AP Chemistry Labs

In the AP® Chemistry course, labs play an important role and understanding experimental procedures is essential for the final exam. AP Chem Labs account for 25% of class time¹, making them an important element of the curriculum. Throughout the year, you will be expected to do at least sixteen hands-on lab experiments, six of which must be "guided inquiry" labs. According to the College Board® course description, "Increased lab time is linked to greater AP results."

This page contains all of the required information for the AP Chemistry Labs, including the requisite materials and a list of the labs.

Why Are AP Chemistry Labs Important?

AP Chemistry labs are crucial for understanding chemical concepts and supporting scientific evidence. The College Board mandates that AP Chemistry teachers allocate at least 25% of instructional time to lab investigations. These inquiry-based labs, outlined in the AP Chemistry lab manual, provide students with practice in designing experiments, collecting and analyzing data, and refining scientific explanations. With 16 inquiry-based labs² available, students gain valuable hands-on experience in "doing science." This practical approach is integral for preparing students for the AP Chemistry exam, which evaluates both their science practice skills and content knowledge development.

AP Chemistry Lab Materials

The equipment and materials required for AP Chemistry lab investigations are generally similar to those used in typical high school-level chemistry courses. However, access to some specialized equipment (e.g., pH meters, spectrophotometers, etc.) may be needed to carry out certain investigations. For each lab investigation, most lab manuals provide a list of materials and equipment required.

What labs are in AP Chemistry?

The current AP Chemistry lab manual features 16 inquiry-based lab investigations, aligned with the curriculum framework. While there used to be 22 labs, the focus has shifted to these 16 labs. Teachers have the flexibility to substitute other inquiry-based labs covering content within the curriculum framework.

The list of AP Chemistry labs consists of the following 16 labs from the lab manual³:

Investigation 1: Spectroscopy

In this lab, students explore the relationship between different regions of the electromagnetic spectrum and the types of transitions (molecular and electronic) that are associated with different regions of the spectrum. Students will gain experience reading a UV-VIS spectrum, applying graphical information, and designing experimental procedures.

Investigation 2: Spectrophotometry

This lab investigation allows students to explain the relationship between the amount of light absorbed by a solution and the concentration of that solution. Students will get to practice using a spectrophotometer, identifying wavelengths and determining the molarity of a specific solution. Students will also use computational skills to identify the percent by mass composition of an element in a solution.

Investigation 3: Gravimetric Analysis

Here, students will demonstrate their knowledge of quantity calculation using the mole concept and dimensional analysis skills. They will analyze the relationship between the composition of elements by mass and a pure substance’s empirical formula. Skills used in this lab include determining the relationship between microscopic and macroscopic behaviors of a solution and developing experimental protocols. Students also explore theoretical yield and the process of filtration.

Investigation 4: Titration

In this lab, students gain experience identifying the equivalence point in a titration. They will design a data collection procedure, including selecting appropriate lab equipment and an acid-base indicator, representing their results with diagrams, and making predictions about a real-world application of the experiment.

Investigation 5: Chromatography

This investigation allows students to dive into the relationship between the solubility of compounds in different solvents and intermolecular forces. Students will practice the skills of improving experimental results, collecting data, evaluating a paper chromatograph, and making scientific claims. They will also create models to represent the attraction between molecules.

Investigation 6: Bonding in Solids

In this experiment, students explore the relationship between the type of bonding that occurs between elements and the properties of those elements. Students will dive into the relationship between a substance's macroscopic properties, the microscopic structure of that substance, and particle interactions. They will practice designing an experiment, creating particulate models of bonds, analyzing data, and making scientific claims. Students will also design a flowchart applying what has been learned in the experiment to identify unknown solid compounds.

Investigation 7: Stoichiometry

In this lab, students learn to perform calculations on solutions, including volume, molarity, and the number of solute particles. Additionally, students will use a balanced reaction equation to explain changes in the amount of reactants and products. During this investigation, students will mimic activities in the peer-review process of science, including verification of an experiment that has been performed, checking calculations, and analyzing experimental findings.

Investigation 8: Oxidation-Reduction (Redox) Titration

Students will learn how to represent changes in matter with a balanced equation (chemical and net ionic) while conducting a redox titration. Students will perform calculations to determine the concentration of an unknown solution. They will also get to critically analyze the design of an experiment to find ways to improve upon it.

Investigation 9: Physical and Chemical Changes

In this investigation, students explore how to identify the pH of a buffer solution by using the concentrations and identities of the conjugate acid-base pair that was used to make the buffer solution. Students will gain practice designing a flowchart for the experiment, inferring whether physical or chemical changes have taken place, and improving experimental design. They will also learn the basics of vacuum filtration and how to perform acid-base separation.

Investigation 10: Kinetics: Rate of Reaction

Here, students will explore the relationship between the specific parameters of an experiment and the rate of a certain chemical reaction. In this experiment, students will form a hypothesis, make modifications to an experimental procedure, and gain practice graphing data and drawing conclusions from data. Finally, students will practice sound laboratory skills such as accurately timing the occurrence of reactions.

Investigation 11: Kinetics: Rate Laws

During this experiment, students will relate experimental data to a rate law expression and practice identifying the rate law of a particular chemical reaction. Students will apply equations (e.g., Beer’s law) to calculate rate laws. Graphing skills are used in this investigation, including how to perform linear regression.

Investigation 12: Calorimetry

Students will practice calculating the heat absorbed or released by a particular system that is undergoing heating, cooling, a phase change, or a chemical reaction. In doing so, they will be able to explain a model in terms of chemical theories, evaluate data, and perform calculations to determine the heat of the reaction. Students will also gain an understanding of experimental errors and practice analyzing graphical data.

Investigation 13: Equilibrium

In this investigation, students will use Le Châtelier's principle to determine the response of a system at equilibrium due to a perturbation and identify perturbations that can cause a change a given system. They will be able to predict the direction in which a reaction will proceed in order to reach its equilibrium. Students will gain further understanding of how to design and execute an experiment, as well as how to interpret data.

Investigation 14: Acid-Base Titration

Students will learn how to perform acid-base titrations and explain the results of the titration in relation to the solution's properties and components. In doing so, students will practice drawing models to represent the different protonation states of a titrant during a titration. Furthermore, students will gain practice with calculations of values, including pH and pK_a, choosing a testable question, analyzing titration curves, and collecting and comparing data.

Investigation 15: Buffering Activity

Here, students will investigate buffer solutions and how they stabilize pH. Students will practice experimental design, accurate observation and collection of data, and graphical representation of obtained data. Students will also become familiar with estimating equivalence points and whether an unknown solution can act as a buffer.

Investigation 16: Buffer Design

In this final investigation, students learn how to prepare an effective buffer and how to test its buffering capacity. They will relate this information to the relative concentrations of the conjugate acid and conjugate base of a solution. Given a question from the instructor, students will design an experiment to test that question and brainstorm ways to improve their design.

You finally know why labs are an essential part of AP Chemistry. The more experience you have doing labs aligned with the AP Chemistry curriculum framework, the better prepared you will be for the AP Chemistry exam. To get a comprehensive plan with everything you need to know about the AP Chemistry exam, check out our guide on AP Chemistry units and how to study for AP Chemistry. With these resources at your disposal, you have everything you need to reach your goals in AP Chemistry!

References

¹(2020). Course Overview. Advanced Placement Chemistry Sample Syllabus #1. College Board. Retrieved on March 01, 2024 from https://apcentral.collegeboard.org/media/pdf/ap-chemistry-sample-syllabus-1.pdf
²(2024). The Lab Manual. AP Chemistry Lab Manual. College Board. Retrieved on March 01, 2024 from https://apcentral.collegeboard.org/courses/ap-chemistry/classroom-resources/lab-manual
³(2022). Lab Time. AP Chemistry Course and Exam Description. College Board. Retrieved on March 01, 2024 from https://apcentral.collegeboard.org/media/pdf/ap-chemistry-course-and-exam-description.pdf