# New AACT Resources to Help Teach Stoichiometry

By Kim Duncan on December 5, 2019

As chemistry teachers around the country plan activities for their students, AACT will highlight resources from our high school resource library that can be used to reinforce topics in different units throughout the school year. Our last post highlighted resources to support a unit on Chemical Equations. We will now focus on new resources to use in a Stoichiometry unit plan.

If you have students who struggle with the concept of Stoichiometry, A Stoichiometry Puzzle is a great activity to help them. It provides students with a tactile method that will help them develop a better understanding of how to set up a stoichiometry problem using dimensional analysis. Cutouts that include conversion factors, along with an answer key, are included with this resource.

The activity, Farfalle Stoichiometry is a great way to introduce the topic of a limiting reactant. Students use hands-on manipulatives (pasta) to represent the stoichiometric relationships in a compound and in a balanced equation. They then determine the limiting reactant for a given amount of two reactants and identify the excess reactant. In the extension exercise, students will balance the equations that are used in the production of ammonia, a common chemical fertilizer.

Use the simulation, Chemical Reactions and Stoichiometry to give your students extra practice on the topics of reaction types, balancing equations, and stoichiometry calculations. The simulation is set up as a short quiz that includes five types of chemical reaction that students have to identify and balance. They are then asked to complete one of the following types of stoichiometry problems: mole-mole, mass-mole, mole-mass, mass-mass, mole-molecule, atoms-mass, or molecule-mass.

The lab, Analyzing the Reaction Between Baking Soda and Citric Acid is a great culminating activity for a Stoichiometry unit. Students examine the reaction between citric acid and baking soda and then analyze the chemical equation, balance it, and calculate needed quantities of each reactant for a complete reaction. Based on their observations, students determine if all reactants were completely used during the reaction.

We hope that these activities can help you to reinforce several of the topics covered in a unit about Stoichiometry. Most of these lessons were made possible by great teachers who shared their own resources. We need your help to keep the collection growing. Do you have a great demonstration, activity, or lesson related to this topic that you would like to share with the community? Please send it along for consideration.