Electrolytes are substances that form electrically conducting solutions when they are dissolved in polar solvents (the most notable of which being water). Typically, electrolytes are ionic salts that dissociate into their constituent ions when dissolved in water. These charged ions (which get uniformly distributed across the solvent) are responsible for the increased electrical conductivity of the electrolyte solution. It is important to note that the electrolyte solution itself is electrically neutral. The introduction of a potential difference causes the migration of the positively charged cations to the electron-rich terminal and the migration of negatively charged anions to the electron-deficient terminal. This movement of ions results in the generation of an electric current. Common examples of electrolytes include sodium chloride, potassium chloride, nitric acid, perchloric acid, sodium hydroxide, and calcium hydroxide. Some important concepts related to electrolytes are detailed in this article.
How are Electrolytes Formed?
When an electrolyte is dissolved into a polar solvent, it dissociates into its constituent ions as a result of the thermodynamic interactions between the molecules of the solute (which is the electrolyte in this scenario) and the molecules of the solvent (which are polar). This process is commonly referred to as solvation. For example, when crystals of sodium chloride (common salt) are dissolved in water, they dissociate into sodium cations and chloride anions. These ions increase the electrical conductivity of the water. Thus, sodium chloride can be considered as an electrolyte that undergoes solvation when dissolved in water to form an electrolyte solution.
It is also possible for the molecules of the electrolyte to react with the water molecules to form hydroxide ions and hydronium ions. For example, when carbon dioxide is dissolved in water, small quantities of hydronium ions, hydrogen carbonate ions, and carbonate ions are formed.
Importance of Electrolytes
Sodium and potassium are vital electrolytes in the physiologies of human beings and other mammals. Sodium is the primary electrolyte that is found in extracellular fluid whereas potassium is the primary electrolyte in intracellular fluids. It can be noted that both potassium and sodium ions play a crucial role in the regulation of fluid balance and in the control of blood pressure. These ions are also used in oral rehydration solutions for the treatment of electrolyte deficiency, which can be brought on by excessive exercising, excessive consumption of alcohol, diaphoresis, starvation, or vomiting. Electrolytes can be administered both orally and intravenously in such situations.
Uses of Electrolytes
- Electrolytes are used in batteries where they complete the circuit and facilitate the flow of electrons.
- They are also used in some types of fuel cells where they help keep the oxygen gas separated from the hydrogen gas.
- Another important application of electrolytes is in electrolytic capacitors. Here, electrolytes are employed to produce a very thin insulating coating.
- When a glass is heated and softened, it is usually stored in the molten state with the passage of a large current through it.
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