first-year undergraduate

Resources for Teaching Online in 2020

As we continue to make plans to teach during these uncertain times we have been compiling a list of both new and previously published ChemEd X posts and resources that will be useful to readers while teaching during the COVID-19 pandemic. Do you have an activity, strategy or idea to share with the community? Is there a resource you would recommend? We welcome contributions. This list will grow, so check in again to see what has been added. 

An Upcycled Teaching Aid for Ionic Formulas

Determining the empirical formulas of ionic compounds based on charge balance is often a challenge for beginning chemistry students. Many visual aides have been developed for this purpose, from repurposing commercial interlocking bricks to custom 3-D printed bricks. This article describes yet another option– upcycled can carriers.

Aqueous red cabbage extracts: More than just a pH indicator

The use of anthocyanins in red cabbage extracts as pH indicators has long been a popular classroom activity. Flowers, fruits and vegetables contain a diverse range of anthocyanins. This investigation explores further applications of plant-derived dyes including reversible reactions based on oxidation/reduction chemistry and other reactions to illustrate colour changes that are not solely dependent on pH change. By using household materials and plant dyes, this investigation may potentially be completed at home if necessary.

Color Changing Coke and Mentos

What's a better way to start the new school year than with some new experiments? Learn how to use a variety of color changing experiments to teach students about the Diet Coke and Mentos experiment, acids, bases, chemical and physical changes, and climate change.

Ice Cores, Stable Isotopes, Climate Change, and Chemistry: Part 2

Two important types of information obtained from ice cores comes from the bubbles in the glacial ice and the stable oxygen and hydrogen isotopes within the frozen water molecules themselves. This post describes how the bubbles (air pocket 'fossils') and stable isotopes are used to determine the concentration of gases in the ancient atmosphere, particularly in relation to past temperatures.

Comparing household chemicals

In "Comparing household chemicals" students discover the effects of using different types of household chemicals and determine if they are really all so different. This formative assessment targets the question “What are the effects of using and producing different matter types?” This is important because students should understand the types of products they are using. If they are buying something that says it is a cleaner for the bathroom, why does it sometimes have the same compounds in it as a cleaner for the kitchen. If students can recognize this, then they can be better consumers and not have to buy two different products knowing that the chemicals are the same.

Airbag challenge

In the “Airbag challenge” the students are tasked with developing a safe airbag for a car company. This formative assessment explores students’ thinking about the question “How can chemical changes be controlled?” The central concept in this challenge is the application is stoichiometry. Students are expected to use the numbers of moles of reactant consumed or product formed in a balanced chemical equation and to determine the change in the number of moles of any other reactant and product. Students need to use molar mass to convert mass of a reactant or product to moles for use in stoichiometric calculations or to convert moles from stoichiometric calculations to mass. Students use the ideal gas law equation to determine the numbers of moles in a sample of gas not at standard conditions.

Salt vs. Sugar – A Dissolving Problem

This formative assessment looks at two household chemicals (table salt and sugar) and compares their properties while looking at how they dissolve in water. The “Salt vs. Sugar” formative assessment explores students’ thinking about the question “How does structure influence reactivity?” The main idea that is being targeted is for students to think about what is happening at the molecular level during the solution process. This activity is important for students because it helps create a context for what some of the vocabulary and concepts mean by providing tangible examples of these concepts (such as the concept of saturation).This formative assessment looks at two household chemicals (table salt and sugar) and compares their properties while looking at how they dissolve in water. The “Salt vs. Sugar” formative assessment explores students’ thinking about the question “How does structure influence reactivity?” The main idea that is being targeted is for students to think about what is happening at the molecular level during the solution process. This activity is important for students because it helps create a context for what some of the vocabulary and concepts mean by providing tangible examples of these concepts (such as the concept of saturation).