Lightstick Kinetics

Extraction of dyes contained in glow sticks using liquid CO2

“…During the extraction process, it is interesting to note that the glow stick material adsorbed on the cotton loses its glow. This is not surprising, given that it is well known that the kinetics of the chemical reaction in glow sticks substantially decreases with temperature (14,15). However, it is unexpected that both the residue on the cotton swab and the extract begin glowing again after being warmed back to room temperature following the extraction process ( Figure 2, right and Figure 5).…”

“…Chemiluminescence is another topic that has been extensively covered in the chemistry curriculum (9)(10)(11)(12)(13)(14). In fact, chemiluminescent reactions have even been referred to as the most "exocharmic" reactions known, based on the high interest they generate in students and other observers (9).…”

“…In fact, chemiluminescent reactions have even been referred to as the most "exocharmic" reactions known, based on the high interest they generate in students and other observers (9). Chemiluminescent reactions have been used to introduce students to topics as varied as fluorescence, kinetics, thermodynamics, chromatography, catalysis, organic synthesis, and principles of green chemistry (9)(10)(11)(12)(13)(14). Many of these experiments have focused on the chemistry of glow sticks, which provide very easily obtained sources of chemiluminescent reactions.…”

Elephant’s Toothpaste Used as a Qualitative Demonstration of Rate versus Temperature

“…The effect of temperature is one aspect of reaction kinetics (an important topic in chemistry , ) comprising the interrelated topics of collision theory, transition state theory, activation energy, potential-energy diagrams, the Arrhenius equation, − and the Maxwell–Boltzmann distribution. − The elephant’s toothpaste demonstration and the iodide-catalyzed decomposition of hydrogen peroxide, which drives it, are widely used to illustrate or study a variety of topics including catalysis, , rate laws, ,, heat of reaction, , and activation energy, ,, among others. , The elephant’s toothpaste demonstration can be easily adapted to illustrate the effect of temperature on reaction rate qualitatively, but vividly. The effect of temperature change on reaction rate is the subject of many experiments ,,,,,− and relatively few lecture demonstrations. ,− The demonstration described here is designed to meet several goals: Easily performed Suitable for a large class Easily seen and interpreted Uses simple apparatus and easily achieved temperature control Reasonably safe Qualitative Engaging Performed in 5 min or less …”

Reaction of FD&C Blue 1 with Sodium Percarbonate: Multiple Kinetics Methods Using an Inexpensive Light Meter

“…Inexpensive colorimeter circuits as well as smartphone setups have been described previously as economical ways to measure solution concentrations without commercial spectrophotometers. − The experiment described in this paper involves measuring the degradation of the dye using inexpensive light meters with 50 mL solution quantities, which offer the advantage of greater simplicity as well as eliminate the need for water baths, circulators, and jacketed cells for temperature-dependent measurements. Other creative methods which have been used for student measurement of activation energies as documented in this Journal range from gravity-powered flow systems, to magnetic levitation, to water displacement. − The development of efficient, simple, and inexpensive methods for students to measure activation energies continues to be a challenge, and instructors may find our method useful.…”