AP Chemistry cheat sheet: a unit-by-unit cram chart.
You cannot take a cheat sheet into the AP Chemistry exam: College Board hands you a printed periodic table and equations sheet, and nothing else. So this AP Chemistry cram chart is built for the week before — one row for each of the nine AP Chemistry units, pairing the key idea with the must-know relationship and the mistake that costs students points.
What an AP Chemistry cheat sheet is (and what you can’t bring)
A cheat sheet here means a condensed, high-yield study tool, not something you carry into the exam. College Board’s exam-day rules put notes, books, notebooks, dictionaries and highlighters on the prohibited list, and reference guides are barred as well, because the proctor issues the only reference material you are allowed. A student found with a prohibited item can be dismissed from the exam and have their score canceled, with no retest.
So treat this page as what you review the night before, not what you take in. What makes it more useful than the raw equation list is context: the one idea each unit is really testing, and the slip that turns a correct setup into a wrong answer.
The unit-by-unit cram chart
Nine units, each boiled down to the idea, the must-know relationship, and the trap to dodge. The percentage on each row is College Board’s exam weighting for that unit on the multiple-choice section; the free-response section is not broken down by unit.
Two rows are worth more of your week than the other seven. Unit 3 is the heaviest single unit at 18–22% of the multiple-choice section, and Unit 8 follows at 11–15%; everything else sits at 7–9%. One naming trap is worth knowing as well: Unit 6 is thermochemistry, so enthalpy, calorimetry and Hess’s law, while entropy and free energy belong to Unit 9. A chart that files thermodynamics under Unit 6 is still using the unit names College Board retired in 2024.
What College Board hands you on exam day
You are not expected to remember every constant. Two reference documents are provided, and for AP Chemistry they arrive on paper.
The periodic table and the equations sheet
The course and exam description carries both as appendixes. One is the periodic table of the elements. The other runs to a page of formulas and constants spanning atomic structure, gases and solutions, kinetics, equilibrium, thermochemistry and electrochemistry. Our AP Chemistry equation sheet page walks through what is on it, grouped by topic.
It is printed, and it stays in the room
AP Chemistry is one of nine subjects whose reference information is printed and mailed to schools rather than shown only on screen. The proctor hands it out with the rest of the testing materials. You may write on it, nothing you write there is scored, and you cannot take it out of the room at the break or after the exam.
A calculator is allowed on both sections
A scientific or graphing calculator is allowed on Section I and Section II, and College Board recommends one for both. Bluebook has a built-in Desmos calculator in scientific and graphing form, and you may also bring up to two approved handheld calculators without clearing their memories. AP Chemistry carries none of the 2027 handheld restrictions that apply to AP Biology, AP Environmental Science and AP Statistics.
What the chart cannot show you: how the points are split
The exam runs 3 hours 15 minutes and splits evenly. Section I gives you 90 minutes for 60 multiple-choice questions and carries half the score. Section II is 7 free-response questions in 105 minutes for the other half: three long questions at 10 points apiece and four short ones at 4, which puts the free-response section out of 46 raw points.
The part most cram charts leave out sits inside that second half. College Board publishes what each science practice is worth, and mathematical routines carries 43–53% of the free-response score, more than everything else combined. Argumentation is another 15–24%. Representing data and chemical phenomena with graphs and diagrams is worth 8–16% of the free response and is not assessed on the multiple choice at all, so drawing and graphing are free-response points or none.
Delivery is part digital and part paper. The multiple choice is answered in Bluebook, which is also where the free-response prompts appear on screen; the answers themselves go into a paper booklet in your own handwriting. The 2027 exam falls on Thursday, May 6, in Session 2, typically the afternoon slot.
AP Chemistry is also not graded on a curve. College Board calls the AP Exams criterion-referenced: your score turns on the standard you reach, not on how many classmates reached it. The 2025 results bear that out, with 168,833 test-takers, 77.9% earning at least a 3, and a mean of 3.36 sitting above the 3.24 all-subject figure. Our AP Chemistry difficulty guide sets that beside the other AP sciences.
Where students lose the most points
Most lost points on AP Chemistry are reasoning and bookkeeping errors, not gaps in the equations sheet. Graders want a claim backed by the chemistry and the data, so a number with no justification earns little, which is what that argumentation weighting is measuring. Watch your significant figures and units, label particulate diagrams clearly, and always show the setup. Our FRQ guide breaks down how each free-response question is scored.
How to use this in your last week
Read one unit of the cram chart, then do two or three free-response questions from that unit and grade yourself against the idea, the relationship and the mistake rather than against the final answer. Close the gaps with the AP Chemistry Progress Check walkthroughs, and check a practice raw score with the Chemistry AP score calculator to see where you stand. Used this way, these AP Chemistry review notes work as a checklist rather than a reading assignment: if you can state the idea, write the relationship and name the trap for all nine units, you have covered the framework.
Sources: the AP Chemistry Course and Exam Description (Effective Fall 2024), the AP Exams Calculator Policy, College Board’s reference information and exam-day policies for AP Exams, and the AP Students AP Chemistry exam and score-distribution pages.
Frequently asked questions
Quick answers, checked against College Board.
Can I bring a cheat sheet into the AP Chemistry exam?
No. College Board’s exam-day rules prohibit notes and reference guides, and a student found with one can be dismissed and have their score canceled. The proctor issues the only reference material allowed: a printed periodic table, plus a page of equations and constants.
What does College Board give you on the AP Chemistry exam?
Two documents: the periodic table, and the equations-and-constants sheet. For this subject they arrive as paper copies that the proctor distributes. You can write on them, anything you put there goes unscored, and they cannot leave the exam room.
Is a calculator allowed on the AP Chemistry exam?
Yes, on both sections. A scientific or graphing calculator is allowed and recommended, Bluebook has a built-in Desmos calculator, and you may bring up to two approved handheld calculators.
Which AP Chemistry units are weighted most heavily?
On the multiple-choice section, Unit 3 Properties of Substances and Mixtures is the heaviest at 18–22%, and Unit 8 Acids and Bases is next at 11–15%. The other seven units are each 7–9%.
Is AP Chemistry hard?
It scores better than its reputation. The 2025 results put 77.9% of test-takers at a 3 or above, with a mean of 3.36 where the all-subject figure was 3.24.