Hello friends today I am going to discuss about electrode potential. Before discussing electrode potential first I will discuss about cell. What is cell? Cell is a unit or it is a device which converts physical or chemical energy into the form of electrical energy. So cell is made up of two electrode each electrode is known as half cell so there are example of many half cells like hydrogen half cell zinc half cell copper half cell etc So these are some example of half cells.
This one is hydrogen half cell. This one is zinc half cell. This one is copper half cell. This one is iron half cell and your last one is chlorine half cell.
So these are the examples of some half electrodes now coming to the term electrode potential So what is electrode potential? electrode potential is potential difference between two half cells For example, if we are taking hydrogen electrode as an extended then we will compare other electrode with reference to hydrogen electrode and whatever difference between potential of both electrode will be known as electrode potential. So here I have taken hydrogen electrode as a standard and electrode potential for hydrogen will be 0.00 volt and zinc electrode is taken as a sample electrode. So now difference between the potential of this hydrogen and zinc will be the electrode potential of this example. Now I will draw a block diagram for hydrogen and zinc electrode for better understanding.
So, this is the block diagram of hydrogen half cell. This acts as a reference electrode. So, here 1 molar H plus sign is there.
How you will prepare 1 molar H plus? If you will prepare 1 molar HCl then automatically it will contain 1 molar H plus. And from here hydrogen gas is supplied.
So, hydrogen gas will go to the solution. And in this solution platinum wire will be attached because hydrogen gas will not be able to conduct the electricity now coming to the next half cell which is zinc half cell this is block diagram of zinc half cell here one molar Zn2 plus ion is there how you will prepare one molar ZnSO4 contains one molar Zn2 plus ion and here one zinc rod is immersed in the solution and here no platinum wire is required because zinc can conduct the electricity now we will attach these wires in the middle part of Both the electrode one galvanometer will be there and here galvanometer is able to measure the electrode potential or difference between the potential of hydrogen electrode and Zinc electrode so what will be the potential difference between hydrogen and zinc electrode so here hydrogen electrode is Hydrogen electrode is showing 0.00 electrode potential and as compared to this hydrogen electrode because it is reference electrode zinc electrode will show the electrode potential of minus 0.76 this minus 0.76 is denoted in the form of voltage this is reduction potential if it will be oxidation potential then it will be Zn Zn2 plus and it will be plus 0.76 volt ok so this is the electrode potential of zinc ok there are other metals which are showing various electrode potential and that is known as electrochemical series so here i will write important metals with their electrode potential so first one is cerium it is showing plus 1.61 volt Second one is gold it is showing plus 1.50 volt Third one is chlorine it is showing plus 1.36 volt Fourth one is copper it is showing plus 0.34 volt 5th one is hydrogen it is showing 0.00 volt 6th one is iron it is showing minus 0.44 volt 7th one is zinc it is showing minus 0.76 volt Eighth one is aluminum it is showing minus 1.66 volt. Ninth one is sodium it is showing minus 1.71 volt. Tenth and last one is lithium it is showing minus 3.04 volt.
So, these are the electrode potential of some selected samples and this is known as electrochemical series. So, this is the details about electrode potential. Thank you.