Science Lab Experiment: Preparation of Carbon Dioxide
Demonstration: Action of Yeast
Object: To determine some of the characteristics of the micro-organism "yeast".
Materials: 1 package dry yeast, stand and clamp, collecting bottles, sugar,
collecting trough, water run-off collector, side-arm flask,
rubber stopper, rubber tubing, water
Method: The materials were set up as shown in the diagram.
The gas was collected and tested.
Observations: Bubbles of gas were noticed in the side-arm flask
and during a period of 50 minutes, completely filled the
collection bottle. The gas appeared colourless and odourless.
When tested with a glowing splint, the gas proved to be
carbon dioxide, as it did not support burning. The gas could be
poured onto the flame (putting it out), showing it was heavier
than air. This is another characteristic of carbon dioxide (CO2).
Conclusions: One of the products of yeast action is carbon dioxide.