- Lemon battery
A lemon battery is a device used in an
experiment proposed in many science textbooks around the world. [ [http://www.hilaroad.com/camp/projects/lemon/lemon_battery.html Lemon Battery ] ]It consists of inserting two different
metal lic objects, for example a galvanized nail and acopper coin, into alemon . The copper coin serves as the positive electrode or cathode and the galvanized nail as the negative electrode or anode. These two objects work aselectrode s, causing an electrochemical reaction which generates a smallpotential difference .The aim of this experiment is to show students how batteries work. After the battery is assembled, a
multimeter can be used to check the generatedvoltage . In order for a more visible effect to be produced, a few lemon cells connected in series can be used to power a standard LED. Flashlight bulbs are generally not used because the lemon battery cannot produce the amount of current required to light such bulbs.The energy used to power the circuit ultimately comes from the energy used in the electrode factories to reduce metallic ions forming the solid metallic electrodes. The lemon simply provides a salt bridge for the reaction to occur. In a lemon battery, both oxidation and reduction occur. Consider the case of a zinc-copper battery. At the
anode , zinc isoxidise d::Zn → Zn2+ + 2 e-.At the
cathode ,hydrogen is reduced::2H++ 2e- → H2.Potato es, [ [http://www.unit5.org/christjs/Potato%20Battery.htm Potato Battery ] ]apple s, or any other fruit or vegetable containingacid or otherelectrolyte can be used, but lemons are preferred because of their higher acidity. [ [http://www.madsci.org/experiments/archive/889917606.Ch.html Food Batteries ] ] Other metal combinations (such as magnesium-copper) are more efficient: for example, using a magnesium strip instead of zinc increases the voltage from 1.1 V with zinc to 1.6 V with magnesium. (The exact voltage varies depending on the lemons.) However, zinc and copper are usually preferred because they are reasonably safe and easy to obtain.Video Demonstrations
* [http://youtube.com/watch?v=AY9qcDCFeVI Lemon Battery]
* [http://www.metacafe.com/watch/800526/orange_battery/ Orange Battery]
* [http://youtube.com/watch?v=m64ogRLvDsI Potato Battery]ee also
*
Electrochemical cell
*Galvanic cell
*Galvanic corrosion#Lasagna cell References
External links
* [http://msdaif.googlepages.com/lemonexperiment EduMation]
* [http://www.electriccircuits.net/book,6,chapter,319,lesson,1476,potato_battery.aspx Potato battery]
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