Louis W. Bixby
Dryden Central School Dryden, New York
A Reagent Bottle for Dispensing Insoluble Gases
The average time available for laboratory in a high school chemistry course usually runs about fifty minutes. This allows little time for bending glass tubing and assembling equipment for the generation of oxygen, hydrogen, or other gases. As valuable as the development of these techniques may be, they take second place (in the writer's opinion) to observation of the actual chemistry involved. With this in mind, and with a budget insufficient for purchasing bottled gases, the "reagent bottle" for insoluble gases was developed. Hydrogen or oxygen gas is collected over water in two-quart (or larger, if preferred) bottles, which are corked and stored. When a gas is needed, a bottle is fitted with the diagrammed apparatus. The delivery tube is placed in a pneumatic trough fitted with a collecting bottle. The pinch clamp is removed and another collecting bottle of water is poured through
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the thistle tube. The water replaces the gas, which thus can he collected in samples of predetermined volume. Six two-quart bottles are usually sufficient for a class of twenty-five or thirty students for oxygen or hydrogen experiments. This method has two other obvious advantages: (1) it saves on chemicals and, (2) it eliminates the dangers involved when students work with hydrogen generators and with potassium chlorate. The apparatus also works well as a hydrogen source for blowing up balloons.
