox reactions under acidic (or basic)
conditions by separately balancing oxidation and reduction half-
reactions.
3
Chemistry
(Module 1 – 8)
Final Exam Review
(Questions & Solutions)
2025
1
, 1. Which of the following is the SI base unit for mass?
A. Gram
B. Kilogram
C. Milligram
D. Atomic mass unit
ANS: B
Rationale: The kilogram is the SI base unit of mass, although in most
chemistry lab work, masses are frequently measured in grams (1 kg =
1000 g). However, for SI standardization, the kilogram is used.
2. Dalton’s atomic theory proposes that:
A. Atoms can be subdivided into smaller particles that are identical in all
respects
B. Atoms of a given element are identical in mass and properties
C. Atoms are created during chemical reactions
D. Atoms of different elements can combine into compounds randomly
ANS: B
Rationale: Dalton’s theory states that atoms of a specific element have
identical masses and properties, and that compounds form when atoms
combine in fixed ratios.
3. Moving from left to right across a period in the periodic table, the
atomic radius generally:
A. Increases
B. Decreases
C. Remains constant
D. First increases then decreases
ANS: B
Rationale: As you move across a period, the increased nuclear charge
pulls electrons closer to the nucleus, decreasing the atomic radius.
2
, 4. Which of the following is the correct formula for calcium nitrate?
A. Ca(NO₃)₂
B. CaNO₃
C. Ca₃(NO₃)₂
D. Ca(NO₃)₃
ANS: A
Rationale: Calcium has a 2+ charge and nitrate (NO₃⁻) has a 1– charge.
Two nitrate ions are required to balance one Ca²⁺ ion.
5. When naming an ionic compound composed of magnesium and
chloride, the correct name is:
A. Magnesium dichloride
B. Magnesium chloride
C. Magnesium (II) chloride
D. Magnesium chloride (II)
ANS: B
Rationale: Magnesium forms a 2+ ion and chloride forms a 1– ion. The
formula MagCl₂ is written without Roman numerals because
magnesium’s oxidation state is fixed.
---
Section II. Reaction Balancing, Stoichiometry, and Composition
6. In balancing a redox reaction in acidic solution, which method is
most appropriate?
A. Inspection method
B. Half-reaction method
C. Ion-electron method
D. Both B and C
ANS: D
Rationale: The half-reaction (ion-electron) method is the standard
approach used to balance redox reactions under acidic (or basic)
conditions by separately balancing oxidation and reduction half-
reactions.
3
