Free Practice Questions for MCAT Chem/Phys

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Key Facts: MCAT Chem/Phys Exam

59 questions in 95 minutes

Section Format

AAMC MCAT Content Outline 2024

Scored 118–132

Score Scale

AAMC MCAT Scoring 2024

General chemistry comprises ~30% of questions

Largest Content Domain

AAMC MCAT Content Outline 2024

~10 science passages per section

Passage Count

AAMC MCAT Test Structure

No calculator permitted on any MCAT section

Calculator Policy

AAMC Testing Rules 2024

Full MCAT total score range: 472–528

Total MCAT Score

AAMC MCAT Scoring Guide

The MCAT Chemical and Physical Foundations section has 59 questions in 95 minutes, scored 118–132 (AAMC, 2024). Content draws from general chemistry (~30%), introductory physics (~25%), first-semester biochemistry (~25%), organic chemistry (~15%), and introductory biology (~5%). Approximately 10 reading passages present ~44 passage-based questions, with the remainder as standalone discrete questions. Top MD programs (e.g., Harvard, Johns Hopkins) report mean Chem/Phys section scores of 131–132 for matriculants. Foundational Concept 4 covers physical principles (fluids, circuits, optics, nuclear physics) and Foundational Concept 5 covers chemical principles (bonding, equilibrium, kinetics, thermodynamics, electrochemistry). All content is framed in biological contexts such as cardiovascular fluid dynamics, enzyme kinetics, and acid–base physiology.

Sample MCAT Chem/Phys Practice Questions

Try these sample questions to review concepts for the MCAT Chem/Phys exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 121+ question experience with AI tutoring.

1An electron in a hydrogen atom transitions from n = 4 to n = 2. Using the Rydberg formula, the wavelength of the emitted photon is closest to: (R_H = 1.097 × 10⁷ m⁻¹)

A.122 nm

B.486 nm

C.656 nm

D.820 nm

Explanation: 1/λ = R_H(1/n₁² − 1/n₂²) = 1.097×10⁷(1/4 − 1/16) = 1.097×10⁷ × 3/16 ≈ 2.057×10⁶ m⁻¹; λ ≈ 486 nm. This is the blue-green Balmer series line (H_β).

2Which of the following correctly ranks the first ionization energies from lowest to highest? (I) Mg (II) Na (III) Al (IV) P

A.II < I < III < IV

B.II < III < I < IV

C.III < II < I < IV

D.I < III < II < IV

Explanation: Ionization energy increases across a period (left to right) but Al is anomalously lower than Mg because Al loses a 3p electron (easier than 3s). Order: Na < Al < Mg < P. That is II < III < I < IV.

3A solution is prepared by dissolving 4.0 g of NaOH (MW = 40 g/mol) in enough water to make 500 mL of solution. What is the pH of this solution?

A.1.0

B.7.0

C.12.0

D.13.0

Explanation: Moles NaOH = 4.0/40 = 0.10 mol. [OH⁻] = 0.10/0.500 = 0.20 M. pOH = −log(0.20) = 0.70. pH = 14 − 0.70 = 13.3 ≈ 13.

4At constant temperature, 2.0 L of an ideal gas at 3.0 atm is compressed to 1.0 L. What is the new pressure?

A.1.5 atm

B.3.0 atm

C.6.0 atm

D.9.0 atm

Explanation: Boyle's Law: P₁V₁ = P₂V₂. P₂ = (3.0 atm × 2.0 L)/1.0 L = 6.0 atm. Halving the volume doubles the pressure at constant T.

5The reaction A → B has ΔH° = −80 kJ/mol and ΔS° = −200 J/(mol·K). At what temperature (in K) does this reaction become non-spontaneous?

A.100 K

B.200 K

C.400 K

D.800 K

Explanation: Spontaneous when ΔG = ΔH − TΔS < 0. Crossover at ΔG = 0: T = ΔH/ΔS = (−80,000 J/mol)/(−200 J/(mol·K)) = 400 K. Above 400 K, ΔG > 0 (non-spontaneous).

6A buffer solution is made from acetic acid (pKa = 4.74) and sodium acetate. If [CH₃COOH] = 0.10 M and [CH₃COO⁻] = 0.20 M, what is the pH of the buffer?

A.4.44

B.4.74

C.5.04

D.5.44

Explanation: Henderson-Hasselbalch: pH = pKa + log([A⁻]/[HA]) = 4.74 + log(0.20/0.10) = 4.74 + log(2) = 4.74 + 0.30 = 5.04.

7For the equilibrium N₂(g) + 3H₂(g) ⇌ 2NH₃(g), at a given temperature Kc = 0.50. If the initial concentrations are [N₂] = 1.0 M, [H₂] = 1.0 M, and [NH₃] = 0.0 M, which way will the reaction proceed?

A.Forward, because Q < Kc

B.Backward, because Q > Kc

C.No change, because Q = Kc

D.Forward, because ΔG° < 0

Explanation: Q = [NH₃]²/([N₂][H₂]³) = 0²/(1.0 × 1.0³) = 0. Since Q = 0 < Kc = 0.50, the reaction proceeds forward to produce more NH₃.

8Passage: In a galvanic cell, zinc is oxidized at the anode and copper ions are reduced at the cathode. Standard reduction potentials are: Zn²⁺/Zn = −0.76 V and Cu²⁺/Cu = +0.34 V. What is the standard cell potential (E°cell) for this galvanic cell?

A.−1.10 V

B.−0.42 V

C.+0.42 V

D.+1.10 V

Explanation: E°cell = E°cathode − E°anode = (+0.34) − (−0.76) = +1.10 V. Positive E°cell confirms the reaction is spontaneous as written.

9Passage: In a galvanic cell, zinc is oxidized at the anode and copper ions are reduced at the cathode. Standard reduction potentials are: Zn²⁺/Zn = −0.76 V and Cu²⁺/Cu = +0.34 V. Using ΔG° = −nFE°, and given that n = 2 and F = 96,485 C/mol, what is ΔG° for this cell reaction (approximately)?

A.+212 kJ/mol

B.−106 kJ/mol

C.−212 kJ/mol

D.+106 kJ/mol

Explanation: ΔG° = −nFE° = −(2)(96,485)(1.10) ≈ −212,267 J/mol ≈ −212 kJ/mol. The large negative value confirms spontaneity.

10The rate law for a reaction is: rate = k[A]²[B]. If the concentration of A is doubled while B is held constant, how does the rate change?

A.Rate doubles

B.Rate triples

C.Rate increases by a factor of 4

D.Rate increases by a factor of 8

Explanation: The reaction is second order in A. If [A] is doubled: rate_new = k(2[A])²[B] = 4k[A]²[B] = 4 × rate_original. Rate increases by factor of 4.

About the MCAT Chem/Phys Exam

The MCAT Chemical and Physical Foundations of Biological Systems section is the first of four sections on the MCAT exam. It contains 59 questions answered in 95 minutes and is scored on a scale of 118–132. Questions are organized around two Foundational Concepts: FC4 (physical principles in living systems, ~40%) and FC5 (chemical interactions and reactions, ~60%). All questions are presented in a biological or biomedical context.

Exam sponsor: Association of American Medical Colleges (AAMC). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Questions

59 questions

Time Limit

95 minutes

Passing Score

Scored 118–132 (competitive target: 127–132)

Exam / Certification Fees

Part of $355 MCAT registration fee (2026 standard U.S./Canada fee)

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

~30%

General Chemistry

Atomic structure, bonding, stoichiometry, gases, solutions, acids/bases, equilibrium, thermodynamics, kinetics, and electrochemistry — all framed in biological contexts.

~25%

Physics

Kinematics, forces, energy/work, momentum, fluids, thermodynamics, waves/sound, electrostatics, circuits, light/optics, and atomic/nuclear physics.

~25%

Biochemistry

Amino acids, proteins, enzyme kinetics (Michaelis–Menten, inhibition types), lipids, and biological applications of physical/chemical principles.

~15%

Organic Chemistry

Functional groups, isomerism, stereochemistry, reaction mechanisms (SN1/SN2, E1/E2, addition, oxidation/reduction), separations, and spectroscopy (IR, NMR, MS).

~5%

Introductory Biology (contextual)

Biological system contexts for chemical/physical principles — cardiovascular, respiratory, renal, and cellular topics tested through a chemistry or physics lens.

Preparing for the MCAT Chem/Phys Exam

What You Need to Know

Passing score: Scored 118–132 (competitive target: 127–132)
Exam length: 59 questions
Time limit: 95 minutes
Exam / certification fees: Part of $355 MCAT registration fee (2026 standard U.S./Canada fee) Official sources

Using Our Practice Resources

Work through all 121 available questions
Review every answer and explanation
Track weak areas and revisit them
Use our AI tutor for tough concepts

MCAT Chem/Phys: Suggested Study Strategy

1Master the Henderson-Hasselbalch equation, Nernst equation, and Michaelis-Menten equation — these appear frequently in passage-based and discrete questions.

2No calculator is allowed: practice mental math with powers of 10, log approximations (log 2 ≈ 0.30, log 3 ≈ 0.48), and quick unit conversions.

3For passage-based questions, read the question stem first, then skim the passage for the specific data needed — avoid reading every word before checking the questions.

4Use dimensional analysis to verify your answer in calculation problems; wrong units eliminate wrong answers quickly.

5Review Foundational Concepts 4 and 5 from the AAMC content outline and ensure you can apply every listed topic in a biological context (e.g., Bernoulli's equation applied to stenosed arteries, osmotic pressure in red blood cells).

Frequently Asked Questions

How long is the MCAT Chemical and Physical Foundations section?

The section is 95 minutes long and contains 59 questions. It is the first of four MCAT sections; the full exam takes about 7.5 hours on test day including breaks.

What score range does the MCAT Chem/Phys section use?

Each MCAT section is scored 118–132, with a midpoint of 125. The total MCAT score (all four sections) ranges 472–528. Most competitive medical schools look for 127–132 on the Chem/Phys section.

What subjects are tested in the MCAT Chemical and Physical Foundations section?

The section draws from general chemistry (~30%), introductory physics (~25%), first-semester biochemistry (~25%), organic chemistry (~15%), and introductory biology (~5%). All topics are tested in biological or biomedical contexts.

How many passages are in the MCAT Chem/Phys section?

The section contains approximately 10 science passages (each with 4–6 questions) plus discrete (standalone) questions that are not passage-based. Passages may include experimental data, graphs, equations, and research scenarios.

Is a calculator allowed on the MCAT Chemical and Physical Foundations section?

No. The MCAT does not permit calculators for any section. Numerical calculations are designed to be solvable with mental math or simple arithmetic — knowledge of approximation strategies and key constants is essential.

How hard is the MCAT Chem/Phys section compared to undergraduate courses?

Questions are application-level, not recall-level. You must integrate knowledge across general chemistry, physics, and biochemistry in novel biological contexts. The AAMC designs questions around Scientific Inquiry and Reasoning Skills (SIRS): knowledge application, scientific reasoning, data interpretation, and research design.