Lemon Battery Experiment - Science

🍊 Lemon & Orange Battery 🍋

Aim: I want to investigate which fruit works better ( Lemon Battery or Orange Battery )

Equipment: Orange, Lemon, Copper Nail, Zinc Nail, Voltmeter, Switch, 3 Alligator Clips, Light bulb.

Method: 

1. Gather all the equipment.

2. Take a lemon or orange and roll it. 

( Without Breaking The Fruit )

3. The aim is to soften the fruit so it releases citrus juice. 

4. Then attach the nails in the lemon, approximately 4 cm apart.

5. When attaching the nails in the fruit be very careful, making sure it won't break.

6. Then clip the alligator clips between the nails and the others from the lemon to the bulb.

7. Observe Results. 

Results: 

Evaluation: 

During the experiment, many things went wrong. The lemon and orange battery didn't light up the 9 volt light bulb. So we decided 9 volts is too high. We changed the bulb to a led light bulb which takes approximately 2 to 3 volts. Our voltmeter only read 0.7 volts the highest. Copper and Zinc metal should only produce 1 volt. There are many reasons why the LED wouldn't have light up:
1. A layer of oxides ( Rust ) was stopping the conduction of electricity. Which is why it's a good idea to clean the metal. 

2. The lemon and orange didn't have enough citric acid. The more acidic a fruit is the more electricity it will generate.

3. Using ripe lemons.

If you were to do this experiment don't use ripe or under-ripe lemons, this is because they don't contain as much juice. Whereas overripe lemons have juice which helps electricity flow.  Clean off the rust properly, otherwise as it says above it will stop conduction of electricity. Also, check that all the wires are working. 

Discussion:

For our lemon and orange experiment, we cut a slit in the lemon and attached copper and zinc nails. Then we connected the zinc metal and copper metal together with an alligator clip. This acted as a conductor, which allowed electricity to flow. We measured the energy the current was carrying with a voltmeter. 

First, we built a circuit. A circuit is a path which the electrons can flow through. For a circuit to be complete charge must be flowing. For a lemon battery to work, you need to have two electrodes and one electrolyte. In this case, we have our to metals (Zn & Cu) as our electrodes and the lemon as our electrolyte. An electrode is where the charges gather, Cu and Zn. An electrolyte is ions in a solution, citric acid. An electrode which wants more electrons is called a cathode and the one which gives up electrons is called the anode.

The electrons are flowing anti-clockwise from zinc to copper through the wire. Zinc and copper both want to lose electrons but zinc is more reactive. Our anode (Zn) has two electrons in its outer shell and wants to lose them. We would say zinc has a higher electronegativity, meaning it has a stronger desire for electrons than copper. By losing these two electrons it now becomes Zn²⁺. The electrons are now going to leave zinc and go to copper, left on zinc are positive charges. This is similar to copper the electrons are going to leave copper and go to zinc, leaving copper with negatives charges. After zinc has lost its electrons it will move freely around the lemon. Inside the lemon is citric acid. Citric acid will dissociate (break apart) into acid, H⁺ ions and citrate. The electrolyte has a negative and positive charge, citrate - and hydrogen +. Citrate is going to go to zinc because positives and negatives attract. Same goes for Hydrogen it will go to copper.

The reaction happening is a redox reaction. Reduction Oxidation. Reduction means when charges reduce or decrease and oxidation means when charges increase. As we know Zn went from having no charge to having 2⁺. This is oxidation. The hydrogen went from 2H⁺ to H₂ ( Hydrogen gas ) and has become neutral. Reduction. This is definitely the reaction that occurred because of one of my peers noticed bubbles, which indicates a sign on hydrogen gas.