Why do most solids become more soluble in water with increasing temperature? (Hint: Think about what happens to the water molecules as temperature increases.)

Solubility is defined as the maximum amount of solute (usually a solid) that can be dissolved in a solvent (usually a liquid) to form a homogenous solution at a given temperature and pressure. In this exercise, we are focusing on the solubility of solids in water.

As the temperature of water increases, water molecules gain kinetic energy and begin to move more rapidly and with more collisions. The increased movement of water molecules causes the average distance between them to increase, and this provides more space for solute particles to fit among the solvent particles.

Most solids dissolve in water through a process called dissolution, which is an endothermic process (requires the absorption of heat or energy). When the temperature of the water increases, the increased kinetic energy of the water molecules helps break the bonds between the solute particles more efficiently. This allows the solute particles to separate and disperse evenly throughout the water. Furthermore, the increased movement of the water molecules also helps to create stronger interactions between the solute particles and the water molecules, forming new bonds. These new bonds help to keep the solute particles separated and distributed throughout the solution. Since the solubility of most solids in water increases with temperature due to an increase in the kinetic energy of water molecules and the increased efficiency of both the bond-breaking and bond-forming processes during dissolution, we can conclude that most solids become more soluble in water with increasing temperature. So, the answer to the exercise is: Most solids become more soluble in water with increasing temperature because the enhanced kinetic energy of water molecules due to increased temperature helps dissolve the solid more efficiently and promotes stronger interactions between solute particles and water molecules.