The correct option is **B. Pressure applied to the solvent**. ### Detailed Explanation: 1. **Understanding Solubility**: Solubility is the ability of a solute (in this case, a solid) to dissolve in a solvent (a liquid). The extent to which a solid can dissolve in a liquid is influenced by several factors, including temperature, the nature of the solute and solvent, and the physical agitation of the solution. 2. **Analyzing Each Option**: - **A. Temperature of the solvent**: - Temperature plays a significant role in solubility. Generally, for most solid solutes, increasing the temperature of the solvent increases solubility. This is because higher temperatures provide more kinetic energy to the molecules, allowing them to break apart and interact with the solvent more effectively. - **B. Pressure applied to the solvent**: - Pressure has a minimal effect on the solubility of solid solutes in liquids. This is because solids are incompressible, and the solubility of solids is not significantly influenced by changes in pressure. In contrast, pressure has a more pronounced effect on the solubility of gases in liquids, where increasing pressure increases gas solubility. - **C. Nature of the solute and solvent**: - The chemical nature of both the solute and solvent is crucial. Solubility is often determined by the principle "like dissolves like," meaning polar solutes tend to dissolve well in polar solvents, and nonpolar solutes dissolve in nonpolar solvents. The interactions between solute and solvent molecules (such as hydrogen bonding, dipole-dipole interactions, and van der Waals forces) are key to solubility. - **D. Stirring or agitation of the solution**: - Stirring or agitation increases the rate at which a solute dissolves in a solvent. It helps distribute the solute particles throughout the solvent, allowing for more effective interactions between solute and solvent molecules. While it does not change the maximum solubility, it can speed up the process of reaching that solubility. 3. **Why Other Options Are Incorrect**: - **A** is incorrect because temperature significantly affects solubility. - **C** is incorrect because the nature of the solute and solvent is fundamental to understanding solubility. - **D** is incorrect because stirring enhances the dissolution process, even though it does not affect the solubility limit. ### Common Pitfalls: - Students often confuse the effects of pressure on gases versus solids. Remember that pressure primarily affects gas solubility. - Misunderstanding the role of temperature can lead to incorrect assumptions about solubility trends. ### Revision Summary: - **Temperature**: Generally increases solubility of solids in liquids. - **Pressure**: Has little effect on solid solubility; more relevant for gases. - **Nature of solute/solvent**: Critical for determining solubility compatibility. - **Stirring**: Enhances the rate of dissolution but does not change solubility limits.