An Overview of Strong and Weak Electrolytes

An electrolyte is a medium that contains ions and conducts electricity through the movement of ions but not electrons. Most soluble salts, acids, and bases dissolved in a polar solvent, such as water, fall into this category. When a substance dissolves, it splits into cations and anions, which are evenly dispersed throughout the solvent. There are other solid-state electrolytes. The term electrolyte is used in medicine and chemistry to describe a dissolved material.

This includes the majority of soluble salts, acids, and bases dissolved in a polar solvent like water. When a substance dissolves, it separates into cations and anions that are distributed uniformly throughout the solvent. 

Such a solution is electrically neutral. When an electric potential is introduced to such a solution, the cations are pulled to the electrode with the most electrons, while the anions are drawn to the electrode with the least electrons. A current is the movement of anions and cations in opposite directions within a solution. Some gases, like hydrogen chloride (HCl), can act as electrolytes when they are exposed to high temperatures or low pressures. Electrolyte solutions can also emerge from the breakdown of biological (e.g., DNA, polypeptides) or synthetic polymers with charged functional groups, known as “polyelectrolytes.” In solution or in the melt, a substance that dissociates into ions gains the ability to conduct electricity.

The essential components of salt dissociate when they are dissolved in a solvent such as water due to thermodynamic interactions between the solvent and solute molecules, a process known as “solvation.” 

Electrolysis is the process of disintegrating a molten or watery substance by putting an electric current through it. The main components of the electrolysis process are electrodes, electrolytes, and salt solution. The electrolyte is crucial to the process of electrolyte formation.

Classification Of Electrolyte

As chemists, we need to be able to immediately recognize which of these classifications a formula like HCl or NaOH belongs to, because we need to know what we’re working with (ions or compounds) while working with chemicals. 

Based on the degree of ionization, the electrolytes are divided into two groups.: 

• Strong electrolytes – Strong electrolytes are electrolytes that are completely dissociated into ions in solution.

Unionized molecules (electrolytes) can be overlooked because they are present in such minute concentrations. They’re also useless for studying strong electrolyte ionization constants. Strong electrolyte ionization equations do not use double-headed arrows, unlike weak electrolyte ionization equations.

HCl + H₂O → H₃O⁺ + Cl^–

HNO₃ + H₂O → H₃O⁺ + NO₃^–

Examples of strong and weak electrolytes-

• Strong acid- eg, HCl, HI, HBr, HNO_3, HNO_3, HClO₃
• Strong bases- eg, NaOH, KOH, LiOH, Ba (OH)₂ 
• Salts- eg NaCl, KBr, MgCl_2, and many more

• Weak electrolytes- When a current is passed through a substance, it does not dissociate entirely into ions.

Weak electrolyte molecules in a solution are in equilibrium with their ions. As a result, the equation for ionization of weak electrolytes is shown with double-headed arrows, implying that the reaction is reversible, as in-

NH₃ + H₂O ⇌ NH₄⁺+ OH^–

CH₃COOH + H₂O ⇌ H₃O⁺+ CH₃COO^–

Examples of weak electrolytes-

• Weak acids- HF, H₂CO₃
• Weak bases- NH₃

Difference Between Strong and Weak Electrolytes

Weak Electrolytes

• In an aqueous solution, a weak electrolyte is one that does not entirely dissociate. In water, weak electrolytes only partially ionize (usually 1 percent to 10 percent).
• In a solution or molten state, these chemicals are partly ionized. Ions and un-dissociated molecules are present in these electrolytes.
• Even at higher concentrations, interionic interactions are weak.
• Ostwald’s dilution law is applicable.
• At moderate concentrations, weak electrolytes do not entirely dissociate.
• They have a low conductivity of electricity.
• Acids, alkalis, and salts like oxalic acid, formic acid, acetic acid, ammonium hydroxide, calcium hydroxide are all examples of weak electrolytes.
• Acetic acid (the acid found in vinegar), for example, is exceedingly water soluble. However, rather than its ionized form, ethanoate, the majority of the acetic acid remains intact as its original molecule (CH3COO-). Acetic acid dissolves in water and ionises to produce ethanoate and the hydronium ion, but the equilibrium is to the left (reactants are favored).  In other words, when ethanoate and hydronium are formed, they quickly decompose into acetic acid and water.

CH₃COOH + H₂O ⇆ CH₃COO^– + H₃O⁺

Strong Electrolytes

• A strong electrolyte is a solution/solute that ionizes or dissociates completely or nearly completely in a solution. In the solution, these ions are good conductors of electric current. 
• In solution or molten form, these electrolytes are totally ionized. As a result, these compounds only contain ions in a liquid or molten form.
• At moderate quantities, strong electrolytes totally dissociate.
• At high concentrations, there are strong interionic interactions.
• Ostwald’s dilution law is not applicable.
• Acids, alkalis, and salts like sodium chloride, potassium chloride, sodium hydroxide, potassium hydroxide, sodium nitrate, and lead sulfate, are all examples of strong electrolytes.

Conclusion

Electrolytes are one of the most important components of electrochemical cells in science. Apart from that, they play an important role in the human body by maintaining electrolyte balance, which is necessary for the body’s proper functioning.