Dissociation and Ionization of Electrolytes

Arrhenius received the 1903 Nobel Prize in chemistry for his work on electrolytes. He found that a solution conducts electricity because the solute dissociates immediately upon dissolving into electrically charged particles (ions). The movement of these ions toward oppositely charged electrodes causes the solution to be a conductor. According to Arrhenius s theory, solutions that are relatively poor conductors contain electrolytes that are only partly dissociated. Arrhenius also believed that ions exist in solution whether or not an electric current is present. In other words, the electric current does not cause the formation of ions. Remember that positive ions are cations negative ions are anions. 

A simplified dissociation equation in which the water is omitted but understood to be present is 

Hydrated sodium and chloride bns. When sodium chbride dissolves in vvater, each Na and Cl ion becomes surrounded by vvater motecutes. 

Remember that sodium chloride exists in an aqueous solution as hydrated ions, not as NaCl units, even though the formula NaCl (or Na + Cl ) is often used in equations. 

The chemical reactions of salts in solution are the reactions of their ions. For example, when sodium chloride and silver nitrate react and form a precipitate of silver chloride, only the Ag and Cl ions participate in the reaction. The Na and NO3 remain as ions in solution  

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Svante Arrhenius, 1859-1927, was a Swedish chemist who won the 1905 Nobel Prize in chemistry for his theory of dissociation and ionization of electrolytes In solution. 

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