To increase the concentration of a solution, what should be added?

To increase the concentration of a solution, adding more solute is the most effective approach. Concentration is defined as the amount of solute present in a given quantity of solvent or solution. When more solute is added, it increases the solute's proportion relative to the solvent, thereby raising the solution's overall concentration.

For instance, if you have a saltwater solution and you add additional salt without changing the amount of water, the concentration of salt in the solution becomes greater. The properties of solute and solvent will determine how much solute can be effectively dissolved, but the fundamental principle remains that increasing the amount of solute will always lead to a higher concentration.

While temperature and pressure can influence solubility and therefore might indirectly affect concentration, they do not inherently increase the amount of solute within the solution itself. Additionally, adding more solvent would actually dilute the solution, thereby reducing its concentration.