1. Elephant Toothpaste

2. PROBLEM STATEMENT
How does the amount of yeast added to hydrogen peroxide affect the time it takes the foam to reach the rim of the water bottle?

3. BACKGROUND INFORMATION
Hydrogen peroxide is part hydrogen and part oxygen
The yeast is a catalyst (a substance that causes a change in another substance)

4. HYPOTHESIS If _______________ (independent variable) has an affect
_______________(dependent variable), then ___________
____________ (provide an answer to your problem
statement).

5. Materials 2 empty 16 oz water bottles 3 packets of yeast
240 mL of hydrogen peroxide
Food coloring (color of your choice)
30 mL Dish soap
2 Funnels
Timer
2 Cups
100 mL of warm water
2 spoons
Graduated cylinder
Goggles
Tbsp

6. PROCEDURES Label your bottles “1 tbsp. yeast” and “2 tbsp. yeast”
Place bottles side by side in tub or tray
Place funnel on each bottle opening
Pour 120 mL hydrogen peroxide into both bottles. (Hydrogen peroxide can irritate skin and eyes, so put on those safety goggles, and pour carefully).
Add 8 drops of your favorite food coloring into each bottle.
Add 1 tbsp of liquid dish soap into each bottle and swish the bottle around a bit to mix it.
Mix 50mL of warm water and 1 tbsp. of yeast in a separate small cup, for about 30 seconds.
Mix 50 mL of warm water and 2 tbsp. of yeast in a another small cup, for about 30 seconds.
Pour the yeast water mixture into the appropriate bottle one at a time and start your timer
Observe the time it takes the foam to reach the rim of the bottle.
Record the time on your chart.

7. DATA BLOCK 1 BLOCK 2 # of Tbs Table 1 (Seconds) Table 2 Table 3
Average 1 x
18.91
8.81
8.27
8.99 2 8
11.7
5.03
19.46
11.04
BLOCK 2
# of Tablespoons
Table 1 (seconds)
Table 2 (seconds)
Table 3 (seconds)
Table 4 (seconds)
Avg. (seconds) 1
5.2 X
12.75
5.25
5.8 2
3.3
2.76
4.35
2.6