While lecture demonstrations have been conducted in chemistry classrooms for hundreds of years, little research exists to document the frequency with which such demonstrations are employed or their effect on learners' motivation and performance. A mixed-methods research study was performed, using quantitative and qualitative survey data, along…

As it connects to a large set of important fundamental ideas in chemistry and analytical techniques discussed in high school chemistry curricula, we review the exploding flask demonstration. In this demonstration, methanol vapor is catalytically oxidized by a Pt wire catalyst in an open container. The exothermicity of reactions occurring at the…

A revisitation of the classical "mushroom cloud" demonstration is described. Instead of aniline and benzoyl peroxide, the proposed reaction involves household chemicals such as alpha-pinene (turpentine oil) and trichloroisocyanuric acid ("Trichlor") giving an impressive demonstration of oxidation and combustion reactions that…

The circuit board found in a commercial musical greeting card is used to supply music for electrochemical cell demonstrations. Similar to a voltmeter, the "modified" musical device is connected to a chemical reaction that produces electricity. The commercial 1 V battery inside the greeting card circuit board can be replaced with an…

The esterification reaction of salicylic acid with ethanol is performed in presence of dissolved 12-tungstophosphoric Brønsted-Lowry acid catalyst, a Keggin-type polyoxometalate (POM). The monitoring of the reaction with smell and the recovery of the catalyst with sight is presented. Formation of the sweet-scented ester is apparent from the smell.…

This article demonstrates how to make a low-cost ethanol burner utilizing soda cans. It burns with a light blue flame suitable for out-of-laboratory flame test demonstrations where interference from a yellow flame needs to be avoided.

Poly(vinyl alcohol) (PVA) precipitates in many kinds of aqueous salt solutions. While sodium sulfate, a coagulant for PVA fiber, precipitates PVA to yield a white rigid gel, coagulation of PVA with aluminum sulfate, a coagulant for water treatment, yields a slime-like viscoelastic fluid. One type of homemade slime is prepared under basic…

A demonstration of the degradation of food coloring dyes by oxidation via the Fenton reaction can be substituted with a simpler demonstration using the oxidant oxone with iron(II) ions as an activator. The addition of small amounts of solid oxone and iron(II) sulfate to solutions containing mixtures of food coloring results in successive…

A modified technique for demonstrating the magnitude of Avogadro's number using a new Raspberry Pi computer and the Python language is described. The technique also provides students the opportunity to review dimensional analysis.

Everyone enjoys seeing the cloudy white fog generated when solid carbon dioxide (dry ice) is placed in water. Have you ever wondered what physical and chemical processes occur to produce this fog? When asked this question, many chemical educators suggest that the fog is produced when atmospheric water vapor condenses on cold carbon dioxide gas…

This article describes two simple classroom demonstrations that illustrate the principles of scanning probe microscopy (SPM) based on a macroscopic analogy. The analogy features the bumps in an egg carton to represent the atoms on a chemical surface and a probe that can be represented by a dwarf statue (illustrating an origin of the prefix…

During electrolysis, to visually observe the conversion of a metal to its cation, either the cation or its complex ion should have a distinct color while the electrolyte solution must be colorless and transparent. A demonstration is described in which copper is used as the electrodes and sodium polyacrylate (a superabsorbent polymer) solution is…

A simple, effective demonstration of the concept of limiting and excess reagent is presented. Mixtures of either air/methane (from a gas line) or air/butane (from a disposable cigarette lighter) contained in a plastic 2 L soda bottles are ignited. The mixtures combust readily when air/fuel ratios are stoichiometric, but not at a 2-fold excess of…

LEGO bricks can be used for a number of demonstrations of chemical structures and properties, especially at the nanoscale level. These bricks can also be used to model instrumentation that probes these structures and properties. Detailed resources about many of these demonstrations are located on the extensive Web site "Exploring the Nanoworld…