I love writing about chemistry, more than anything I’ve ever done professionally. In part that’s because I learn stupid stuff, an example of which occurred again yesterday. I was writing a larger piece about quinones and related compounds, and I got to thinking about gin. The only spirit I drink is gin. I’m really a beer guy, but I love a drop of mother’s ruin and tonic too. As you likely know, quinine is the essential ingredient of tonic water. Quinine can be isolated from the Cinchona tree, and because of quinine’s malaria fighting capabilities, the tree is known as the Fever Tree. And that ..read more

My 2023 AP Chemistry Free-Response DRAFT ANSWERS are linked at the bottom of this post. Please let the know where I have made errors and typos, and I will be happy to amend. Again, this is a staggeringly simple examination for what is supposed to be the gold standard in US, high school chemistry education. Of course, many children will struggle with it but that is absolutely not a function of the difficulty of the exam, but rather a continued function of the fact that thousands and thousands of kids that have absolutely no business taking AP Chemistry are still be placed in the course for nefa ..read more

In the Spring of 2023 I will once again be offering an Online AP Chemistry Review Course for AP Chemistry STUDENTS. The course will open on March 1st 2023. Let’s start with the basics Where? Online How? Via the Canvas LMS (Learning Management System). Typical screenshot shown below. When? The course will open on March 1st 2023. What? A comprehensive review of the Learning Objectives from the AP Chemistry Course, with guided reading from the AP Chemistry Crash Course book, example questions, hints and tips, a full mock exam with answers, and much more. Most of the modules involve some rea ..read more

AP Chemistry Online Summer Workshops 2023: Once again this coming summer I plan to offer two, AP Chemistry Teacher Workshops, and I’d love to have you join me. These courses will be the 19th and 20th respectively that I have offered online. Below you will find details of the workshops, but if after reading this post (and some of the anticipated FAQs), you have further questions, please do not hesitate to contact me. Thanks for taking the time to check this out, I hope to serve you this summer. Where? Online When? Each AP Chemistry Online Summer Workshop 2023 lasts for one week. The first is i ..read more

Here’s a little heads up on my best guesses for what will happen at the George R. Hague Memorial AP/IB Chemistry Symposium at BCCE 2022 on Monday, August 1st. Maybe I’ll be very wrong; maybe not, we’ll see. Inner Strength: Why do acids break up?. K.L. Hendren My guess is this a direct addressing of 8.6 in the CED. It’s no doubt routinely, poorly understood by students and indeed teachers, but there really is no mystery here. It boils down to electronegativity or resonance delocalizing the electron density around the anion, to make it less attractive to the dissociated H+, and therefore keeping ..read more

My short answer is, “yes”. Here’s more. This has been discussed a lot since 2019, and the general consensus seems to be that it is unlikely that a question would ask students to balance a REDOX equation in acid or base from scratch, but rather that they might only be asked to combine a couple of half-reactions with H+/OH– already present. However, there is absolutely no way on earth that I am going to remove this from my work with students for the following reasons. 1. There’s nothing in 4.9 that absolutely rules out the possibility of an acid/base REDOX situ ..read more

Honestly, the likelihood is that you’re doing just that! Wasting precious time on a concept that the kids will mostly never be able to understand, and moreover one that’s of virtually no practical use to them. Huge amounts of time and handwringing are spent on attempting to get chemistry students to grasp the concept of the mole, or perhaps more accurately, to grasp the concept of Avogadro’s number. One of the things that chemistry teachers often say at the beginning of this topic is that, “Avogadro’s number is so large that it’s impossible for you to even imagine a number that big”. And ..read more

AP Chemistry Online Winter Workshop 2022: I plan to offer a one-day, AP Chemistry Teacher Winter Workshop in December of 2022 and I’d love to have you join me. Sign up using this form at the bottom of this page. Below you will find details of the workshop, but if after reading this post (and some of the anticipated FAQs), you have further questions, please do not hesitate to contact me. Thanks for taking the time to check this out, I hope to serve you in December. Where? Online. When? On a date to be decided upon (I’ll be surveying participants), but sometime between Monday 26th and Friday 30t ..read more

Just over a week ago I attended the George R. Hague Memorial AP/IB Chemistry Symposium at BCCE 2022 (quite what IB has got to do with anything that was presented I have no idea). The purpose of the symposium is essentially three-fold. To give a platform to the College Board to pimp their propaganda (Jamie Benigna’s job); to allow the CB shills to speak for short periods (15-20 mins) on AP chemistry topics of their choice; for the Chief Reader new in 2022) to break down the May 2022 exam. The first two have little or no interest for me, but the latter is always worth listening to. Having s ..read more

Routinely, buffers are cited by AP chemistry teachers as the topic that their students find the most challenging. Not necessarily equilibrium, but buffers. So, what about essentially largely avoiding the teaching of buffers completely, and approaching the problem from an equilibrium viewpoint instead? Let’s consider an example calculation. 20.0 mL of 0.100 M ethanoic acid (Ka = 1.80 x 10-5) is titrated with 6.00 mL of 0.100 M NaOH. Calculate the pH of the resulting solution. Method 1, treat it like the buffer solution that it is by using the Henderson-Hasselbalch equation To most teachers this ..read more