Difference Between Electrolytes and Nonelectrolytes

Main Difference – Electrolytes vs Nonelectrolytes

Chemical compounds can be divided into two categories according to their ability to conduct electricity through their aqueous solution. These two categories are electrolytes and nonelectrolytes. Electrolytes are chemical compounds that can dissolve in water forming ions. These ions can conduct electricity through the solution. Nonelectrolytes are chemical compounds that do not conduct electricity when dissolved in water. This is because they do not form ions when dissolved in water. The main difference between electrolytes and nonelectrolytes is that electrolytes can get ionized when dissolved in water whereas nonelectrolytes cannot get ionized when dissolved in water.

Key Areas Covered

1. What are Electrolytes
      – Definition, Explanation of Electrolytic Properties with Examples
2. What are Nonelectrolytes
      – Definition, Explanation of General Properties with Examples
3. What is the Difference Between Electrolytes and Nonelectrolytes
      – Comparison of Key Differences

Key Terms: Anions, Cations, Covalent Compounds, Electrolytes, Ionic Compounds, Ionization, Nonelectrolytes

What are Electrolytes

Electrolytes are chemical compounds that can break down into ions when dissolved in water. These ions can conduct electricity through this aqueous solution. In order to break down into its ions, the electrolyte should be an ionic compound. Ionic compounds are made out of cations and anions.

When dissolved in water, these ionic compounds can form aqueous cations and anions. These ions are dispersed uniformly throughout the solution. Then the solution is electrically neutral. If an electrical current is provided to this solution from outside, the ions in the solution start to move. Cations move to the electrode where electron density is high. Anions tend to move to the other electrode. This movement of ions makes an electric current through the solution.

There are two types of electrolytes: strong electrolytes and weak electrolytes. Strong electrolytes completely ionize into its ions. There are no neutral molecules in the aqueous solution of a strong electrolyte. Weak electrolytes do not completely ionize into its ions. Therefore, there are also some neutral molecules present in the solution.

Figure 1: Electrolytes are used in Electrochemical Techniques

Strong acids and strong bases are strong electrolytes since they can completely ionize in water. A compound should not necessarily dissolve completely in water in order to be considered as a strong electrolyte. Some compounds partially dissolve in water but yet they are strong electrolytes. For example, strontium hydroxide, Sr(OH)₂ is partially dissolved in water. But it is a strong electrolyte since the amount that is dissolved is completely ionized. Moreover, salts such as NaCl, MgCl₂ are also strong electrolytes since they are ionic compounds with a high degree of ionic characteristics.

Weak acids and weak bases are considered as weak electrolytes. This is because these compounds partially dissociate into ions. Most nitrogen-containing compounds are weak electrolytes. Water is also considered as a weak electrolyte. The water molecules are in equilibrium with hydroxyl ions and hydronium ions.

What are Nonelectrolytes

Nonelectrolytes are chemical compounds whose aqueous solutions cannot conduct electricity through the solution. These compounds do not exist in ionic form. Most nonelectrolytes are covalent compounds. When dissolved in water, these compounds do not form ions at all.

Figure 2: Sugar can be completely dissolved in water, but it is not an electrolyte.

Most carbon compounds such as hydrocarbons are nonelectrolytes since because these compounds cannot dissolve in water. Some compounds such as glucose can dissolve in water, but do not ionize. An aqueous solution of glucose is composed of glucose molecules. Therefore, sugars, fat, and alcohols are nonelectrolytes. Typically, nonelectrolytes are nonpolar compounds.

Difference Between Electrolytes and Nonelectrolytes

Definition

Electrolytes:  Electrolytes are chemical compounds that can break down into ions when dissolved in water.

Nonelectrolytes: Nonelectrolytes are chemical compounds whose aqueous solutions cannot conduct electricity through the solution.

Electrical Conductivity

Electrolytes: Electrolytes can conduct electricity through their aqueous solutions.

Nonelectrolytes: Nonelectrolytes cannot conduct electricity through their aqueous solutions.

Chemical Bonding

Electrolytes: Electrolytes are composed of ionic bonds.

Nonelectrolytes: Nonelectrolytes are composed of covalent bonds.

Compounds

Electrolytes: Electrolytes are ionic compounds. Acids, base and salts are electrolytes.

Nonelectrolytes: Nonelectrolytes are covalent compounds. Carbon-containing compounds, fat and sugar are nonelectrolytes.

Types

Electrolytes: Electrolytes can be found as strong electrolytes and weak electrolytes.

Nonelectrolytes: Nonelectrolytes cannot be found as water-soluble compounds and water-insoluble compounds.

Conclusion

Electrolytes and nonelectrolytes are chemical compounds that are named as such according to the ability or the inability to conduct electricity through their aqueous solutions. This ability depends on the ionization of the compound. In other words, the compound should be broken down into ions in order to conduct electricity through ions. The main difference between electrolytes and nonelectrolytes is that electrolytes can get ionized when dissolved in water whereas nonelectrolytes cannot get ionized when dissolved in water.

Image Courtesy:

1. “Chemical Principles Fig 1.9” By .The original uploader was Elo 1219 at English Wikibooks – Transferred from en.wikibooks to Commons. (CC BY 3.0) via Commons Wikimedia
2. “Spoon Sugar Solution with Glass” By APN MJM – Own work (CC BY-SA 3.0) via Commons Wikimedia