Fruit Battery Research

Fruit battery research By: Emmanuel Okello

Abstract What I am going to do in my experiment is that I will see how citrus fruit can make a light bulb/motor work.

Hypothesis In my science fair project, I will make a fruit battery. I am going to see how a citrus fruit can make electricity.

Introduction Chemical energy stored in different substances can be converted to electrical energy. This ability is the foundation of design of all batteries. Each battery has two poles usually made of two different metals. One pole is the positive pole and the other is the negative pole. Electrons can travel from the negative pole to the positive pole via a conductor such as a wire. A flow of electrons in a conductor is called electricity and if large enough, it can be used to make an electro magnet, light up a light bulb, or run an electric motor. Inside each battery there are chemicals that cause such chemical reactions. These chemicals in general are called electrolytes. This activity will investigate whether fruits and fruit juices can be used as electrolytes to make batteries. Zinc and copper will be used as

the electrodes. The chemistry behind the fruit cell is as follows: zinc is an active metal and will react readily with an acid. acid's active ingredient is positively-charged hydrogen so a transfer of electrons takes place between the zinc and the acid; the zinc (Zn0) is oxidized to Zn++ and the acid (H+) is reduced to hydrogen gas (H2), which you can see bubbling out around the electrodes.

Materials • citrus fruit (e.g., lemon, lime, orange, grapefruit) • copper nail, screw or wire (about 2" or 5 cm long) • zinc nail or screw or galvanized nail (about 2" or 5 cm long) • light bulbs with 2" or 5 cm leads (enough wire to connect it to the nails)

Procedures 1. Set the fruit on a table and gently roll in around to soften it up. You want the juice to be flowing inside the fruit without breaking its skin. Alternatively, you can squeeze the fruit with your hands. 2. Insert the zinc and copper nails into the fruit so that they are about 2" or 5 cm apart. You don't want them to be touching each other. Avoid puncturing through the end of the fruit. 3. Remove enough insulation from the leads of the light (about 1") so that you can wrap one lead around the zinc nail and one lead around the

copper nail. If you like, you can use electrical tape or alligator clips to keep the wire from falling off the nails. 4. When you connect the second nail, the light will turn on.

Questions •

What is the difference between normal fruits and citrus?

• What is in the citrus fruit? Variables Independent variable: The fruits. Dependent variables: how much electricity the fruits make. Controlled variable: The wires, the nails,