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The materials required for this science fair project:
- 1 potato
- 7 beakers
- 7 test tubes
- 1 hot plate
- 1 packet of ice
- 1 bottle of hydrogen peroxide
- 1 stop watch
- 1 thermometer
- Marker pen


1. For this experiment, the independent variable is the temperature of the potato and hydrogen peroxide. The dependent variable is the reaction in the test tube. This is determined by counting the number of bubbles formed in the test tube. The constants (control variables) are the amount of hydrogen peroxide in the test tube and the size of the cut potato.

2. The potato is cut into 8  small cubes  of  5mm x 5mm x 5mm.

3. The 8 beakers and 8 test tubes are marked 1  to 8 with the marker pen. The test tubes are each  marked with a line 20mm from the bottom of the tube. The hydrogen peroxide solution is poured into the 8 test tubes up to the level of the line.

4. The 8 beakers are filled with water up to 6cm high. By adding some ice to the water, the temperature of the first beaker 1 is brought to 15°C. Using the hot plate, the temperatures of the water in beakers 2 to 8 are brought to 25°C, 35°C, 45°C, 55°C, 65°C and 75°C. Place the test tubes marked 1 to 8 into the beakers marked 1 to 8 accordingly. At the same time also put one piece of  cut potato into each beaker. Allow the test tubes and the potato’s temperature to stabilize in the water for 5 minutes. Measure the temperature of each tube using the thermometer.

5. Put the potato from the 1st beaker into the test tube of the same beaker. Start the stopwatch and count the number of bubbles released in the next 20 seconds. Record the measurements in the table below.

6. Repeat  procedure 5 for the remaining 7 beakers and record all the results in the table below.

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Complexity level:
Project cost ($):
Time required:
1 hour to prepare, 1 hour for the science project experiment
Material availability:
Access to basic laboratory equipment required
Safety concerns:

Be careful when using the hot plate.