In a solution, what is a solute?

A solute is defined as a substance that is dissolved in a solvent to form a solution. In this context, the solute is typically present in a smaller amount compared to the solvent, which is the substance that does the dissolving. For example, when salt (the solute) is added to water (the solvent), the salt dissolves and disperses uniformly throughout the water, creating a saline solution. This fundamental concept is essential for understanding various chemical processes, such as reactions in solution, concentration calculations, and properties of solutions.

The other options relate to different aspects of chemical solutions but do not correctly define a solute. The solvent, for instance, refers specifically to the liquid that facilitates dissolution, while solid formation or gaseous compounds in equilibrium do not pertain to the definitions of solutes. Understanding the role of solutes is crucial in chemistry as it allows for better grasp of solution behavior and interactions.