How is generation of electricity from potato related to the theme science and technology for sustainable environmental improvement?

Answer 1

Using fruits and vegetables to produce electricity +++ My science project will try to prove that by inserting electrodes in lemons, Oranges, potatoes, carrots and salt water, there is a possibility that one or more of these items will produce electricity and light a small lamp. I need to know if anybody can help me in this experiment by giving me some information as to what is the best way of doing this experiment. Thalia B

6th grader making a science project . - Tarzana, California ----

+++ You are young to really understand much of this, Thalia, but the fruit or vegetable doesn't really produce the electricity, it just provides a conductive liquid that completes the circuit. To take it one step at a time, look at the diagram. As it is shown -- orange or no orange -- the bulb will light because there is a battery and a complete circuit. The current flows from the battery, through the blue wire, through the bulb, through the brown wire, through the left electrode, through the red wire, through the right electrode, and through the green wire back to the battery. Now, for the second step, if the Orange Juice is a conductive liquid (electrolyte), which it is, the red wire can be removed and the system should still work because electricity can flow from the left electrode through the juice to the right electrode, so we still have a complete circuit. Next, for the third step, you can remove the battery and connect the loose ends of the blue and green wires together. Now you have a complete circuit, but you don't have a battery anymore so the light goes out. Finally, make the electrodes out of two different metals (say copper and zinc) and the lamp will light again. This is because two different metals put into a conductive electrolyte actually comprise a battery. In fact, that's what any battery is: two different metals with a conductive solution between them. So it's not that the orange "produces" electricity, it is that copper plus zinc plus orange juice as the conductive electrolyte make a battery. In this case, the acidic juice allows a small amount of zinc and copper to dissolve in solution. But the zinc has a stronger propensity to go into solution so it drives the copper back out of solution. The net result is that copper dissolves from the copper electrode and deposits on the zinc electrode. Copper metal thus moves from the copper electrode to the zinc electrode (eventually completely coating it). Copper, like all metals (and all materials) has electrons. When the copper dissolves into solution it leaves some of its electrons behind on the copper electrode and dissolves into solution as a positively charged ion, but those electrons that don't travel through the solution with the copper ions, must travel to the zinc electrode through the wire. This movement of electrons is electricity. As I said, some of this will be over your head, but that's as simple as I can make it, and you can absorb what you can from it. The actual amount of electricity produced is very small and you will probably not be able to find even a penlight bulb that you can light with this little bit of electricity, but light emitting diodes (LEDs) require less electricity, so you may be able to light a small one. The liquid crystal displays on electronic calculators use even less electricity (almost none) so you will be able to operate that if you can find one and (with a parent or teacher's help) connect the orange battery in place of the built-in battery. From :- Rahul Panda , K.V. , Berhampur