An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. Electrically, such a solution is neutral.

An electrolyte is what is called an ionic conductor. The electrolytes are capable of conducting electric current, once dissolved in solution, due to the presence of positive and negative ions in the solution, derived from the dissociation and ionization of the electrolyte. Regarding the chemical nature, acids, bases, and salts are electrolytes. From the point of view of the state of aggregation, the electrolytes can be divided into:

  • electrolytic solutions (hydrochloric acid and sulfuric acid);
  • solid electrolytes (β-alumina, allotropic form of aluminum oxide);
  • ionic solids (sodium chloride, silver iodide and calcium fluoride);
  • molten salts (alkaline nitrates).

An electrolyte can be strong or weak; in a solution may be described as “concentrated“ if it has a high concentration of ions, or “diluted“ if it has a low concentration. A strong electrolyte is a solution/solute that completely, or almost completely, ionizes or dissociates in a solution. These ions are good conductors of electric current in the solution. A weak electrolyte is an electrolyte that is only partially dissociated in water.

Applications of electrolytes

Electrolytes are essential components of electrochemical cells (including galvanic cells and electrolytic cells), where they have the function of transporting the electric charge from one electrode to another. In an electrochemical cell, two electrolytic solutions can also be present, separated by a porous septum or a salt bridge.

The electrolytes are used inside particular capacitors, called electrolytic capacitors.

The electrolytes can also be used to carry out flocculation operations (used in wastewater treatment) and ion exchange (used in water softening and ion exchange chromatography operations).

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