CUrrent is everywhere

Different ways to create electricity from household things

Submitted to: Sir Abdul Majid

Submitted By:

Luqman Saleem 11011510-099

Ibn-e-Abbas 11011510-096

Zahid Ali 11011510-079

BS Physics 8th Section B

University of Gujrat

Current is everywhereAbstractWe normally think that we are running out of energy but there is energy everywhere around us we just need to learn how to use it. Here we are explaining how to get energy form some simple household things. You just need to arrange these things in a specific order and you can recharge your mobile phone with it.

IntroductionWhat is current? How a bulb light up? How a mobile recharge itself with current? Current is simply flow of electron. These electrons when flow in a circuit through some specific electrical components makes the whole new technology. So for everything to work we need to flow the electrons. Now the problem is how to make electrons flow? This is quite tricky and sometime very difficult. The electricity we use in our homes is also the flow of electrons form power grid to our home these electrons are powered by a mechanical energy this mechanical energy is changed into electrical energy. So we have used a basic law that Energy cannot be created or destroyed, but it can be saved in various forms. One way to store it is in the form of chemical energy in a battery. When connected in a circuit, a battery can produce electricity. Here we will use different type of energy to change them into electrical energy and form a battery. But what is a battery? A battery has two ends a positive terminal (cathode) and a negative terminal (anode). If you connect the two terminals with wire, a circuit is formed. Electrons will flow through the wire and a current of electricity is produced. Inside the battery, a reaction between chemicals take place. But the reaction takes place only if there is a flow of electrons. Batteries can be stored for a long time and still work because the chemical process doesn't start until the electrons flow from the negative to the positive terminals through a circuit.

There are different type of simple energy conversation to make a battery. For example:

Water battery Lemon battery Potato battery

Water batteryThe concept behind it is to make a galvanic cell that works on either a salt bridge or a sour bridge. In this case it's a salt bridge, but you could try using plants or wine (instead of water) to create the same effect. You can make a battery from these things that are easily available

Redstone Bluestone Water

Cables 6 plastic bottles 6 pieces of copper 6 pieces of zinc

Fill the bottles with water and connect the anodes and cathodes as anode is Zinc plate and cathode is Copper plate with cables. Now put these plates in bottle so that there is one zinc and one copper plate in every bottle. The remaining two end of wires will be your output points. Now put Redstone in one bottle and Bluestone in other bottle so that there are three redstone and 3 bluestone bottles. It’s done. You have created battery. Each bottle will produce around 2 volts.

Connect your mobile phone date cable to the output of this battery and your mobile will start recharging.

WorkingThis is simple a galvanic cell in which we have used ZnSO4 and CuSO4 to get electricity from charge transformation phenomena. Before explaining we should know about reduction and oxidation reactions. Many difinitions can be given to oxidation and reduction reactions. In terms of electrochemistry, the following definition is most appropriate, because it let us see how the electrons perform their roles in the chemistry of batteries.

Loss of electrons is oxidation, and gain of electrons is reduction.

Oxidation and reduction reactions cannot be carried out separately. They have to appear together in a chemical reaction. Thus oxidation and reduction reactions are often called redox reactions. In terms of redox reactions, a reducing agent and an oxidizing agent form a redox couple as they undergo the reaction:

Oxidant + n e- ----> Reductant

Reducant ----> Oxidant + n e-

An oxidant is an oxidizing reagent, and a reductant is a reducing agent.

As an introduction to electrochemistry let us take a look of a simple Voltaic cell or a galvanic cell. When a stick of zinc (Zn) is inserted in a salt solution, there is a tendency for Zn to lose electron according to the reaction,

Zn = Zn2+ + 2 e-

The arrangement of a Zn electrode in a solution containing Zn2+ ions is a half cell, which is usually represented by the notation:

Zn | Zn2+

Zinc metal and Zn2+ ion form a redox couple, Zn2+ being the oxidant, and Zn the reductant. The same notation was used to designate a redox couple earlier. Similarly, when a stick of copper (Cu) is inserted in a copper salt solution, there is also a tendency for Cu to lose electron according to the reaction,

Cu = Cu2+ + 2 e-

This is another half cell or redox couple: Cu | Cu2+

However, the tendency for Zn to lose electron is stronger than that for copper. When the two cells are connected by a salt bridge and an electric conductor as shown to form a closed circuit for electrons and ions to flow, copper ions (Cu2+) actually gains electron to become copper metal. The reaction and the redox couple are respectively represented below

Cu2+ + 2 e- = Cu Cu2+ | Cu

This arrangement is called a galvanic cell or battery as shown here. In a text form, this battery is represented by,

Zn | Zn2+ || Cu2+ | Cu

in which the two vertical lines ( || ) represent a salt bridge, and a single vertical line ( | ) represents the boundary between the two phases (metal and solution). Electrons flow through the electric conductors connecting the electrodes and ions flow through the salt bridge. When

[Zn2+] = [Cu2+] = 1.0 M,

A battery is a package of one or more galvanic cells used for the production and storage of electric energy. The simplest battery consists of two half cells, a reduction half cell and an oxidation half cell. The overall reaction of the galvanic cell is

Zn + Cu2+ = Zn2+ + Cu

Note that this redox reaction does not involve oxygen at all. For a review, note the following:

Oxidant + n e- = Reductant

Example: Cu2+ + 2 e-= Cu

Cu2+ is the oxidizing agent and Cu the reducing agent.

Reductant = n e- + Oxidant

Example: Zn = Zn2+ + 2 e-

Zn is the reducing agent, and Zn2+ the oxidizing agent.

Theoretically, any redox couple may form a half cell, and any two half cells may combine to give a battery but we have considerable technical difficulty in making some couples into a half cell.

Lemon BatteryA very simple battery that uses a lemon that has two different metallic objects inserted into it, for example a galvanized nail and a copper coin or wire. The copper serves as the positive electrode or cathode and the galvanized (zinc coated) nail as the electron-producing negative electrode or anode. These two objects work as electrodes, causing an electrochemical reaction which generates a small potential difference.

Since copper (Cu) atoms attract electrons more than zinc (Zn) atoms, if you place a piece of copper and a piece of zinc in contact with each other, electrons will pass from the zinc to the copper. As the electrons concentrate on the copper they will repel each other and stop the flow of electrons from zinc to copper. On the other hand, if you put strips of zinc and copper in a conductive solution, and connect them externally with a wire, the reactions between the electrodes and the solution will allow the electrons to flow continuously through the wire.

A lemon battery is made with a lemon and two metallic electrodes of different metals such as a copper penny or wire and a galvanized (zinc coated) nail. The energy for the battery does not come from the lemon, but rather the chemical change in zinc (or other metal). The zinc is oxidized inside the lemon, exchanging some of its electrons in order to reach a lower energy state, and the energy released provides the power. The lemon merely provides an environment where this can happen, but they are not used up in the process. Assuming that zinc and copper electrodes are used (such as a copper coin and a zinc plated nail) then a single lemon could generate approximately 0.9 Volts.

WorkingIn a lemon battery, both oxidation (loss of electrons) and reduction (gain of electrons) occur. This battery is similar to the original "simple voltaic cells" invented by Alessandro Volta (see below). At the anode, metallic zinc is oxidized, and enters the acidic solution as Zn2+ ions:

Zn ----> Zn2+ + 2 e-

At the copper cathode, hydrogen ions (solvated protons from the acidic solution in the lemon) are reduced to form molecular hydrogen:

2H++ 2e- ----> H2

What makes the electrons move? When you let go of a ball you are holding it falls to the ground because the Earth's gravitational field pulls the ball down. In a similar way charged particles such as electrons need to have work done to move them from one point to another. The amount of work per unit of charge is called is called the electric potential difference between the two points. The unit of potential difference is called the volt. The potential difference between the cathode and anode are set up from the chemical reaction. Inside the battery electrons are pushed by the chemical reaction toward the positive end creating a potential difference. It is this potential difference that drives the electrons through the wire. Potential difference can be positive or negative, likened to gravitational energy, moving up a hill or down a hill. In a battery the flow of electrons is downhill... electrons can flow uphill as in the case of a battery charger.

Why don't electrons just move from anode to cathode inside the battery? The electrolyte in the battery keeps lone electrons from going straight from the anode to the cathode within the battery. When the terminals are connected with a conductive wire, electrons can easily flow from anode to cathode.

What direction do electrons move in the wire? Electrons are negatively charged, so they will be attracted to the positive end of a battery and repelled by the negative end. When the battery is hooked up to a device that lets the electrons flow through it, they flow from negative (anode) to positive (cathode) terminal.

Potato BatteryWe can also get energy by using potato instead of lemon in the same circuit we used for lemon arrangement as we need

Zinc electrode Copper electrode Potatoes Wires

To make a battery that can recharge a mobile or light up LED. Some scientists have actually researched potatoes as a practical form of power. While many different plants can serve as batteries, potatoes are especially durable due to their high starch content. They do not rot easily or attract pests to the same degree as fruits and other alternatives. Cooking potatoes reduces their electrical resistance and actually makes them much more powerful as batteries.

WorkingPotato batteries require two different metal electrodes with different electrical qualities to work. The most common materials are zinc and copper. The acids in the potato react with the metals, creating an electron imbalance at each electrode. Because it keeps the ions formed by the reaction separate, but conducts electricity via its water and electrolytes, the reaction forces the electrons in the copper electrode to move. This movement of electrons is an electric current and is sufficient to power small devices.

The potato has a mild phosphoric acid content H3PO4

Reduction at Cu (copper) electrode:

2H+ + 2e- ----> H2 (gas)

Oxidation at Zn (zinc) electrode:

Zn ----> Zn+2 + 2e-

The H3PO4 acid puts the hydrogen ions in solution. So basically, the phosphoric acid in the potato acts like the acetic acid (vinegar).

Prepared By:

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