Chemical Reaction #2

Experiment # 7: Energy + Chemical Reaction

This activity will show how energy added to a chemical reaction increases the rate at which products are formed.

Materials Needed:
* 3 large test tubes
* 3 small test tubes
* 3 water baths
* yeast
* sugar (Karo syrup)
* ice
* heat source

Procedure:
1. Put a small amount of yeast into a glass jar. Add 1/3 cup of warm water. Stir until dissolved.
2. Fill the small test tubes with the scant solution of yeast and a small amount of sugar.
3. Invert the large test tubes over the smaller ones; then invert again so smaller ones are mouth down inside the larger ones.
4. If an air space occurs in a smaller test tube, measure its height and record.
5. Place one test tube in an ice bath, leave the second set at room temperature, and the third in a warm water bath.
6. Record the height of the gas columns for each tube at the start and for every 15minutes interval for 1 hour.

Note: The yeast cells are undergoing cellular metabolism,producing carbon dioxide, being collected int he small inverted test tubes.

@ 0 minutes

@60 minutes, L-R: room; cold;warm

Question:
* Which tube did the yeast produce the most gas?
* What is the effect of temperature (Energy) on the chemical reaction taking place?

Findings:
* Warm set produced more gas (CO2)
* We therefore conclude that, when subjected to high temperature, there was rapid rate of reaction.