MCAT Exam Prep 2026-2027 | Complete Review
and Preparation Guide with All Four Sections/ Full-
Length Practice Questions and Step-by-Step
Explanations to Ace the MCAT Exam
MCAT Practice Questions - All Four Sections
This comprehensive practice set contains 230 questions covering all four sections of the MCAT
exam. Each question includes the correct answer and a detailed rationale.
Section 1: Chemical and Physical Foundations of Biological Systems (60 Questions)
Question 1
What is the proper formula for sodium sulfate?
A. NaSO₄
B. Na₂SO₄
C. Na(SO₄)₂
D. Na₃SO₄
Correct Answer: B. Na₂SO₄
Rationale: Sodium sulfate consists of two sodium ions (Na⁺) and one sulfate ion (SO₄²⁻). To
balance the charges, two sodium ions (+2 total) are needed to balance the -2 charge of the
sulfate ion. This gives the formula Na₂SO₄ .
Question 2
The human circulatory system is considered to be a ___ loop that has a ___ flow rate.
A. open; constant
B. closed; nonconstant
C. closed; constant
D. open; nonconstant
,Correct Answer: B. closed; nonconstant
Rationale: The human circulatory system is a closed loop system where blood remains within
vessels. The flow rate is nonconstant because it varies with cardiac output, vessel diameter, and
other factors .
Question 3
Which of the following types of bonds is NOT involved in synthesizing double-stranded DNA?
A. β-N-glycosidic linkages
B. Disulfide bridges
C. Phosphodiester bonds
D. Hydrogen bonds
Correct Answer: B. Disulfide bridges
Rationale: Disulfide bridges are covalent bonds formed between cysteine residues in proteins;
they are not involved in DNA synthesis. DNA synthesis involves phosphodiester bonds between
nucleotides, hydrogen bonds between complementary base pairs, and β-N-glycosidic linkages
connecting the base to the sugar .
Question 4
What is the approximate height to which ethanol (specific gravity = 0.780) will rise in a
barometer tube open to the atmosphere? Atmospheric pressure = 1.01 × 10⁵ Pa, g = 9.81
m/s², density of water = 1000 kg/m³
A. 13.2 m
B. 8.3 m
C. 4.2 m
D. 7.6 cm
Correct Answer: A. 13.2 m
Rationale: The pressure at equilibrium equals atmospheric pressure. Using P = ρgh, first
calculate ethanol density: ρ = 0.780 × 1000 = 780 kg/m³. Then h = P/(ρg) =
(1.01×10⁵)/(780×9.81) = 13.2 m .
Question 5
,A tank is filled with water to a depth of 2 m, and oil with a density of 800 kg/m³ is added until
the final depth is 4 m. What is the pressure at the bottom of the tank? (Ignore atmospheric
pressure, g = 10 m/s²)
A. 20,000 Pa
B. 32,000 Pa
C. 36,000 Pa
D. 40,000 Pa
Correct Answer: C. 36,000 Pa
Rationale: Total pressure = P_water + P_oil = (ρ_water × g × h_water) + (ρ_oil × g × h_oil) =
(1000×10×2) + (800×10×2) = 20,000 + 16,000 = 36,000 Pa .
Question 6
A projectile is launched at an angle above the horizontal. If the total time of flight is 8
seconds, what is the maximum height reached? (g = 10 m/s²)
A. 40 m
B. 80 m
C. 120 m
D. 160 m
Correct Answer: B. 80 m
Rationale: The time to reach maximum height is half the total flight time, or 4 seconds. Using y
= (1/2)gt² for the downward journey from max height: y = (1/2)(10)(4²) = 80 m. The launch angle
does not affect this calculation .
Question 7
Which of the following best characterizes the differences between fatty acids and
phospholipids?
A. Fatty acids have two tails and form micelles; phospholipids have one tail and form
membranes
B. Fatty acids have two tails and form membranes; phospholipids have two tails and form
micelles
C. Fatty acids have one tail and form micelles; phospholipids have two tails and form
membranes
D. Fatty acids have one tail and form membranes; phospholipids have one tail and form micelles
, Correct Answer: C. Fatty acids have one tail and form micelles; phospholipids have two tails
and form membranes
Rationale: Fatty acids have a single hydrocarbon tail and spontaneously form spherical micelles.
Phospholipids have two hydrocarbon tails and organize into bilayers that form membranes .
Question 8
Compound J reacts with Compound K at 20°C to form a mixture of two products, L (20%) and
M (80%). When the reaction is performed at 60°C, compounds L and M are formed in 80% and
20% yields. When the reaction mixture obtained at 20°C is heated to 60°C and allowed to
stand overnight, the composition slowly changes to 80% L/20% M. Which statement is most
consistent with this information?
A. An equilibrium mixture of L and M is obtained at 60°C
B. The activation energy for formation of L is lower than that for M
C. M is more stable than L
D. L is formed faster than M
Correct Answer: A. An equilibrium mixture of L and M is obtained at 60°C
Rationale: The composition remains constant at 80% L/20% M when maintained at 60°C over a
long period, indicating this represents the equilibrium product composition at that temperature.
This demonstrates L is more stable than M .
Question 9
A tank is filled to a depth of 3 m with water. What is the gauge pressure at the bottom?
(ρ_water = 1000 kg/m³, g = 10 m/s²)
A. 10,000 Pa
B. 20,000 Pa
C. 30,000 Pa
D. 40,000 Pa
Correct Answer: C. 30,000 Pa
Rationale: Gauge pressure P = ρgh = (1000)(10)(3) = 30,000 Pa. Gauge pressure does not include
atmospheric pressure .
Question 10
and Preparation Guide with All Four Sections/ Full-
Length Practice Questions and Step-by-Step
Explanations to Ace the MCAT Exam
MCAT Practice Questions - All Four Sections
This comprehensive practice set contains 230 questions covering all four sections of the MCAT
exam. Each question includes the correct answer and a detailed rationale.
Section 1: Chemical and Physical Foundations of Biological Systems (60 Questions)
Question 1
What is the proper formula for sodium sulfate?
A. NaSO₄
B. Na₂SO₄
C. Na(SO₄)₂
D. Na₃SO₄
Correct Answer: B. Na₂SO₄
Rationale: Sodium sulfate consists of two sodium ions (Na⁺) and one sulfate ion (SO₄²⁻). To
balance the charges, two sodium ions (+2 total) are needed to balance the -2 charge of the
sulfate ion. This gives the formula Na₂SO₄ .
Question 2
The human circulatory system is considered to be a ___ loop that has a ___ flow rate.
A. open; constant
B. closed; nonconstant
C. closed; constant
D. open; nonconstant
,Correct Answer: B. closed; nonconstant
Rationale: The human circulatory system is a closed loop system where blood remains within
vessels. The flow rate is nonconstant because it varies with cardiac output, vessel diameter, and
other factors .
Question 3
Which of the following types of bonds is NOT involved in synthesizing double-stranded DNA?
A. β-N-glycosidic linkages
B. Disulfide bridges
C. Phosphodiester bonds
D. Hydrogen bonds
Correct Answer: B. Disulfide bridges
Rationale: Disulfide bridges are covalent bonds formed between cysteine residues in proteins;
they are not involved in DNA synthesis. DNA synthesis involves phosphodiester bonds between
nucleotides, hydrogen bonds between complementary base pairs, and β-N-glycosidic linkages
connecting the base to the sugar .
Question 4
What is the approximate height to which ethanol (specific gravity = 0.780) will rise in a
barometer tube open to the atmosphere? Atmospheric pressure = 1.01 × 10⁵ Pa, g = 9.81
m/s², density of water = 1000 kg/m³
A. 13.2 m
B. 8.3 m
C. 4.2 m
D. 7.6 cm
Correct Answer: A. 13.2 m
Rationale: The pressure at equilibrium equals atmospheric pressure. Using P = ρgh, first
calculate ethanol density: ρ = 0.780 × 1000 = 780 kg/m³. Then h = P/(ρg) =
(1.01×10⁵)/(780×9.81) = 13.2 m .
Question 5
,A tank is filled with water to a depth of 2 m, and oil with a density of 800 kg/m³ is added until
the final depth is 4 m. What is the pressure at the bottom of the tank? (Ignore atmospheric
pressure, g = 10 m/s²)
A. 20,000 Pa
B. 32,000 Pa
C. 36,000 Pa
D. 40,000 Pa
Correct Answer: C. 36,000 Pa
Rationale: Total pressure = P_water + P_oil = (ρ_water × g × h_water) + (ρ_oil × g × h_oil) =
(1000×10×2) + (800×10×2) = 20,000 + 16,000 = 36,000 Pa .
Question 6
A projectile is launched at an angle above the horizontal. If the total time of flight is 8
seconds, what is the maximum height reached? (g = 10 m/s²)
A. 40 m
B. 80 m
C. 120 m
D. 160 m
Correct Answer: B. 80 m
Rationale: The time to reach maximum height is half the total flight time, or 4 seconds. Using y
= (1/2)gt² for the downward journey from max height: y = (1/2)(10)(4²) = 80 m. The launch angle
does not affect this calculation .
Question 7
Which of the following best characterizes the differences between fatty acids and
phospholipids?
A. Fatty acids have two tails and form micelles; phospholipids have one tail and form
membranes
B. Fatty acids have two tails and form membranes; phospholipids have two tails and form
micelles
C. Fatty acids have one tail and form micelles; phospholipids have two tails and form
membranes
D. Fatty acids have one tail and form membranes; phospholipids have one tail and form micelles
, Correct Answer: C. Fatty acids have one tail and form micelles; phospholipids have two tails
and form membranes
Rationale: Fatty acids have a single hydrocarbon tail and spontaneously form spherical micelles.
Phospholipids have two hydrocarbon tails and organize into bilayers that form membranes .
Question 8
Compound J reacts with Compound K at 20°C to form a mixture of two products, L (20%) and
M (80%). When the reaction is performed at 60°C, compounds L and M are formed in 80% and
20% yields. When the reaction mixture obtained at 20°C is heated to 60°C and allowed to
stand overnight, the composition slowly changes to 80% L/20% M. Which statement is most
consistent with this information?
A. An equilibrium mixture of L and M is obtained at 60°C
B. The activation energy for formation of L is lower than that for M
C. M is more stable than L
D. L is formed faster than M
Correct Answer: A. An equilibrium mixture of L and M is obtained at 60°C
Rationale: The composition remains constant at 80% L/20% M when maintained at 60°C over a
long period, indicating this represents the equilibrium product composition at that temperature.
This demonstrates L is more stable than M .
Question 9
A tank is filled to a depth of 3 m with water. What is the gauge pressure at the bottom?
(ρ_water = 1000 kg/m³, g = 10 m/s²)
A. 10,000 Pa
B. 20,000 Pa
C. 30,000 Pa
D. 40,000 Pa
Correct Answer: C. 30,000 Pa
Rationale: Gauge pressure P = ρgh = (1000)(10)(3) = 30,000 Pa. Gauge pressure does not include
atmospheric pressure .
Question 10
