The 2026 AP Chemistry Exam scores: 5: 15%; 4: 31%; 3: 30%; 2: 18%; 1: 6% In 2026, ~185,000 AP students took the AP Chemistry Exam — roughly 1% of the U.S. high school population. AP Chemistry Multiple-Choice Questions (MCQ) • Students performed especially well on questions covering Unit 1: Atomic Structure and Properties (70% of students earned most of the points available on such questions), Unit 4: Chemical Reactions (74% of students earned most of these points), and Unit 9: Thermodynamics and Electrochemistry (72% earned most of these points). • The most challenging MCQ content area was Unit 7: Equilibrium, a unit that requires students to write equilibrium expressions, calculate equilibrium quantities, predict shifts using Le Chatelier's Principle, and relate Ksp to ion concentrations in solubility problems. 34% of students answered most of these questions correctly. Almost as challenging were the questions related to Unit 6: Thermochemistry; 49% of students got most of these right. AP Chemistry Free-Response Questions (FRQ) Each AP exam has multiple versions, for different time zones. I'll focus the commentary below on the version taken by most students: apcentral.collegeboard.org/m… Since AP scores are reported on a 5-point scale, the free-response questions deliberately include some very difficult points, designed to differentiate AP 5s from AP 4s, points of varying difficulty to differentiate AP 4s, 3s, and 2s, and more foundational points to separate AP 2s from AP 1s. FRQ #1, the KCl Calorimetry and Solubility question (10 points), is a multi-part investigation anchored in dissolution thermochemistry, and it was the most difficult of the long questions on this year’s exam, serving to differentiate among exams scoring AP 3s, 4s, and 5s, as students receiving AP 1s and 2s were generally unable to earn many of these points. The breadth of knowledge and skills demanded here, from conceptual reasoning about atomic structure to multi-step calorimetric calculations to qualitative equilibrium analysis, is a great representation of rigorous, college-level lab chemistry. • Part B (describing how to identify when dissolution ends) was a key differentiator between AP 3s and AP 2s, as AP 3s were consistently able to earn this point, whereas AP 2s were not. • Part D (applying error analysis to justify a directional claim about the calculated enthalpy) was the most challenging part of this question, typically achieved only by students receiving AP 5s. FRQ #2, the Chromium Species question (10 points), asked students to work through various concepts, from Lewis structures to electrochemical stoichiometry using Faraday's laws, and first-order reaction kinetics. The final part required students to draw a natural log of concentration versus time graph to demonstrate their understanding of how changing reactant concentration shifts a kinetics curve. Almost as challenging as FRQ 1, this question also served to differentiate among students scoring AP 3s, 4s, and 5s, as students receiving scores of AP 1s and 2s were generally unable to earn many of these points. • Part E (using data specifically from the concentration versus time graph to support that the reaction is first order) was the most challenging point on Q2, and it differentiated between students receiving an AP 5 and those earning an AP 4, who were not usually able to earn this point. • Part B(i) (writing a balanced net ionic equation for the reaction between chromate and a strong acid) was almost as challenging, also often making the difference between whether a student received a 4 or a 5. FRQ #3, the Nitrous Acid question (10 points), was somewhat less challenging than the two other long questions, serving also to differentiate between scores of AP 2 and 3. Across this FRQ, students were asked to demonstrate a range of college-level chemistry knowledge and skills, from identifying conjugate acid-base pairs to calculating various weak acid equilibrium quantities to analyzing the results of a titration experiment. • Part D (using the titration curve to determine the pH at the equivalence point) was an important distinguishing point for students earning AP 3s, requiring a fundamental understanding of the stoichiometric endpoint; students receiving AP 2s were not typically able to earn this point. • Part G (calculating the K value for the neutralization reaction) was the most difficult point on this question, usually only earned by students achieving AP 4s and 5s. FRQ #4, the P4 and P2 Equilibrium question, spans molecular structure reasoning all the way to thermodynamic argumentation — in just four points. • The second point of Part B (calculating Kp from partial pressures) was earned by most students, but was not typically attained by students receiving 1s and 2s. • Part C (justifying whether the reaction was endothermic based on thermodynamic principles) was the most challenging part of this question, typically performed accurately by students receiving 4s and 5s. FRQ #5, the CBrClF2 Molecular Structure question (4 points) was challenging, distinguishing between scores of AP 4 and 5, as students receiving other scores were not usually able to earn many of these points. This question weaves together VSEPR theory, electronegativity, and intermolecular force reasoning — three important and interconnected concepts in first-semester college chemistry. • Part B (explaining bond angle differences via electron cloud size and repulsion) was the most challenging point, generally only earned by the students receiving AP 5s. FRQ #6, the Vanadium(II) Spectrophotometry question (4 points), was a moderately challenging question, and helped to distinguish among students within the score range of AP 3, 4, and 5, as students with lower scores generally could not engage with this level of difficulty. This question was anchored in an authentic laboratory context: students had to draw a particle diagram to represent the dilution of a V2+ solution; apply Beer's Law to calculate molar absorptivity from a standard curve; use molar absorptivity to find the concentration of an unknown solution; and assess the effect of a volumetric error on the calculated molarity — correctly determining the direction of the error and supporting the claim with a valid justification. • Part A (drawing a particle model consistent with dilution by a factor of 2) is an effective differentiator between students achieving AP scores of 2, which could not earn this point, and scores of 3, which could. FRQ #7, the Na2O Enthalpy question (4 points), was another challenging one. Students had to apply Hess's Law to calculate ΔH°; identify the limiting reactant from reactant masses; calculate the energy released from that amount of limiting reactant; and explain why Na2O has weaker lattice energy than Rb2O by connecting the separation between ions to Coulombic force. • Part C (requiring students to invoke the relationship between ionic separation and lattice energy using Coulomb's law reasoning) was earned by 17% of students, typically only achieved by students receiving an AP 5. All subjects' AP score distributions for 2026 will be posted here when available: apstudents.org/score-distrib…

The 2025 AP Chemistry Exam scores: 5: 17%; 4: 29%; 3: 32%; 2: 16%; 1: 6% As a reminder, these data only include the results of the AP Chemistry exam taken on the standard testing date, Tuesday, May 6. Multiple-Choice Questions This year, the mean number of correct MCQs was 36.99, compared to 35.00 last year, and 33.65 in 2023. On the make-up date this year, for which I have the multiple-choice data (but not yet the free-response data), the mean number of correct MCQs was 35.82. Equating data, which looks at each group’s performance on re-used MCQs, also confirms that this year’s group, on average, was stronger than prior years’ groups, demonstrating stronger chemistry content knowledge and skills, so scores increased. Setting aside Atomic Structure and Properties (Unit 1), which a massive 34% of AP Chemistry students aced by answering every such question right, students demonstrated strongest mastery of Thermochemistry (Unit 6); 18% earned every point possible for that unit. By far the most challenging unit for AP Chemistry students was Acids and Bases (Unit 8); 7% of students earned every point possible for this unit, and 6% of students, generally those who are receiving 1s, were unable to answer any question about this unit correctly. So this is a good unit for further focus as next year’s AP Chemistry students and teachers seek to extend AP Chem’s super impressive, multi-year trend of stronger content and skill mastery. Another rave for the AP Chemistry community: they have pulled off this year’s significant increase in student performance while also expanding this very challenging course to 18,000 more students, overtaking AP Economics to be the subject that has provided the most additional students with access to the learning environments of their classrooms. I hear and share concerns of school administrators rushing AP Chemistry teachers by cutting labs or not providing adequate instructional time, so there are certainly exceptions to the positive trend in performance over time, but it’s good to see that in aggregate, performance is improving alongside increased opportunities. Free-Response Questions spr.ly/60164TpAM Question 7, the Glycolate question, is psychometrically pristine, the most statistically “perfect” question I’ve yet seen on this year’s exams, which means that each of the 4 points is significantly different in difficulty from every other point, so that the measurement value of the question is high, working well to differentiate between students who should receive 5s, 4s, and 3s. Students who can answer every part of this question are typically receiving an AP 5 for their overall work on the exam; students who can answer all but one part of the question are generally receiving an AP 4; and students who can answer 1-2 parts of the question are generally receiving AP 3s. Students unable to answer any part of this question correctly are typically receiving AP 1s and 2s. The highest performance on this year’s free-response questions was on Q4, the Methanol and Formaldehyde question. 22% of students earned all 4 points on it. The most challenging of all this year’s AP Chemistry free-response questions was Q6, the Zn and AI Galvanic Cell question, which identified the most advanced students in the course, generally helping to identify which would receive AP 4s and which would receive AP 5s. 5% of students earned all 4 points on it. All subjects’ AP score distributions for 2025 will be posted here when available: spr.ly/60174TpA3