Looking to change up your titration lab? Citric acid is very common in candy and other foods. Students will be engaged in using titration to find the amount of the acid in Mentos Now or other candy. Student and teacher documents are provided to help you use the activity with your own students.
HS-PS1-7 Mathematical Representations
A solid grasp of proportional thinking is crucial to being able to solve all sorts of problems in chemistry as well as “real life” situations. While many students seem to intuitively understand that one mole is equal to 6.022 x 1023 particles when the analogy is drawn to a dozen eggs, for some, this sort of equality is a puzzling mystery.
A discussion of how students solve stoichiometry problems.
Inspired by Ben Meacham's post on stoichiometry, I looked to modify the lab sequence for my IB Chemistry class for our unit on stoichiometry. I will describe my experience modifying a typical empirical formula lab, along with using a modified version of the lab Ben shared.
The concept of the mole has always been a challenging topic for myself and my students. The challenge comes in part when we try to imagine 6.02 x 1023 of anything. Another challenge for some students is the math and theory behind this number and concept. I have tweaked an activity to help guide my students to an understanding of these concepts.
As I began to prepare my labs for this upcoming year, I decided to put a bit of a twist on a previous density of a block lab I had used in the past entitled the Measurement Challenge that is sold by Flinn Scientific. It can also be used to find the mass of a block given the materials density and requiring students to measure and calculate the blocks volume. My added twist resulted in great scientific discourse.
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.
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.
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”.