Beetroot Experiment Write-Up
Hypothesis: The higher the temperature, the more permeable the beetroot will be.
Independent Variable: The temperature of each test tube.
Dependant Variable: The transmission of light through the beetroot water.
Control Variables: The volume of distilled water in each boiling the tube, the volume of each beetroot section in each boiling tube, the time each boiling tube is left in the water baths, and the volume of dye solution in the curvette.
Size 4 cork borer
Water baths at 0°C, 20°C, 40°C, 57°C, 70°C
5 boiling tubes
Boiling tube rack
Thermometers, (one per water bath)
Small measuring cylinders
Take care when handling cork borer, scalpel and water baths.
Wear a lab coat or cover up clothes in case of beetroot juice spillages or splashes.
1. Cut sections from a single beetroot using a size 4-cork borer. Then cut eight 1cm length slices from these sections.
2. Place the slices in a beaker of distilled water and leave overnight to wash away excess dye.
3. The next day, place eight labeled boiling tubes each containing 5cm³ distilled water into water baths at 0°C, 20°C, 40°C, 57°C, and 70°C. Then leave for 5 minutes until the water reaches the required temperature. Place one of the beetroot sections into each of the boiling tubes and leave in the water baths for 30 minutes.
4. Pour the liquids into second boiling tubes or remove the beetroot sections carefully and shake the solutions to disperse the dye.
5. Set up the colorimeter and set it to read % absorbance.
6. Set the filter dial to the blue/green filter.
7. Using a pipette, measure 2cm³ distilled water into a cuvette. Place the cuvette into the colorimeter; making sure that the light is shining through the smooth sides.
8. Adjust the colorimeter to read 0 absorbance...