Electric dissociation plays a huge role in our lives, though we do not usually think about it.It is this phenomenon related electrical conductivity of salts, acids and bases in a liquid medium.Since the first heart rhythm caused by a "living" electricity in the human body, eighty percent of which consists of liquids, to cars, mobile phones and players, batteries that are inherently electrochemical batteries - everywhere around us invisibly present electric dissociation.
in giant vats exuding toxic fumes from melted at high temperatures is obtained by electrolysis of bauxite "winged" metal - aluminum.All objects around us, from the chrome-plated radiator covers up earrings in your ears, ever faced with solutions or molten salts, and hence the phenomenon.Not for nothing is studied electrical dissociation whole branch of science - electrochemistry.
When dissolving liquid solvent molecules enter into a chemical bond with the molecules of the solute to form solvates.In aqueous solution, the dissociation most susceptible salts, acids and bases.As a result of this process, the solute molecules may dissociate into ions.For example, an aqueous solvent under the influence of ions of Na + and CI-, located in an ionic crystal NaCI, moving in a solvent in solvated as already new (hydrated) particles.
This phenomenon, which represents essentially a process of complete or partial collapse of the substance dissolved ions as a result of exposure to the solvent, and is called "electric dissociation."This process is extremely important for electrochemistry.Of great importance is the fact that the dissociation of the complex multicomponent systems is characterized by the occurrence of a step.When this phenomenon is observed as a sharp increase in the number of ions in solution, which is distinguished by electroless, electrolytic substance.
During electrolysis ions have a clear direction of motion of a particle with a positive charge (cations) - to the negatively charged electrode called the cathode, and the positive ions (anions) - to the anode electrode of opposite charge, where they are discharged.Cations are restored, and the anions are oxidized.Therefore, the dissociation is a reversible process.
One of the fundamental characteristics of this electrochemical process is the degree of electrolytic dissociation, which is expressed by the ratio of hydrated particles to the total number of molecules of the dissolved substance.The higher the number, the stronger the electrolyte is given substance.On this basis, all substances are divided into weak, medium strength and strong electrolytes.
degree of dissociation depends on the following factors: a) the nature of the solute;b) the nature of the solvent, its dielectric constant and polarity;c) concentration of the solution (the lower the score, the greater the degree of dissociation);d) the temperature of the dissolution medium.For example, the dissociation of acetic acid can be expressed by the following formula:
CH3COOH + H + SN3SOO-
strong electrolytes are dissociated virtually irreversibly because their aqueous solution remains non-hydrated initial molecules and ions.It should also be added that the process of dissociation affects all substances with ionic and covalent polar type of chemical bonds.The theory of electrolytic dissociation formulated the famous Swedish chemist and physicist Svante Arrhenius in 1887.
