Addition of a small amount of azobenzene to eicosane can lower its melting point to where it can be melted by body heat. This can be used in demonstrations and classroom activities related to freezing point depression and phase diagrams.
Thermal paper such as that used for point of sale receipts typically functions by darkening when exposed to heat. The pigment system used in this paper also darkens when exposed to solvents of intermediate polarity and acids. This enables thermal paper to be used as an inexpensive sort of indicator paper for a variety of demonstrations.
Students use a micro-scale method to extract caffeine from tea using dichloromethane. At the end of the activity, the students' dochloromethane extractions are pooled; the solvent is distilled after class for re-use.
Boredom needs no explanation; we were all (Chemistry) students. A bored student is not an engaged student, and likely not a student who wants to learn. How can we make our lessons more engaging?
Assembling a large graduated cylinder with colored sugar solutions of various densities is described. By filling the cylinder in the reverse order from bottom up, very little mixing occurs resulting in an attractive classroom demonstration to illustrate density. Students also have to opportunity to practice density and dilution calculations.
Ben Meacham decided to alter his approach to teaching about enthalpy and focus on getting students to first develop the mathematical model for enthalpy of solution so they could eventually apply it to make predictions for different solutes being dissolved. In this blog post he shares the process he used with his class.
This demonstration offers an alternative to the disappearing rainbow demonstration using readily accessible materials.
In this activity, students learn about solubility and concentration. They watch videos that explain the dissolving process, how to calculate the molarity, supersaturation and how to make rock candy. They also use a PhET simulation to explore factors that affect the concentration of a solution.
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).
Two groups of students, typically, have difficulty with titrations, the first time around. Those that act too rashly and overshoot the endpoint, and those over-cautious ones who they take forever to finish.
