How can a solvent dissolve a solute?

Before we start giving out examples, let define a two terms.

The solute is the substance that gets broken down. The solvent is the substance that breaks the solute down.

An example of this is the water (universal solvent) that dissolve salt (the solute). When mixing water with salt, you no longer see the salt particles anymore, which is a homogeneous mixture. A homogeneous mixture is a mixture made up of particles that are uniformly distributed meaning that they look the same (example: apple sauce)

A solvent dissolves a solute through the process of solvation (or dissolution), which involves breaking the intermolecular bonds in the solute and the solvent, and then forming new interactions between the solute and solvent molecules. This process can be described in three key steps:

1. Separation of solute particles: Energy is used to overcome the intermolecular forces holding the solute particles together in a solid or liquid. This energy is supplied by the interaction between the solute and solvent molecules.

2. Separation of solvent molecules: Similarly, energy is used to overcome the forces between solvent molecules to make space for the solute particles. This again is facilitated by the attraction between solute and solvent.

3. Formation of solute-solvent interactions: New interactions are formed between the solute and solvent molecules, which can be dipole-dipole interactions, hydrogen bonds, or even ion-dipole interactions in the case of ionic solutes. These interactions release energy, which helps to offset the energy needed to break the original intermolecular bonds in both the solute and solvent.

The effectiveness of a solvent in dissolving a particular solute depends on the principle "like dissolves like". Polar solvents (like water) are good at dissolving polar solutes or ionic compounds, while nonpolar solvents (like hexane) are better at dissolving nonpolar solutes.