Variations on the "Whoosh" Bottle Alcohol Explosion Demonstration Including Safety Notes

Abstract

The explosion or burning of methanol, ethanol, n-propanol, and isopropanol in large small-necked bottles when ignited with a match has been studied with respect to the nature of the alcohol, temperature, concentration dilutions with water, oxygen concentration, plastic versus glass bottles, and salts added for color. The various effects are explained in terms of vapor pressures. Safety guidelines are emphasized.

Demonstration Show That Promotes and Assesses Conceptual Understanding Using the Structure of Drama

“…This may be, in part, due to the spectacular nature of the demonstrations, but they are unlikely to be the main reason, as The Boiling Point presented only three demonstrations that occupied only 5–10 min of the entire show. The demonstrations of The Boiling Point were also objectively less spectacular than other popular chemistry demonstrations (e.g., Elephant’s toothpaste, Genie in a Bottle, Whoosh Jug). Therefore, there must be an additional cause for the high level of interest in The Boiling Point .…”

Improvements to the Whoosh Bottle Rocket Car Demonstration

“…It is well-known that the whoosh bottle demonstration works with a variety of simple alcohols as fuels, and many previous observations about the relative reactivity of the fuels can be extended to the effectiveness of the rocket car demonstration. 3 Among the more common, readily available alcohols (methanol, ethanol, and 2-propanol), methanol produces the most thrust and 2-propanol produces the least. Pure alcohol fuel produces greater thrust than alcohol/water mixtures.…”

“…Even though these authors have NEVER had a problem using methanol as a fuel (the most that gets burned is 1.5 mL at any one time), the wellfounded concerns about the safety of burning methanol are so great that 2-propanol seems to be the more desirable, albeit weaker, option. 3,10 Shaking the closed bottle helps the alcohol to evaporate. Three minutes of shaking often produces more thrust than 1 min of shaking, and both amounts of shaking produce more thrust than no shaking at all.…”

“…The “whoosh bottle” demonstration is a well-established demonstration of thermodynamic principles and gas laws in chemistry. − The demonstration is based on combustion of alcohol vapors in an open-mouthed bottle. The vapor/air mixture is initially ignited by a flame held near the mouth of the bottle.…”

Playing with Fire: Chemical Safety Expertise Required

“…In the demonstration a row of dishes (each containing a different salt) will produce a flashy display of multiple flame colors simultaneously, thus emulating the color order of a rainbow. Variations of this demonstration include the following: spraying methanol/salt solutions into a flame, the “green fire tornado”, the “whoosher bottle”, and alcohol-fueled rockets. − …”