An electrolyte is a substance that forms an electrically conductive solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which are uniformly distributed throughout the solvent. Such a solution is electrically neutral.
An electrolyte is what is known as an ionic conductor. The electrolytes, once dissolved in solution, are capable of conducting an electric current due to the presence of positive and negative ions in the solution, which result from the dissociation and ionization of the electrolyte. In terms of chemical nature, acids, bases, and salts are electrolytes. From the point of view of the state of aggregation, electrolytes can be divided into:
- electrolytic solutions (hydrochloric acid and sulphuric 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 solution it can be described as “concentrated” if it has a high concentration of ions, or “dilute” if it has a low concentration. A strong electrolyte is a solution/solute that ionizes or dissociates completely or almost completely in a solution. These ions are good conductors of electrical current in the solution. A weak electrolyte is one that only partially dissociates in water.
Applications of electrolytes
Electrolytes are essential components of electrochemical cells (including galvanic cells and electrolytic cells), where their function is to transport the electric charge from one electrode to another. An electrochemical cell may also contain two electrolyte solutions separated by a porous septum or salt bridge.
The electrolytes are used in special capacitors called electrolytic capacitors.
The electrolytes can also be used to perform flocculation (used in wastewater treatment) and ion exchange (used in water softening and ion exchange chromatography).