Using Visual BCA Tables to Teach Limiting Reactants

picture of materials and WS

A few months ago I was searching the internet, looking for a better way to teach stoichiometry to my pre-AP chemistry students. While my methods of dimensional analysis “got the job done” for most students, I would still always lose students and many lacked true understanding of what was happening in the reaction. I wanted to try something new that would promote a better chemical understanding. In my search for this elusive stoichiometry method, I came across Dena Leggett’s ChemEd X blog post entitled “Doc Save Everyone”, as well as other posts about BCA tables from Lauren Stewart, Lowell Thomson, and Larry Dukerich. 

You Are Invited: Chemistry Instruction for the Next Generation

Chemistry Instruction for the Next Generation graphic

ChemEd X and the Journal of Chemical Education (JCE) are collaborating to offer a virtual conference like most have never seen before. It is not a webinar. You do not have to schedule specific hours to view a live presentation. I think of it as similar to a virtual book/journal club with the added benefit of having the author leading it. In this case, authors were selected from among those who have published recent articles, activities and research in JCE on the topic of student-centered instruction in chemistry. The theme of this inaugural conference is Chemistry Instruction for the Next Generation.

Compiling Student Data

Excel file for compiling student data

To assist in grading the lab results for this and other quantitative labs that we did, I created Excel spreadsheets where the students’ results could be entered. The spreadsheet then did all the required calculations and compared the students’ results to the theoretical value. This made grading the lab reports much quicker and more accurate, flagged incorrect student calculations, allowed a much more complete discussion of the lab results and permitted “what if” questions to be discussed.

How do you meet your students where they are at?

How to Meet Students Where They Are At

I have had a variety of students with a broad range of academic abilities in my class at once. This hook doesn’t feel particularly deep until I stop and reflect for a moment on what that looks like.

Shorten Grading Time with this Stoichiometry Tool

Image of a chemistry themed clock

As many chemistry teachers know, grading lab reports can be a very time-consuming task. For me, the lab report that has required the most time to grade is a stoichiometry lab that I have been doing the past couple years. Though we do at least four “formal” lab reports each year, what makes this one different is that it involves a lot more calculations and subsequent results than any of our other labs. Regardless of how well they organized their report or wrote their conclusions, their results need to be checked for accuracy. This takes time. Even after eventually being able to generally eyeball their work, it still takes more time than I would like. So, this year I finally decided to sit down and generate a tool for me to expedite this process—the stoichiometry calculator.

Tracing the Steps to the Conant Award

Laura Slocum's award certificate

The James Bryant Conant Award was established in 1965 and has had several sponsors. The award is intended to recognize, encourage, and inspire outstanding teachers of high school chemistry. It is fitting that the Journal of Chemical Education and ChemEd X have established an endowment that will permanently fund the award. I think it is even more fitting that the 2017 Awardee, Laura Slocum, has a history with JCE as a precollege assistant editor from 2007 – 2011.

Group Tests?

The answer may be in the anecdotal evidence. The conversations between students were mini debates. “Are you sure this is correct?” “How do you know?” “What about this other data?” “Should we label that number?” “What about the energy of the particles during a phase change?” And on, and on, and on….They were having discussions between themselves that I would not have been able to elicit as a teacher.

Investigations of Chemicals in Natural Food Coloring. Part 3: Sunflower

Fluorescence of sunflower dye

The chemistry of the Sunflower dye found in McCormick’s Color from Nature food dyes is explored in this post. This is the last in a three-part series in which several experiments and demonstrations that can be done with Color from Nature food dyes are described.