How to Do a Science Fair Project on Chemistry

Oranges for food science chemistry.

Science fair projects are an important of junior high and high school curricula. Advanced science subjects, like chemistry, provide absorbing experiments for teachers and students to share at the fair. Food science is one part of chemistry that attracts attention. The experiment to determine much water makes up in an orange can be an ideal science fair project for junior high.

Things You'll Need

• Fruit (Orange, Apple, Pineapple)
• Serrated knife
• Paper plate
• Foil
• Kitchen food scale
• Composition book

Instructions

1. Choose the fruit you will use and write your hypothesis. Since oranges are filled with juice and water, this experiment will show how much of those liquids comprises the total weight. For example, you may state in your hypothesis that you think 50 percent of the orange's weight is juice. For the first experiment, use an orange.

2. Prepare your experiment. For accurate results, weigh the paper, oranges and foil separate to get each weight. Write down your data in the composition book.

3. Cover the paper plate with foil. Thinly slice the orange with a serrated knife, and place the orange slices on the foil, arranging them so overlapping is minimal.

4. Place the oranges outside in a well-ventilated area, and weigh them every 2 to 3 hours to record the drying process. Record your data in the composition book.

5. Weigh the orange slices once they are dried out. Subtract the weight of the foil and plate to get an accurate measurement of the dried fruit. To find the percentage of solids in the orange, divide the dried weight by the original weight. For example, if the orange started out weighing 300 grams, and now weighs 50 grams you will set up the equation like this: (50/300 = 0.1666). To determine the percentage of water in the fruit, set up the equation like this: (300-50)/300 = 0.8333, or 83 percent water.

6. Try using different fruits to see if all fruits have the same chemical makeup and water content.

References

• All Science Fairs: Water in Fruit