Electricity Produced by Citrus Fruits in a Voltaic Cell
Researched by Audra S. 2001-2002	PURPOSE  HYPOTHESIS  EXPERIMENT DESIGN  MATERIALS  PROCEDURES  RESULTS  CONCLUSION  RESEARCH REPORT  BIBLIOGRAPHY  ACKNOWLEDGEMENTS  ABOUT THE RESEARCHER

The purpose of this experiment was to determine which type of citrus fruit produced the most electricity when used in a galvanic cell.

I became interested in this topic when I heard about our country's electricity shortage.

Astronauts and poor countries with an abundance of fruit but a lack of electricity could use the information gained from this experiment 

My hypothesis was that the fruit with the most pH (most acidic) would create the most electricity.

I base my hypothesis on scientists that say electricity travels well through acidic substances and things that contain acids.
 

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• The size of the fruit (10cm).
• The type of metals (Iron and copper).
• The room temperature (21 C).
• The temperature of the fruit (21 C).
• The length of time measuring electricity (1 hour).
• The number of tests done on each fruit (5).

The manipulated variable was the types of fruit tested (grapefruit, lemon, lime, oranges).

The responding variable was the amount of electrical milli-volts a citrus fruit would create. 

To measure the responding variable I used a milli-voltmeter. 

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1. Take your grapefruit and cut it in half. SAVE BOTH HALVES!!!!!

2. Hold the pH meter onto the fruit and click "collect." 

3. Do these steps 2 more times, but move the pH collector to 2 different parts of the fruit.

4. Get the other half of the grapefruit and repeat steps 1-3 on it. SAVE THE HALVES!!!!!

5. Repeat steps 1-4 but use an orange. SAVE BOTH HALVES!!!!!

6. Repeat steps 1-4 but use a lime. SAVE BOTH HALVES!!!!!

7. Repeat steps 1-4 but use a lemon. SAVE BOTH HALVES!!!!!

8. Now we’re going to measure the milli-volts of each fruit.

9. You will only need the lid of the voltaic cell kit.

10. Take half of the grapefruit and put it into the bowl.

11. Put the kit lid so both metals are in the fruit.

12. Attach the milli-volt meter to the screws sticking up.

13. Turn on the milli-volt meter to milli-volts.

14. The first number you see remember it, then turn off the meter quickly.

15. Write that number down on an organized chart.

16. Repeat steps 14 and 15, 2 more times on this half.

17. Take the other half of the grapefruit and repeat steps 14 and 15. 

18. Record all measurements

19. Repeat steps 1-18 but use 1 orange.

20. Repeat steps 1-18 but use 2 limes.

21. Repeat steps 1-18 but use 2 lemons.

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The original purpose of this experiment was to determine which citrus fruit produced the most electricity.

The result of the experiment’s milli-volt values were, oranges 0.613, grapefruit 0.743, lime 0.719, and lemons were 0.828. The result of the experiment’s pH values were oranges 4.3, grapefruits 3.7, limes 3.3, and lemons 2.7.

See tables and graphs

My hypothesis was that the fruit with the most pH (most acidic) would create the most electricity. I base my hypothesis on scientists that say electricity travels well through acidic substances and things that contain acids. The results indicate that this hypothesis should be accepted.

Because of the results of this experiment, I wonder if different metals change the amount of electrical charges, citric acid isn’t the only acid in citrus fruits.

If I were to conduct this project again I would have done more trials, used a wider variety of fruits, kept a more accurate record of information, used a more accurate milli-volt meter, kept more organized data, and cleaned the beaker more thoroughly. 
 

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RESEARCH REPORT There is one main source of electricity, man made (nuclear, chemicals, wind, solar, hydropower, and fuel-fired) but natural (lightning and static electricity) is another way. There is a problem with all of these ways of producing electricity. Most of them are too expensive and unavailable we should use an alternative way of producing electricity, a way of using unwanted and recycled items, a way that is environmentally friendly and inexpensive, that way is through citrus fruits! ELECTRICITY   History G. Johnstone Stoney, an Irish physicist, had a theory that electric currents are really movements of nearly invisible electrical particles. He suggested that these particles be called electrons, in 1891. Joseph John Thomson, an English physicist, showed that electrons existed in 1897. An American physicist, Robert A. Millikan, accurately measured an electron’s charge in 1913. In the late 1800’s was when scientists discovered that electrons could be separated from metal surfaces in vacuum tubes. Vacuum tubes are glass tubes with most of the air removed. The tube contains electrodes with wires that extend through the glass, linking batteries to the electrodes it caused a current of electrons to flow through the electrons inside the tube. Adjusting the voltage can change the current. Vacuum tubes can amplify, mix, and separate weak electric currents. The vacuum tube made the radio, TV, light bulb, and other electrical inventions possible. In 1947, American physicists John Burdeen, Walter H. Bratten, and William Shocky invented the transistor. Vacuum tubes and transistors do almost the same thing, accept transistors are smaller and more durable, and they use less energy. By the 1960’s transistors had replaced vacuum tubes in nearly all-electronic equipment. Since the 1960’s electronic companies have developed even smaller transistors, to fit on a single chip called an integrated circuit.  Uses Electricity is used very widely. It’s even used in animals and people. It controls our nervous system. Everything manmade you look at you wouldn’t usually think about who or what made it because people don’t hand make the things you use, electrical machines do, like sewing machines, and other electrical machines make those electrical machines. So every single machine uses electricity or was produced with electricity. Conductors and Insulators Electricity will only travel through certain materials called conductors. Conductors are metals, (iron, copper, and zinc) water, acid, and many other substances. Electricity also refuses to travel through some substances, like wood, rubber, plastic, paper (made from wood), pastes, and natural substances (such as rocks, leaves, and dirt.) They are all called insulators. How Electricity is Produced Several things like wind and water pressure can produce electricity. Man made electric harnesses such as windmills; generators and dams are used to create electrical power to run all of our cities and towns. Lightning and static electricity happen naturally and cannot be harnessed. FRUIT   History Fruit history goes back to when trees and shrubs were first developing and finding ways to spread their seeds all over the continents. Different ways plants reproduce are by: spores, seed by wind travel, seed by animal travel (spikes to attach to furry creatures) and fruit, which is eaten with seeds and digested into soil, undigested seeds in dung is given a chance to reproduce trees and shrubs.  What Fruit Is  Botanists classify cucumbers and tomatoes as fruits because their meat is like that of a fruit, such as watermelon, apples, and oranges. Though a horticulturist would define and classify fruit as a semisweet, edible, seed bearing structure that consists of fleshy tissue and produced by a perennial. So a horticulturist, like most people, would classify cucumbers, tomatoes, rhubarb, broccoli, and cauliflower as a vegetable. Uses Fruit is vital to a healthy diet and our economy (If fruit didn’t exist many farmers would be out of business). Fruit gives us loads of vitamins and minerals. It also gives jobs to people who farm and work at stores and markets. Kinds Fruit comes in many different varieties and types with different kinds of vitamins within them. Many fruits contain vitamin C, like citrus fruits and berries but only citrus fruits have a plentiful source of citric acid. Apples, are in a completely different category. They are in the rose family. Melons, like cantaloupe and honeydew, also have a different group all to themselves. They are mostly made up of water and their seeds are scattered, in small groups, inside the fruit. The Usage and Importance Fruits have a major roll in our diet. People eat and drink fruit products every day. Kind of like those fruit snacks you had in your lunch the other day or the orange juice you drank for breakfast this morning. You eat fruit all the time without really noticing it.  Fruit is also used for making money. The farmers grow the crops. Then they sell it to large companies who sell their fruit products to grocery stores who sell those products to the public. Some farmers just sell to the grocery stores directly. So fruits are used as an item for selling and used as food and daily nutritional value.   Conclusion So in conclusion in the future we should consider making usage of our wasted and unwanted citrus fruit products by creating environmentally healthy electricity through them. This project will show everyone that there is another way of helping our planet to become healthy once more.  Top of page

BIBLIOGRAPHY   "Acid "World Book Encyclopedia, 1998 p.26 and 27 "Battery" World Book Encyclopedia, 1998 p.168-171 "Citric acid" World Book Multimedia Encyclopedia, 2001  "Current Electricity" Encarta Encyclopedia, 2001  "Electricity all Around" World Book’s Young Scientist, 1997 p.49-50 "Electricity" World Book Encyclopedia, 1999 p.190-198  Gardener, Robert Science Projects about Electricity and Magnets Enslow Publishers, Inc., 1994 Parsons, Alexandra Make it work! Electricity Baker, Wendy and Haslann, Andrew 1997

ACKNOWLEDGEMENTS
I would like to thank the following people for helping me with my project. Without their help my project would not have been possible or at it’s very best.
* My friend and classmate Kristyn for giving me the idea of doing this experiment and project. 
* My mom and dad for transporting me to the early SOAR classes and other science functions.
* Mrs. Helms for helping me with any thing I needed help with.
* Mrs. Hostetler for encouraging me to do my best.
* But mainly Mr. Newkirk for being my SOAR teacher, teaching me how to make a science project, for encouraging me, for helping me, lending me the pH meter and milli-volt meter, for guiding me in the processes of my science project and for putting up with all of the kids in the SOAR classes.
 
 
 

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