CHEM 120 EXAM 3 (CHAMBERLAIN) NEWEST 2026
ACTUAL EXAM TEST BANK| CHEM 120
INTRODUCTION TO GENERAL, ORGANIC &
BIOLOGICAL CHEMISTRY EXAM 3 REVIEW WITH 300
REAL EXAM QUESTIONS AND CORRECT VERIFIED
ANSWERS/ ALREADY GRADED A+ (MOST RECENT!!)
Q1. What is the molarity of a solution containing 2.5 moles of
NaCl dissolved in enough water to make 0.500 L of solution?
A) 0.20 M
B) 1.25 M
C) 5.0 M
D) 12.5 M
Correct Answer: C
Rationale: Molarity (M) = moles of solute / liters of solution =
2.5 mol / 0.500 L = 5.0 M.
Q2. Which of the following is a strong base?
A) NH₃ (ammonia)
B) KOH (potassium hydroxide)
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,C) CH₃OH (methanol)
D) H₂CO₃ (carbonic acid)
Correct Answer: B
Rationale: KOH is a strong base that completely dissociates into
K⁺ and OH⁻ in water. NH₃ is a weak base. CH₃OH is neutral.
H₂CO₃ is a weak acid.
Q3. According to Le Châtelier's principle, increasing the
temperature of an exothermic reaction will:
A) Shift the equilibrium toward the products
B) Shift the equilibrium toward the reactants
C) Have no effect on equilibrium
D) Increase the activation energy
Correct Answer: B
Rationale: For an exothermic reaction (heat is a product), adding
heat shifts equilibrium toward the reactants (left), favoring the
reverse reaction.
Q4. How many grams of glucose (C₆H₁₂O₆, molar mass
180.16 g/mol) are needed to prepare 250.0 mL of a 0.300 M
2
,solution?
A) 5.40 g
B) 13.5 g
C) 54.0 g
D) 135 g
Correct Answer: B
Rationale: Moles = M × L = 0.300 mol/L × 0.250 L = 0.0750
mol. Grams = 0.0750 mol × 180.16 g/mol = 13.51 g ≈ 13.5 g.
Q5. Which functional group is present in a carboxylic acid?
A) –OH
B) –NH₂
C) –COOH
D) –CHO
Correct Answer: C
Rationale: Carboxylic acids contain the carboxyl group (–
COOH). –OH is alcohol, –NH₂ is amine, –CHO is aldehyde.
Q6. A solution has a pH of 3.5. What is the hydronium ion
concentration [H₃O⁺]?
3
, A) 3.5 × 10⁻¹ M
B) 3.2 × 10⁻⁴ M
C) 3.2 × 10⁻¹¹ M
D) 1.0 × 10⁻⁷ M
Correct Answer: B
Rationale: [H₃O⁺] = 10⁻ᵖᴴ = 10⁻³·⁵ = 3.16 × 10⁻⁴ M. pH = –
log[H₃O⁺].
Q7. Which of the following is a saturated hydrocarbon?
A) Ethene (C₂H₄)
B) Ethane (C₂H₆)
C) Ethyne (C₂H₂)
D) Benzene (C₆H₆)
Correct Answer: B
Rationale: Saturated hydrocarbons (alkanes) have only single
bonds and maximum number of H atoms. Ethane (C₂H₆) is an
alkane. Ethene has double bond, ethyne has triple bond.
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ACTUAL EXAM TEST BANK| CHEM 120
INTRODUCTION TO GENERAL, ORGANIC &
BIOLOGICAL CHEMISTRY EXAM 3 REVIEW WITH 300
REAL EXAM QUESTIONS AND CORRECT VERIFIED
ANSWERS/ ALREADY GRADED A+ (MOST RECENT!!)
Q1. What is the molarity of a solution containing 2.5 moles of
NaCl dissolved in enough water to make 0.500 L of solution?
A) 0.20 M
B) 1.25 M
C) 5.0 M
D) 12.5 M
Correct Answer: C
Rationale: Molarity (M) = moles of solute / liters of solution =
2.5 mol / 0.500 L = 5.0 M.
Q2. Which of the following is a strong base?
A) NH₃ (ammonia)
B) KOH (potassium hydroxide)
1
,C) CH₃OH (methanol)
D) H₂CO₃ (carbonic acid)
Correct Answer: B
Rationale: KOH is a strong base that completely dissociates into
K⁺ and OH⁻ in water. NH₃ is a weak base. CH₃OH is neutral.
H₂CO₃ is a weak acid.
Q3. According to Le Châtelier's principle, increasing the
temperature of an exothermic reaction will:
A) Shift the equilibrium toward the products
B) Shift the equilibrium toward the reactants
C) Have no effect on equilibrium
D) Increase the activation energy
Correct Answer: B
Rationale: For an exothermic reaction (heat is a product), adding
heat shifts equilibrium toward the reactants (left), favoring the
reverse reaction.
Q4. How many grams of glucose (C₆H₁₂O₆, molar mass
180.16 g/mol) are needed to prepare 250.0 mL of a 0.300 M
2
,solution?
A) 5.40 g
B) 13.5 g
C) 54.0 g
D) 135 g
Correct Answer: B
Rationale: Moles = M × L = 0.300 mol/L × 0.250 L = 0.0750
mol. Grams = 0.0750 mol × 180.16 g/mol = 13.51 g ≈ 13.5 g.
Q5. Which functional group is present in a carboxylic acid?
A) –OH
B) –NH₂
C) –COOH
D) –CHO
Correct Answer: C
Rationale: Carboxylic acids contain the carboxyl group (–
COOH). –OH is alcohol, –NH₂ is amine, –CHO is aldehyde.
Q6. A solution has a pH of 3.5. What is the hydronium ion
concentration [H₃O⁺]?
3
, A) 3.5 × 10⁻¹ M
B) 3.2 × 10⁻⁴ M
C) 3.2 × 10⁻¹¹ M
D) 1.0 × 10⁻⁷ M
Correct Answer: B
Rationale: [H₃O⁺] = 10⁻ᵖᴴ = 10⁻³·⁵ = 3.16 × 10⁻⁴ M. pH = –
log[H₃O⁺].
Q7. Which of the following is a saturated hydrocarbon?
A) Ethene (C₂H₄)
B) Ethane (C₂H₆)
C) Ethyne (C₂H₂)
D) Benzene (C₆H₆)
Correct Answer: B
Rationale: Saturated hydrocarbons (alkanes) have only single
bonds and maximum number of H atoms. Ethane (C₂H₆) is an
alkane. Ethene has double bond, ethyne has triple bond.
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