If you are looking for a measuring and density activity that will be challenging, allow students to experience success early on and can be boxed up to use again, you might consider trying the activity that I am sharing in this post.
In a recent post, I shared sample quiz questions as to how I have differentiated assessment within the mole unit. Here, I share a specific multi-day sequence within the stoichiometry unit. I have written extensively about the project that drives this unit (within the following blog posts: Why consider trying project based learning?, Backwards planning your PBL unit - An Overview of an Entire Unit and What ARE my students actually learning during this long term project (PBL)?), but very little about specific learning tasks. Below is a two day sequence of stoichiometry practice that I set up in my classroom. Stations are set up around the room and students rotate as necessary.
Looking for a better way to teach stoichiometry? Melissa incorporates modeling into BCA tables.
I am a very firm believer that the world of physical science can be visualized and is an excellent medium for teaching students to model and to picture what happens at the molecular level. The first topic we decided to explore was balancing chemical equations. This seems like such a simple topic to chemistry teachers but I have found that it can be quite challenging for many of my inner city students. The first thing they ask me for is a list of rules that they can follow. We can discuss the problems of algorithmic teaching in a later post! For the time being let’s talk about how to get students to understand why they need to balance equations and discuss what we can call “Conservation of Atoms”.
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.
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.
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.
There is a traditional stoichiometry lab I have done before. It involves adding dilute hydrochloric acid to sodium bicarbonate, boiling off the fluid and then getting the mass of the sodium chloride. Students then can solve the percent yield for the sodium chloride based on the amount of sodium bicarbonate they use. It is not a bad lab. Something about having hot ceramic watch glasses with acid just makes me a bit nervous. I am not sure where I got this new lab, but it has been one that has evolved over the years It is quick, dirty, relatively simple and uses over the counter (mostly) materials.
Are students reflecting on what their calculated values indicate? This question constantly runs through the minds of chemistry teachers across the country. Recently educators have seen shifts in instruction that promote connections to real-world phenomena using conceptual depth in understanding.
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….
