MODERN ALCHEMIST

"Exploding Balloons"
Dalton, Lavoisier, and Avogadro
Combining theories to build ideas...

We find an experiment in a text where they say that if you put oxygen and hydrogen in a balloon, attach the balloon to a yardstick, and then pass the balloon over a candle flame, it will explode with a bang that results from the reaction of hydrogen and oxygen to form water.

Focus Ideas

"Dalton" - If we react A and B to form C, A and B react in a specific proportion. If we don't achieve this proportion, we will have unused A or B at the end of the reaction.
"Lavoisier" - Oxygen reacts with hydrogen to form water.
Avogadro - We can fill a series of balloons with different mixtures of oxygen and hydrogen, but as long as we fill each balloon to the same total volume, each balloon will have the same number of molecules. If all balloons in the experiment contain the same number of molecules, it stands to reason that the balloon with the most efficient reaction (i.e., the balloon in which all the oxygen and hydrogen is converted to water) will produce the loudest bang.

Given that oxygen and hydrogen combine in a two:one ratio, which mixture below will give the loudest "Bang!"?

Experiment	Hydrogen	Oxygen
#1	20 liters	4 liters
#2	18 liters	6 liters
#3	16 liters	8 liters
#4	14 liters	10 liters
#5	12 liters	12 liters

#1- Excess hydrogen, 4 liters of water formed

#2- Excess hydrogen, 6 liters of water formed

#3- Correct stoichiometry, 8 liters of water formed- loudest bang

#4- Excess oxygen, 7 liters of water formed

#5- Excess oxygen, 6 liters of water formed

Thought questions: When reading about Dalton and the Lavoisiers, which theories and laws are each responsible for? Is it possible that their work overlaps on an idea or two? Did one build on the work of the other (i.e., one was aware of the other's work and added to it?)

Next Page

Return to Master Alchemist Index