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.
This demonstration offers an alternative to the disappearing rainbow demonstration using readily accessible materials.
Have you seen the rainbow candy experiment? It's a very simple experiment that involves pouring water into a plate that has M&M's candies or Skittles arranged in a pattern. Very curious shapes of sharply divided regions form spontaneously. How does this happen?!
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.
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.
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.
The Devil's Milkshake is a simple, yet interesting chemistry experiment that fits well as a Halloween demo.
I have blogged about Argument Driven Inquiry (ADI) previously. It has been a popular topic on ChemEd X lately. During my limited experience, I have found the process to be a bit drawn out but extremely helpful and beneficial. The time spent has been well worth it.
Density Bottles can be used to teach a variety of chemical concepts such as density, solubility, and polarity. In this post it is shown that Density Bottles can also be used to differentiate between heterogeneous and homogeneous mixtures, and to explore light scattering.
