📋 AP Chemistry Formula Sheet Overview
The College Board provides a 3-page reference document during the AP Chemistry exam containing equations, constants, unit conversions, and a complete periodic table. You'll have access to it for both sections of the exam.
Good news for AP Chemistry students: you don't have to memorize every single equation. The College Board provides an official AP Chemistry formula sheet during the exam that includes key equations and constants you'll need to solve problems.
But here's the catch—having the formulas in front of you isn't enough. You need to understand when and how to use each one. This guide covers everything on the AP Chemistry formula sheet, what's notably missing that you do need to memorize, and strategies for making the most of this valuable resource on exam day.
📋 What's In This Guide
What Is the AP Chemistry Formula Sheet?
The AP Chemistry formula sheet (officially called the “Equations and Constants Sheet”) is a three-page reference document provided by the College Board during the AP Chemistry exam. It's updated periodically—the current version is effective for the 2025 and 2026 exams.
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Page 1
Periodic Table of Elements
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Page 2
Units, Conversions, Atomic Structure, Gases & Solutions
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Page 3
Kinetics, Equilibrium, Thermodynamics & Electrochemistry
When Do You Get Access?
You'll receive the formula sheet at the beginning of the exam and can use it throughout:
✅ Section I: Multiple Choice
60 questions, 90 minutes
Formula sheet provided
✅ Section II: Free Response
7 questions, 105 minutes
Formula sheet provided
💡 Pro Tip
You can use blank space on the formula sheet for scratch work during the exam. Just remember—proctors collect it at the end, so you can't keep it.
The Periodic Table
The first page of your AP Chemistry formula sheet contains a complete periodic table with:
Atomic Numbers
The number of protons in each element's nucleus
Element Symbols
Standard one or two-letter abbreviations
Atomic Masses
Average atomic mass in atomic mass units (amu)
Group and Period Numbers
Columns (1-18) and rows for identifying element families
⚠️ What You Still Need to Know
The periodic table doesn't tell you periodic trends (electronegativity, atomic radius, ionization energy), electron configurations, or common oxidation states. You need to memorize these concepts and understand how to derive them from position on the table.
Units, Conversions & Metric Prefixes
The formula sheet provides essential unit symbols, conversions, and metric prefixes you'll use throughout the exam.
Unit Symbols
| Unit | Symbol |
|---|---|
| gram | g |
| mole | mol |
| liter | L |
| meter | m |
| second | s |
| atmosphere | atm |
| kelvin | K |
| joule | J |
Key Unit Conversions
Metric Prefixes
| Factor | Prefix | Symbol |
|---|---|---|
| 10⁹ | giga | G |
| 10⁶ | mega | M |
| 10³ | kilo | k |
| 10⁻² | centi | c |
| 10⁻³ | milli | m |
| 10⁻⁶ | micro | μ |
| 10⁻⁹ | nano | n |
| 10⁻¹² | pico | p |
Atomic Structure Equations
These equations relate to energy, light, and atomic interactions:
E = hν
Planck's Equation: Energy of a photon equals Planck's constant times frequency
c = λν
Wave Equation: Speed of light equals wavelength times frequency
Fcoulombic ∝ q₁q₂/r²
Coulombic Force: Force between charges is proportional to product of charges divided by distance squared
Constants Provided
Gases, Liquids & Solutions Equations
This section covers the most commonly used equations for gas laws, solutions, and related calculations.
P₁V₁/T₁ = P₂V₂/T₂
Combined Gas Law
PV = nRT
Ideal Gas Law
PA = Ptotal × XA
Dalton's Law of Partial Pressures (where XA = moles A / total moles)
Ptotal = PA + PB + PC + …
Total Pressure
n = m/M
Moles = mass / molar mass
D = m/V
Density = mass / volume
KE = ½mv²
Kinetic Energy
M = nsolute/Lsolution
Molarity
A = εbc
Beer-Lambert Law (A = absorbance, ε = molar absorptivity, b = path length, c = concentration)
Gas Constants Provided
Kinetics Equations
These equations describe reaction rates and how concentrations change over time:
[A]t − [A]0 = −kt
Zero-Order Integrated Rate Law
ln[A]t − ln[A]0 = −kt
First-Order Integrated Rate Law
1/[A]t − 1/[A]0 = kt
Second-Order Integrated Rate Law
t½ = 0.693/k
Half-Life (First-Order)
Equilibrium Equations
The equilibrium section includes expressions for various equilibrium constants and acid-base calculations:
Kc = [C]c[D]d / [A]a[B]b
Equilibrium Constant Expression (for aA + bB ⇌ cC + dD)
Kw = [H₃O⁺][OH⁻] = 1.0 × 10⁻¹⁴ at 25°C
Ion Product of Water
pH = −log[H₃O⁺], pOH = −log[OH⁻]
pH and pOH Definitions
pKw = 14 = pH + pOH at 25°C
Relationship between pH and pOH
Ka = [H₃O⁺][A⁻]/[HA], Kb = [OH⁻][HB⁺]/[B]
Acid and Base Dissociation Constants
Kw = Ka × Kb, pKw = pKa + pKb
Conjugate Acid-Base Relationship
pH = pKa + log([A⁻]/[HA])
Henderson-Hasselbalch Equation
Thermodynamics & Electrochemistry Equations
These equations cover energy changes, spontaneity, and electrochemical calculations:
q = mcΔT
Heat Equation (q = heat, m = mass, c = specific heat, ΔT = temperature change)
ΔH°rxn = ΣΔH°f(products) − ΣΔH°f(reactants)
Enthalpy of Reaction
ΔS°rxn = ΣS°products − ΣS°reactants
Entropy of Reaction
ΔG° = ΔH° − TΔS°
Gibbs Free Energy
ΔG° = −RT ln K = −nFE°
Gibbs Free Energy Relationships
I = q/t
Current (I = amperes, q = coulombs, t = seconds)
Ecell = E°cell − (RT/nF)ln Q
Nernst Equation
Important Formulas NOT on the Sheet
The AP Chemistry formula sheet is helpful, but it doesn't include everything. Here are key equations and concepts you must memorize:
Rate = k[A]m[B]n
Rate Law: Relationship between reaction rate and reactant concentrations. The exponents m and n are determined experimentally.
% Error = |Actual − Theoretical| / Theoretical × 100
Percent Error: Used to evaluate experimental accuracy compared to accepted values.
% Yield = Actual Yield / Theoretical Yield × 100
Percent Yield: Efficiency of a chemical reaction.
% Composition = (Mass of element / Molar mass) × 100
Percent Composition: Mass percentage of each element in a compound.
M₁V₁ = M₂V₂
Dilution Equation: Relates molarity and volume before and after dilution.
Other Concepts to Memorize
How to Use the Formula Sheet Effectively
Having the AP Chemistry formula sheet doesn't guarantee success—you need to know how to use it. Here are proven strategies:
Learn Every Formula Before Exam Day
The College Board doesn't include anything unnecessary. If it's on the sheet, there's a good chance you'll need it. Understand what each variable represents and when to apply each equation.
Practice with the Actual Sheet
Download and print the official formula sheet from College Board. Use it for all your practice tests and homework so you know exactly where to find each equation under timed conditions.
Know the Periodic Table Inside and Out
You'll reference it constantly. Know how to use group numbers to determine valence electrons, predict bonding, and understand periodic trends—even though trends aren't explicitly listed.
Use Your Calculator Wisely
You can use a graphing calculator on free-response questions (but not multiple choice). Program commonly used constants into your calculator, but don't rely on it—understand the concepts behind the calculations.
Focus on Problem Recognition
The hardest part isn't plugging numbers into formulas—it's knowing which formula to use. Practice identifying problem types and matching them to the correct equations.
Preparing for the AP Chemistry Exam
Success on the AP Chemistry exam requires consistent study throughout the year. Here are some resources to help:
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Review Books
Check out our AP Chemistry review books for comprehensive study guides and practice tests.
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Time Management
Use effective time management strategies to balance AP Chemistry with your other courses.
Once exams are over, you can sell your AP books to recoup costs and help future students. And if you're curious about exam costs, see our AP exam fees guide.
📥 Download the Official AP Chemistry Formula Sheet
Get the official 2025-2026 AP Chemistry Equations and Constants sheet directly from College Board:
📚 Related Resources
- AP Chemistry Review Books — Best prep books for the exam
- AP Exam Schedule 2026 — Find your test date
- Understanding AP Scores — What scores mean for college credit
- AP Exam Fees — Costs and fee reductions
- View Your AP Scores — How to check results in July
Master the Formula Sheet, Ace the Exam
The AP Chemistry formula sheet is a powerful tool—but only if you know how to use it. Practice with it throughout the year, understand when to apply each equation, and memorize what's not included.
Good luck on your AP Chemistry exam! 🧪
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