Report for Voltaic Cell Project (Lemon)
The purpose of the experiment is to demonstrate the production of electricity through the use of Zinc, Copper and Lemon. The experiment explores the electrochemical reactions that take place between the two metals in the presence of citric acid provided by the lemon to generate electricity. It highlights the oxidation and reduction reactions that occur within the lemon battery before electrons are released to generate electricity.
Background
The electrochemical reaction that occurs to generate electricity from chemical energy takes place between tow metal pieces, known as the electrodes, and a liquid known as the electrolyte. It is imperative that the two electrodes are made up of different metals for the voltaic cell to work. The difference in electrode material ensures that they react differently with the electrolyte thus releasing electrons (Amin 217).
The lemon battery is composed of two different metals; copper and zinc nail. The two metals form the electrodes used in the voltaic cell. Lemon battery is composed by placing the zinc nail and the copper metal in lemon juice present inside the lemon. The juice acts as the electrolyte since it is citric acid. In a solution of an electrolyte and water, similar to citric acid in the lemon, electrons are lost from one end of the metal electrodes while an excess of electrons is gathered at the other end of the metal electrodes. Electricity is generated through this process.
Experimental Procedure
The following materials were used in the experiment: Lemon, Zinc nail, Copper Metal, Aluminum, a strip of wire and voltmeter.
Procedure
The lemon was squeezed without breaking its skin so as to loosen up the acidic juice inside needed for the battery to function. It was rolled on the table several times while applying gentle downward pressure. A small slit was cut through the rind at the centre of the fruit. The slit was made large enough to allow for insertion of the metal electrodes later.
The metal copper was inserted firmly into one end of the lemon while the zinc nail was inserted on the other end of the fruit. The electrodes were placed closer to each so as to allow for chemical reaction needed for the operation of the battery. Care was taken to ensure that the copper metal and the zinc nail do not touch inside the lemon (Amin 217). The voltmeter clips were connected to the metal electrodes to measure the voltage across the lemon. The collected data was recorded as follows. The same procedure was repeated using copper and aluminium metals as the other electrode combination.
Data table
Oxidation Reduction Equation
Zinc atoms react with the citric acid electrolyte as electrically charged zinc ions (Zn2+) resulting into two negatively charged electrons.
Zn Zn2+ +2e-
On the other end of the copper electrode, two positively charged hydrogen ions from the electrolyte join with the two electrons to generate an uncharged hydrogen molecule (youtube.com).
2H++ 2e− → H2
Conclusion
The use of different electrode materials produces different voltages as seen from the experiment. Zinc electrode produces more voltage (1.25 V) as compared to Aluminum electrode (0.6V).This outcome is as a result of the amount of electrons released during the oxidation reaction. The lemon cell is known as a voltaic battery which transforms chemical reactions into electrical energy. Batteries are holders used to store chemical energy that can be converted to electrical energy (Amin 217). A voltaic cell relies on electrochemical reaction to produce electricity. The difference in electrode material ensures that they react differently with the electrolyte thus releasing electrons.
Works Cited
Amin, Mohammad. "Electrochemical Analysis of Fruit and Vegetable
Freshness." the WSEAS Transactions on Biology and Biomedicine 2 (2000): 214-219.
ScienceMadeEasy,. How A Lemon Battery Works.. 2016. Web. 14 Aug. 2016. Retrieved from
https://www.youtube.com/watch?v=ecYc85Qz710 [Accessed 14 Aug. 2016].
