1. Beaker x10
2. Different pH solutions 3, 4, 5, 6
3. Eggs x20 (4 for control)
4. Paper towels
5. Electronic balance
6. Water (to act as a control)
7. Gloves (for safety reasons)
*Note that the eggshells should be specifically white to better resemble the colour of our teeth.
1. Crack and empty out the contents of 10 eggs. Use 2 eggs for the control
2. Rinse eggshells thoroughly with water.
3. Leave eggshells to dry overnight
4. Put one eggshell at a time on the electronic balance ( Make sure that the air bubble is in the center )
5. Weigh the eggshell using the electronic balance and wait for the numbers on the electronic balance to come to a stop.
6. Record the data on the logbook under "results before experiment".
7. Fill each beaker with 200 ml of the different pH solutions. Soak two eggshells in each of the different pH value (3,4,5,6,7) solution and cover the beaker with a cover. ( To minimise evaporation of the pH solution and possible smell from the eggshells and/or the solution. )
8. Put the beakers side by side under room temperature for 5 days.
9. After 5 days, remove the eggshells, one at a time, from the solution and leave them to dry.
10. Weigh the eggshells using the electronic balance and record the results on the logbook.
2.4 Risk assessment and management
1. We should wear gloves when handling the pH solutions and the eggs as the solutions are acidic and may burn or irritate our skin.
2. Food and pH solutions in the experiment are not meant for consumption. All team members should take note that none of the items used in the experiment is used for consumption.
3. Handle the beakers and eggshells with care as they are brittle and if they are broken or stained, our experiment will be affected.
4. Do not spill the pH solutions as they are acidic . If there is any spillage, immediately clean up the area. If any pH solutions come into contact with our skin , wash thoroughly with water.
2.5 Data analysis
1. Calculate the difference in the weight of the eggshell before and after it was soaked in the solution.
2. Take the average result of the 4 eggs soaked in the same pH solution.
3. Compare the average results of each pH solution by plotting a bar graph.
4. A greater difference in weight before and after 5 days indicates a higher level of corrosion.
5. Conclude if our hypothesis, which is the lower the pH value, the higher the level of corrosion, is correct based on the findings.