SCIENCE FAIR GREEN ENERGY SOURCES.
COMPARISON OF FRUIT ACIDITY FOR A GREEN ENERGY SOURCE. OBJECTIVE The students will test two different fruits and take advantage of their acidity to produce energy and compare which fruit would be more effective as a green source of energy. Hypothesis If we have different fruits then we are going to test their acidity to produce energy and compare which fruit would be better for a green source of energy.
INTRODUCTION. There are many different types of green energy sources but we have decided to make a green battery because this is a way of stop using batteries that contains many metal toxics, we have made this project because we are interested to change the world by making it better and more ecological. By making these kind of green energy sources it will improve the life of every single human being of the planet because it will decrease the contamination and eventually it will be lowering down the wasting of resources to make non-ecological energy sources, it also decreases the possibility of people having serious diseases. The environmental impact of any non-ecological energy sources its very serious because it pollutes the world because of the
materials it contains. A battery made of mercury is able to pollute 600 thousand liters of water, a carbon-zinc battery is able to pollute thousand liters of water, and a battery made of zinc-air can pollute 12 thousand miters of water. Also it pollutes because by manufacturing a battery it wastes 50 times more energy that it provides, the 30% of the materials contained in a battery are toxic. Some kinds of toxics that materials contain are: mercury, lead, lithium, cadmium and zinc. Non-ecological energy sources provide serious effects on human beings health. Some health effects that these elements provide are: mercury causes possible cancer effects in pregnant woman and babies, it also causes deafness, blindness, loss of 2
memories, cadmium causes lung damages and damages in kidneys, lead causes kidney damage, bones damage, joints damage, reproductive and nervous systems damages and serious allergies. The voltage that the fruit provides depends on the acidity of each fruit, the lemon acidity is 5.68 and the acidity of the apple is 0.58. Each fruit contains electrolytes and that is what makes them conduct electricity. Electrolytes are substances that give ions when they are dissolved in water, they are divided by acids, bases and salts. It conducts electricity due to the mobility of cations and anions (positive and negative ions). We decided to make the battery with these specific metals because they are able to conduct electricity. Copper conducts electricity because their outer electrons are not localized, they are not bonded to specific atoms, and the electrons of the metal are free to move around. To zinc conduct electricity depends on the state of the compound if its solid it doesnâ€™t conduct electricity but when itâ€™s heated and molten then it can conduct electricity. Some things that people could do with their non-ecological energy sources it to take them to containers of used batteries, consume energy in an environmental way, use rechargeable batteries they can replace 300 batteries, avoid the use of batteries if its possible, do not throw hem on the garbage or on the street because their toxic metals will go to the atmosphere, do not bury them because they pollute the soil, do not burn them and avoid them to get into water.
Variables. Independent -Fruit used -Metal used -Metals distance from each other 2(inches) Dependent -Volts generated -Acidity of the fruit
1. Squeeze gently the lemon or the apple without breaking its skin so the liquid starts flowing inside it 2. Make holes in the lemon so we can put in the copper and zinc strips 3. Push copper and zinc strips inside the lemon 2 inches away from each other, (make sure they don't touch each other inside the lemon) 4. Connect one wire to the zinc 5. Connect another wire to the copper 6. Connect the two wires to the LED focus
i Reagents 3 lemons 2 green apples 5 copper strips 5 zinc strips 2 LED focus
ii Equipment 6 caiman wires 1 voltmeter
THE EXPERIMENT INSTRUCTIONS AND MATERIALS
Zn → Zn2+ + 2e2H++ 2e- → H2.
1 lemon/1 apple
1 apple/2 lemons
1 apple/3 lemons
2 apples/3 lemons
RESULT ANALYSIS We didn’t reach our goal because to light up a LED focus it’s needed to have 4.87 volts and the maximum volts we had was 4.38 the different circuits that we made are: a circuit with one lemon one strip of zinc and one strip of copper the volts generated were 0.78, in a circuit with one apple and the copper and zinc strips the volts went up to 1.01, if the circuits are combined the volts go up to 1.85 volts, if its added one lemon to that circuit the volts would go up to 2.76 volts, if the circuit would have one more lemon the volts would be 3.71 volts, if its added one more apple to the circuit the volts would be 4.38. With any circuit mentioned before the LED focus would be turned on because it’s missing 0.49 volts. If to the last
circuit its added one more apple or lemon it could be possible to light up the LED focus because it will reach the volts necessary to make it light up. If the circuit had some other fruit with a higher level of acidity it would be easier to light up the LED focus because it will reach the electricity needed in an easier and faster way because of its electrolytes. If the circuit would me made by magnesium instead of copper the circuit would conduct electricity easier because this metal allows electricity to flow through it easier, and it would have reached the voltage faster and with less fruits.
CONCLUSION & ACKNOWLEDGEMENTS
Fruits can make green electricity; our objective was not achieved because we planned on lighting a LED focus with different fruits but unfortunately, we didn’t reach the voltage necessary to light it up and we didn’t use enough acid for it to have a reaction that lights up our led focus. Also we tried to replace zinc with magnesium and we have higher chances that the LED focus will turn on because we reach a higher lever of voltage, but we didn’t had enough magnesium like to complete the circuit to reach the voltage necessary to light up a LED focus.
The authors would like to thank the Physics department for providing us a voltmeter and the Chemistry department for providing us copper and zinc strips. Also we would like to thank chemistry professor Ari Benjamin for his valuable help in the electro choice and his valuable opinion on this project. 7
"Tabla Acidez." Tabla Acidez. N.p., n.d. Web. 19 Nov. 2013. <http://www.vinodefruta.com/tabla_acid _ss.htm>. "Electrolytes." Electrolytes. N.p., 2011. Web. 19 Nov. 2013. <http://www.science.uwaterloo.ca/~cchi eh/cact/c120/electrolyte.html>. "Impacto Ambiental: Pilas." Impacto Ambiental: Pilas. N.p., n.d. Web. 19 Nov. 2013. <Impacto Ambiental: pilas>.