The concept of "like dissolves like" is explored using a solvent extraction demonstration appropriate for first-year chemistry students. Equal volumes of aqueous methyl red and blue copper(II) sulfate form a purple solution. 1-Pentanol is added and floats on top as a clear layer due to its lower density and low water solubility. Vigorous…

A mixture of salt water and isopropyl alcohol is immiscible, forming two separate liquids with the organic layer on top and aqueous layer on bottom. When universal indicator is added to such a mixture, all of the indicator compounds in the universal indicator preferentially dissolve in the alcohol--except for phenolphthalein at high pH. Mixtures…

The formation of chemical patterns is in general difficult to control due to the random diffusive motions of the reacting chemical species in solution. In this paper, we present a new method using audible sound to control the formation of chemical patterns obtained in blue bottle experiments. The waves generated on the surface of the solution by…

The yellow-blue color pair has been used in creative artwork such as paintings and designs and in color engineering. Herein we present a method for using the yellow-blue combination in a chemistry lesson dealing with [pi]-conjugated molecules for first-year undergraduate students who are not science majors. The lesson begins with an introduction…

For decades, chemical modeling sets have allowed the user to manipulate atoms and bonds using plastic/wooden ball and stick materials. Here is a design for an interlocking toy brick modeling set in which the undergraduate nursing student can manipulate electrons during the simulated chemical bonding exercise. The author presents a teaching and…

Blue (B), yellow (Y), red (R), and green (G) color-changing dye was used in a general chemistry course for first-year undergraduate students with nonscience majors to highlight the redox reactions written as the gain and loss of hydrogen. The first experiment is a vibrant color variation using a synthetic dye of indigo carmine. The second…

For the present lab demonstration, we have developed fluorescent indicators to detect the end point in microscale redox titration of ferrous ions in permanganometry, cerimetry, and dichrometry. Microscale redox titrations were carried out effectively in micromolar(µM) concentrations and semi-microvolumes of the analytes. At the end point,…

The notion of a boundary condition is typically considered to be somewhat advanced and not suitable to be introduced in high school level physics. In this article, we give a simple visual demonstration of the difference between Dirichlet and Neumann boundary conditions for a string which oscillates according to the one-dimensional wave equation.…

The mercury beating heart is a dramatic demonstration of redox chemistry that allows for the direct conversion of chemical energy to mechanical energy without involving a machine to accomplish the transfer. Unfortunately, instructors often avoid this demonstration due to difficulties initiating the oscillating redox reaction that drives the…

In this paper, we discuss a demonstration we have been performing for years with students from different levels, from physics students from our university to high school students in some talks aimed at encouraging them to study science. It provides visualization of Brewster's angle in an ingenious way using a "loaded" liquid crystal…

Lesson planning is a challenge for teachers. However, the measurement and modelling of teachers' competence to plan lessons has received little attention. Especially, the question of which aspects are of central importance remains largely unresolved. The study aims to measure the challenge of structuring a lesson as an aspect of the…

Potassium tris(oxalato)ferrate(III) trihydrate is a commonly prepared coordination compound in general or upper-level chemistry laboratories and can be recycled to grow large single crystals that instructors may display when introducing the experiment to classes. Showing the crystal's shape can also be used to briefly introduce students to X-ray…

Since its debut in Elihu Thomson's 1886 article "Novel Phenomena of Alternating Currents," the Thomson jumping ring apparatus has been a popular and captivating demonstration of magnetic induction. The components are quite simple. There is a solenoid, an iron core, and a ring. The demonstration usually begins with the professor saying…

The current meta-analysis quantifies the average effect of worked examples on mathematics performance from elementary grades to postsecondary settings and to assess what moderates this effect. Though thousands of worked examples studies have been conducted to date, a corresponding meta-analysis has yet to be published. Exclusionary coding was…

Engineering educators naturally gravitate toward visual means for communicating concepts that would otherwise be extremely difficult to convey using words and numbers alone. With the emergence of three-dimensional (3D) printing as an accessible and cost-effective technology, it is now possible to develop customized models that enable students to…