What happens to the concentration of a solution during dilution?

During dilution, a solution is mixed with a solvent, typically water, which increases the total volume of the solution. When this occurs, the amount of solute (the substance dissolved in the solvent) remains constant, while the volume of solvent increases.

Concentration is defined as the amount of solute per unit volume of solution. Mathematically, this can be expressed as:

[ \text{Concentration} = \frac{\text{Amount of solute}}{\text{Volume of solution}} ]

As the volume of the solution increases due to the addition of solvent, the ratio of solute to solution volume decreases. Consequently, the concentration of the solute in the solution decreases, which aligns with the option indicating that the concentration decreases. This understanding is essential in chemistry, especially when preparing solutions or in reaction contexts, where the concentration can affect reaction rates and equilibria.