Non-Electrolytes

Definition

Non-electrolytes are substances that do not dissociate into ions when dissolved in water or other solvents. They are molecules that do not conduct electricity in aqueous solutions, in contrast to electrolytes which do dissociate into charged particles.

5 Must Know Facts For Your Next Test

1. Non-electrolytes do not produce ions in solution, and therefore do not contribute to the solution's electrical conductivity.
2. Common examples of non-electrolytes include sugar (sucrose), alcohol (ethanol), and organic compounds like urea and glucose.
3. The lack of dissociation into ions means non-electrolytes do not affect the pH of the solution, unlike electrolytes which can alter the hydrogen ion concentration.
4. Non-electrolytes typically have covalent bonds within their molecular structure, which prevents the formation of free-moving ions.
5. The solubility of non-electrolytes in water is determined by the presence of polar functional groups that can form hydrogen bonds with water molecules.

Review Questions

• Explain the key difference between electrolytes and non-electrolytes in terms of their behavior in aqueous solutions.
  • The primary distinction between electrolytes and non-electrolytes is their ability to dissociate into ions when dissolved in water or other solvents. Electrolytes are substances that can break apart into charged particles, or ions, which can then conduct electricity in the solution. In contrast, non-electrolytes are molecules that remain intact and do not form ions, and therefore do not contribute to the electrical conductivity of the solution.
• Describe the relationship between the molecular structure of non-electrolytes and their inability to dissociate into ions.
  • The molecular structure of non-electrolytes, typically characterized by covalent bonds, prevents them from dissociating into ions when dissolved in water or other solvents. The atoms within non-electrolyte molecules are held together by strong covalent bonds, which do not allow the molecules to break apart into charged particles. This lack of ion formation is what distinguishes non-electrolytes from electrolytes, which can dissociate due to the presence of ionic bonds in their molecular structure.
• Analyze how the solubility of non-electrolytes in water is influenced by the presence of polar functional groups in their molecular structure.
  • The solubility of non-electrolytes in water is largely determined by the presence of polar functional groups within their molecular structure. These polar groups, such as hydroxyl (-OH) or carbonyl (C=O) groups, can form hydrogen bonds with water molecules, allowing the non-electrolyte to dissolve and create a homogeneous solution. The ability of non-electrolytes to participate in hydrogen bonding with water facilitates their solubility, in contrast to non-polar, non-electrolyte molecules that tend to be less soluble in water. This relationship between molecular structure and solubility is an important factor in understanding the behavior of non-electrolytes in aqueous environments.

Related terms

Electrolytes:

Substances that dissociate into ions when dissolved in water or other solvents, and are therefore able to conduct electricity in aqueous solutions.

Molecular Compounds:

Chemical compounds in which the atoms are held together by covalent bonds, forming discrete molecules rather than a continuous network of ions.

Solubility:

The ability of a substance to dissolve in a solvent, forming a homogeneous solution.