Titration of an Esterification Reaction to Determine Equilibrium Constant

ChemEd X recently made a Call for Contributions soliciting input regarding the big ideas being put forth by organizations like AP. The first thing that came to mind was a lab I modified that is centered around making connections between topics. Admittedly, this lab is not a "big idea" per se. Rather, it's the big idea that students should be able to make connections between topics we study to solve problems. So in this blog post, I would like to share a lab activity that relies on these connections - between stoichiometry, esterification, equilibrium, kinetics, titrations and uncertainty of calculations. I will also share the resources I have created to support my students through the process of working through these calculations.

Time required: 

Three class periods

Day 1: setup of equilibrium mixture; roughly 30 minutes

Day 2: titration of equilibrium mixture (approximately 1 week after Day 1); roughly 60 minutes

Day 3: calculations; variable time required - typically 30-90 minutes depending on the student group

Doc Saves Everyone – Applying BCA Tables to Titration Calculations

doc saves everyone

I recently stumbled across a blog about the use of BCA (Before Change After) tables for stoichiometry written by Lowell Thomson.  I was thrilled to discover ChemEd Xchange!  I wanted to share my journey, spurred on by my students, into the extensive use of the BCA approach in AP and IB chemistry.  I hav

One teacher's attempt to use BCA Tables for Stoichiometry

The thermal decomposition of copper II carbonate basic

In this blog post I'll describe a recent attempt at using BCA Tables for teaching stoichiometry. I discuss the method I used with one introductory chemistry class to teach both the algorithm method and BCA tables to learn more about a technique I've been curious about for a while.

Target labs, Reviews and THAT kid...

It is really hard to get to know THAT kid especially when I have classes of other kids who are important and have needs also. Stack on top of this teenage hormones, spring, nice weather, prom, AP tests, state testing and trying to sell as hard as I can how fun "stoichiometry" is....I now run the risk of turning a bunch of other kids into THAT kid pretty quickly.

Spring Fever, Stoichiometry and Specific Heat


From the looks of things, we are all in the same boat. Spring fever. I had two groups of students. Both are ending 3rd quarter, looking out a window at the first nice weather we have had in weeks. Most are already planning their spring break vacation and some have left early. Notice, not much talk about chemistry. The curriculum said it was time for stoichiometry for one group and specific heat for another. Just what the kids wanted to do (read with sarcasm).

What is it a student should be able to do and explain? How do we find that out???

mole activity

A perfect storm starts to form. We are on the concept of moles and I have some students who are struggling mathematically. It is a rough time of year to get kids excited. Many students are struggling with ACT and SAT prep and as a teacher, I am tired of test...test...test. Also, I had about two dozen 2 liter bottle "pre forms" that I needed to find something to do with.

Rethinking Stoichiometry

BCA table

Stoichiometry is arguably one of the most difficult concepts for students to grasp in a general chemistry class. Stoichiometry requires students to synthesize their knowledge of moles, balanced equations and proportional reasoning to describe a process that is too small to see. Many times teachers default to an algorithmic approach to solving stoichiometry problems, which may prevent students from gaining a full conceptual understanding of the reaction they are describing. 

Going from Cookbook to Inquiry...Messy but worth it.

Results from lab of Iron and copper(II) chloride.

We, as teachers, can see that life is sometimes like this and we care enough about our students that we want to try to prepare them for careers and problems that we can’t even imagine….because we believe that good education can empower people to go further and reach higher than they could ever dream….and maybe the journey we will  start together begins with a simple question in which the answer may not seem immediately obvious...and that is O.K….