How to Classify Electrolytes?

An electrolyte is a substance that conducts electric current by dissociating into positively and negatively charged ions, which migrate to and discharge at the negative and positive terminals (cathode and anode, respectively) of an electric circuit.

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. 

Electrolytes aren’t all substances that dissolve in water. Sugar, for example, dissolves swiftly in water but only as molecules, not as ions. Sugar is a compound that does not have an electrolyte. Because it ionized, water is a weak electrolyte.

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.” The dissociation reaction shows how table salt (sodium chloride, NaCl) dissolves in water and dissociates into its component ions.

NaCl (s) → Na⁺(aq) + Cl^– (aq)

Basics Of Classifying Electrolytes

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. 

For example, we need to know that a bottle labeled “NaCN” (salt) actually contains no NaCN but rather Na+ and CN–, or that a bottle labeled “HCN” (weak acid) contains mostly HCN but also a little amount of H+ and CN–.

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

• Strong electrolytes – Electrolytes that are entirely dissociated into ions in solution are known as strong electrolytes.

Because unionized molecules (electrolytes) are present in such small amounts, they can be neglected. They also have no application in the study of strong electrolyte ionization constants. Unlike weak electrolyte ionization equations, strong electrolyte ionization equations do not use double-headed arrows.

HCl + H₂O → H₃O⁺ + Cl^–

HNO₃ + H₂O → H₃O⁺ + NO₃^–

In solution or molten form, these electrolytes are totally ionized. As a result, these compounds only contain ions in a liquid or molten form and also have a high electricity conductivity.

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

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

NH₃ + H₂O ⇌ NH₄⁺+ OH^–

CH₃COOH + H₂O ⇌ H₃O⁺+ CH₃COO^–

In a solution or molten state, these chemicals are partly ionized. Ions and un-dissociated molecules are present in these electrolytes. They have a low conductivity of electricity.

Electrolytes Are Categorized In Six Steps

So, based on their formula, how do we categorize compounds?

The following is an example of a useful approach:

Step 1: Is it one of the strong acids?

Step 2: Is it in the Metal (OH)n format? It’s then a solid foundation.

Step 3: Is it Metal(X)n in shape? It’s a salt after that.

Step 4: Is there a ‘H’ in the formula? It’s most likely a low-concentration acid.

Step 5: Is there a nitrogen atom in it? It’s possible that the foundation isn’t strong enough.

Step 6: Isn’t it true that none of them apply to you? A nonelectrolyte is a term used to describe a substance that is neither electrolyte nor electrolyte

It’s important to remember that the conductivity of an electrolyte solution is proportional to the electrolyte’s strength. This means that the bigger the ionic concentration of the solution, the higher the conduction will be. So, by applying a voltage to electrodes submerged in a solution and measuring the electric current or viewing the brightness of a light bulb included in the circuit, one can determine the ionic concentration quantitatively (such light is used in spectroscopic techniques to quantify data).

Examples Of Strong And Weak Electrolytes

Strong 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, MgCl₂ and many more.

Weak electrolytes

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

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.