ChemEd X articles address topics in chemical education ranging across the entire spectrum of the chemical sciences.
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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.
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.
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.
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).
In “How strong an acid is vinegar?” the students explore the nonlinear relationship between the concentration of a weak acid and the pH of the solution. This formative assessment targets the question “how does structure influence reactivity?” Students need to understand the behavior of strong and weak acids to comprehend phenomena like buffering capacity.
This formative assessment was designed to target students’ thinking around the structure-property relationships in an accessible, real-world context. This is done through targeting noncovalent interactions. The understanding of this topic is critical for students’ reasoning about observable properties of matter.
In the Frying Ice formative assessment students explore the three phases of matter. This formative assessment targets the question “What cues are used to differentiate matter types?” The target of this formative assessment was for students to demonstrate their understanding of the three states of matter and how the particles in each state react when heated.
The fire story formative assessment is used to explore students' thinking about the question "what affects chemical change?" through a real-world problem. This formative assessment specifically probes students' understanding of energy and phase changes. There are several different explanations using different chemistry concepts that could be used to explain the phemomenon explained in the story.
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.
Ice core science is truly cross-disciplinary as it draws extensively from chemistry, geophysics, geology, engineering, oceanography, microbiology, statistics, a deep understanding of historical events, atmospheric science, and climate science. And general chemistry topics include solubility, concentration, phase diagrams and changes, and stable isotopes in addition to many others. Let's take a first look at how ice core science can be used in teaching chemistry.