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The ACS Exams Institute is pleased to announce that new tutorial practice exams are now available for General Chemistry, (first term) and Organic Chemistry (full year).
Michael Morgan shares a lesson that he has used for many years that not only requires students to explain a topic that they have not been directly taught but also to develop explanations based on previous knowledge. He has used this lesson as a multiday “in-class” assignment and also as an “at-home” independent study. It works well in both scenarios with only minor revision. The lesson is based on Alfred Werner’s work on deducing the structures of coordination compounds.
The November 2020 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: microplastic contamination and the environment; diversity, equity, inclusion, and respect in chemistry education research and practice; teaching in the time of COVID-19; chemistry and health; service learning; using games to teach; examining structures; solubility; spectroscopy; natural products chemistry; understanding polymer chemistry; materials science; assessment; analyzing student understanding; from the archives: battery explorations.
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.
Many teachers have students draw models and diagrams to help them illustrate how matter behaves. Teachers can uncover and address possible misconceptions quickly using this strategy. The author describes how to create interactive particle diagram activities that are easy for students to use online. This strategy is applicable to almost any particle diagram and should be useful for teachers during virtual lessons.
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.