Which of the following does NOT increase the rate at which a solid dissolves in water?

• A. Increasing the temperature of the water
• B. Stirring the solution
• C. Decreasing the temperature of the water
• D. Crushing the solid into smaller pieces

Answer: (C)

Verified step by step guidance

1. Understand that the rate at which a solid dissolves in water depends on factors that increase the interaction between the solid and the solvent, such as temperature, surface area, and agitation.
2. Recognize that increasing the temperature of the water generally increases the kinetic energy of molecules, leading to faster dissolution.
3. Know that stirring the solution helps distribute the solute particles throughout the solvent, increasing the rate of dissolution by reducing the concentration gradient near the solid surface.
4. Understand that crushing the solid into smaller pieces increases the surface area exposed to the solvent, which also increases the dissolution rate.
5. Identify that decreasing the temperature of the water reduces molecular motion and kinetic energy, which slows down the dissolution process, so it does NOT increase the rate at which the solid dissolves.