**Correct Option: B. Increasing the surface area of the solid solute** ### Detailed Explanation: To understand why increasing the surface area of a solid solute is the most effective way to increase its solubility in a liquid solvent, we need to consider how solubility works and the factors that influence it. 1. **Solubility Basics**: - Solubility is the ability of a solute (in this case, a solid) to dissolve in a solvent (like water). When a solid dissolves, its particles separate and disperse throughout the solvent. - The process of dissolving involves interactions between the solute and solvent molecules. For a solid to dissolve, the solvent must surround and interact with the solute particles. 2. **Surface Area**: - The surface area of a solid solute refers to the amount of exposed area that is available for interaction with the solvent. - When you increase the surface area (for example, by grinding a solid into a powder), more solute particles are exposed to the solvent at any given time. This allows more solvent molecules to interact with the solute, facilitating the dissolving process. - More interactions lead to a faster rate of dissolution, which can effectively increase the solubility of the solid in the solvent. ### Why Other Options Are Incorrect: A. **Decreasing the temperature of the solvent**: - For most solid solutes, increasing the temperature of the solvent actually increases solubility. This is because higher temperatures provide more energy to the molecules, allowing them to overcome the forces holding the solute particles together. Therefore, decreasing the temperature would likely decrease solubility, making this option incorrect. C. **Reducing the pressure above the solvent**: - Pressure has a significant effect on the solubility of gases, but it has little to no effect on the solubility of solids in liquids. Solids are generally not compressible, and their solubility is not influenced by pressure changes in the same way that gases are. Thus, this option is not relevant to the solubility of solid solutes. D. **Decreasing the agitation of the solution**: - Agitation (stirring or shaking) helps to distribute the solute particles throughout the solvent and can enhance the rate of dissolution. Decreasing agitation would slow down the process of dissolving, making this option counterproductive to increasing solubility. ### Summary of Key Points: - **Increasing surface area** of a solid solute allows more solute particles to interact with the solvent, enhancing the rate of dissolution. - **Temperature** generally increases solubility for solids; decreasing it is not beneficial. - **Pressure** affects gas solubility but not solid solubility in liquids. - **Agitation** promotes dissolution; reducing it slows down the process. ### Revision Summary: - Increasing the surface area of a solid solute enhances its solubility in a liquid solvent. - Higher temperatures typically increase the solubility of solid solutes. - Pressure changes do not significantly affect solid solubility in liquids. - Agitation helps dissolve solids; less agitation decreases the rate of dissolution.