In the Debye-Hückel theory, what is the primary interaction considered?

In the context of the Debye-Hückel theory, the primary interaction considered is Coulombic interactions. This theory addresses the behavior of electrolyte solutions by focusing on the electrostatic forces between charged particles. It posits that ions in a solution interact through a long-range Coulomb potential that is inversely proportional to the distance between them. This means that the attractive and repulsive forces due to the charges of the ions significantly influence properties like activity coefficients and, subsequently, the thermodynamic behavior of the solution.

Coulombic interactions play a key role in defining how ions behave in a solution, particularly at low concentrations where the ionic interactions are most significant. Debye-Hückel theory effectively models these interactions by incorporating the concept of ionic strength, which quantifies the total ion concentration in solution, influencing the overall electrostatic potential experienced by each ion. This approach is crucial for understanding the non-ideal behavior of electrolytes in solution compared to ideal solutions, where such interactions are not considered.

In assessing the other interactions listed — Van der Waals forces, covalent bonding, and hydrogen bonding — it's clear that they do not address the charged nature of ions and their behavior in solutions, making them less relevant to the focus of Debye-H