SLIDE 1: Electrochemistry is the science that involves chemical reactions caused by electricity.
SLIDE 2: Redox reactions are transfer of electrons caused byelectricity. It explains chemical reactions which are very usual in our daily life such a generation of power. Oxidation is the loss of electrons or an increase of oxidation number while reduction is the gainof electrons or a decrease of oxidation number. So, the oxidizing agent is the substance which gives oxygen or takes out hydrogen from another one. Some of the most common oxidising agents areHydrogen peroxide, Bromine or potassium dichromate.
SLIDE 3: There are two types of oxidation reduction reactions: Direct redox reaction and indirect redox reaction. The direct redox reaction is theprocess of oxidation and reduction of agents in direct contact. Cu(s) + 2 Ag+ (aq) ---> Cu2+ (aq) + 2 Ag(s)
SLIDE 4The indirect redox reactions occurs when is a transfer of electrons with a wire fromthe reducing agent to the oxidizing agent.
SLIDE 5: Voltaic cells are electrochemical cells that convert chemical Energy in chemical energy by spontaneous redox. We are using voltaic cells in ourdaily life. For example, when we use our car because it has a battery which it works with a group of cells connected together.
SLIDE 6: As I said before, in voltaic cells, is indispensable the use ofspontaneous redox to flow electricity. All the half reactions are given in half cells. The electrodes are connected by a wire and the electrolyte solutions are connected by the salt bridge. As aresult, we get an electrochemical cell. We can see that the oxidation is in the anode half cell: Zn (s) _____ Zn^2+ (aq) +2 e- . Then, the Zinc is the negative electron because it is oxidised.
On the otherside, the reduction is in the cathode half cell: Cu^2+ (aq)+ 2e- ____Cu(s). Then, the copper is the positive electrode.
So, the cell reaction through the salt bridge is: Zn (s) __Zn^2+ (aq) +2 e-...