Surviving and Thriving in the AP* Chemistry Curriculum, Part 1
Chemistry Teacher and Author
If you're reading this, you're probably an AP Chemistry teacher who has survived 1 semester of the curriculum. Congratulations! Perhaps you had a to-do list in August that looked something like this:
- Incorporate 6 inquiry labs into the AP Chemistry course
- Submit an updated syllabus for the audit
- Learn about PES
OK, so some things may not have gone entirely smoothly, but how can you ease your burden going forward? Well hopefully, in addition to knowing the content that is still ahead, you're also aware of the content that isn't in your future. There are 22 exclusion statements that appear in the course and exam description that are designed to tell you what's "out".
Here's a handy-dandy quick guide to the stuff you can omit. These exclusion statements are found in the appropriate Essential Knowledge sections of the AP Chemistry Course and Exam Description, available for download at http://advancesinap.collegeboard.org/math-and-science/chemistry, which also includes a Rationale statement for each exclusion. Note: These comments are my own interpretations and come with the disclaimer that they could significantly change over time, when more exam questions and knowledge about the course come to light.
Exclusions quick guide
- Memorization of exceptions to the Aufbau principle. This article, "The trouble with the Aufbau principle," might shed some light on these exceptions.
- Assignment of quantum numbers. Electronic configuration is still "in," so you'll still be teaching the principal quantum number.
- Phase diagrams, colligative properties and calculations of molality, percent by mass, and percent by volume. Molality goes to the grave with colligative properties, but it's difficult to have discussions about empirical formula (and impossible when dealing with the real-world inquiry H2O2 / MnO4- titration that is Investigation 8), without talking about percent by mass!
- Other cases of weaker hydrogen bonding (i.e., those outside of H connected to N, O, or F). There's no change here (i.e., hydrogen bonding is still "in") and this statement has only been included because of the recent redefinition.
- Knowledge of specific types of crystal structures and the study of the specific varieties of crystal lattices for ionic compounds. Crystal structures have never been on a contemporary AP exam.
- The use of formal charge to explain why certain molecules do not obey the octet rule. Don't misinterpret this—formal charge is still "in" and could be used to distinguish between 2 structures that do obey the octet rule, but it will not be used to explain why a Lewis structure with an expanded octet might be preferred over an alternative one with just an octet.
- Learning how to defend Lewis models based upon assumptions about the limitations of the models. Since it is linked to EK:2C4f and EK:2C4d, for now I interpret this to mean that formal charge is not going to be used to justify a Lewis structure with odd numbers of electrons.
- An understanding of the derivation and depiction of hybrid orbitals. Who has been teaching "derivation and depiction" of hybrid orbitals, anyway? Speaking of hybridization, sp, sp2, and sp3 are still "in," but any involvement of d-orbitals in hybridization is "out."
- Other aspects of molecular orbital theory, such as recall or filling of molecular orbital diagrams. I have never taught any MO since it has been "out" for years; however, EK:2C2i suggests that maybe the interpretation of an MO diagram could be "in." This is an interesting development and worth keeping an eye on, although remember, every question must be associated with a specific Learning Objective and it's tricky to find one that would fit.
- Lewis acid-base concepts and language of reducing and oxidizing agents. Say what? Any kid leaving an AP course that I have taught will know what Lewis acids and bases are, and they will be using the terms "oxidizing" and "reducing agent."
- Labeling electrodes as positive or negative. The assignment of charge to electrodes in electrolysis and cells is confusing, and doesn't add much to understanding the electrochemistry itself.
- Nernst equation. Careful, because although quantitative stuff about non-standard conditions in cells has gone, qualitative reasoning is still in play; you'll need to apply Le Châtelier's principle to non-standard cells and maybe even deal with a concentration cell.
- Calculations involving the Arrhenius equation. As an exclusion, this means little since calculations have rarely ever been features of contemporary exams, but expect the useful application of the equation in a y = mx + b plot to determine the activation energy and qualitative aspects to remain "in."
- Collection of data pertaining to the experimental detection of a reaction intermediate. Precisely who has been "collecting data" about intermediates to build evidence in support of one mechanism over another as an exam skill?
- Numerical computation of the concentration of each species in the titration curve for polyprotic acids. Still expect calculations for monoprotic acids and qualitative treatments of polyprotics.
- Computing the change in pH resulting from the addition of an acid or base to a buffer. Buffer calculations are still "in" (Henderson-Hasselbalch remains among the Equations and Constants), so I interpret this to mean that a question where addition of acid or base to buffer that is formed outside the context of a titration is "out."
- The production of the Henderson-Hasselbalch equation by the algebraic manipulation of the relevant equilibrium constant expression. The equation was (and still is) given with the exam; the derivation of the equation is "out."
- Memorization of other "solubility rules." A pity since some rote learning is good; competent chemists do not need to google basic facts!
- Computations of solubility as a function of pH and computations of solubility in such solutions. These 2 statements seem to be saying that quantitative, common ion calculations that involve H+ and/or OH– are "out," as are calculations relating to EK:6C3f. I think that one could also interpret them to mean that all, quantitative common ion treatments are "out" but like so much of what is written above, only time will tell!
Count on Carolina's support
As you soldier on through this year of the AP Chemistry redesign, remember that Carolina has a full line of AP Chemistry kits, Carolina Investigations® for AP Chemistry, specifically designed for the AP Chemistry curriculum. The 16 kits in this series address the 6 Big Ideas of chemistry and meet the requirements of the lab curriculum. Each kit focuses on a single Big Idea and offers the option to do either a guided activity or an inquiry activity with your students. To help students prepare for the AP Chemistry Exam, all kits include Big Idea assessment questions that follow the AP Chemistry Exam's free-response format.
Flexibility to teach AP Chemistry YOUR way
The College Board's AP Chemistry lab manual contains 16 inquiry labs that teachers can choose from to fulfill the requirement of 6 inquiry labs in the AP Chemistry course. The materials and quantities needed for these example labs are listed in the document "Materials for AP Chemistry Guided-Inquiry Experiments: Applying the Science Practices". Also included in this document are suggestions for the corresponding Carolina Investigations® for AP Chemistry kits that meet the same Learning Objectives as the College Board example labs.
*AP is a registered trademark of the College Board, which was not involved in the production of, and does not endorse, these products.