Orange/Lemon Battery

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Page ID: 131417

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Required Training	Required PPE
UC Lab Safety Fundamentals	Lab coat, safety glasses/goggles, nitrile gloves

Equipment	Chemicals
Lemons or Oranges
House setup of Zinc/Copper electrodes
LED light, watch, or voltmeter to measure/visualize current

Procedure:

Insert the Cu and Zn electrodes into the fruit.
Connect the metal clips to an LED light and see it glow (light is dim, so you may need to turn off the lights).
Clips may also be attached to a watch to see the seconds hand move or to a voltmeter to measure the voltage
Increasing the number of fruit will create a high voltage
Be sure to wipe down the electrodes with a paper towel after use

Discussion:

The current derives from the oxidation of Zn metal and the reduction on H⁺ ions. Zn atoms dissolves in the acidic citrus juice leaving 2 negatively charged electrons (e^-) behind in the Zn anode.

Zn → Zn²⁺ + 2 e^-

As Zn enters the solution, 2 positively charged H⁺ ions pick up 2 electrons at the Cu cathode and form H₂ gas.

2H⁺ + 2e^- → H₂

The electrons lost by Cu are replaced by 2 e^- from the Zn anode that have traveled through the wire. The electrical current is produced by the movement of electrons in the circuit. During oxidation, Zn looses electrons to reach a lower energy state; the energy released provides the power to turn on the LED, start the watch, etc.

Hazards:

N/A

SOP

N/A

Disposal (by Storeroom)

Used lemons can be tossed in the trash.