Which of the following would decrease the rate at which a solid dissolves in water?

• A. Increasing the amount of water used
• B. Stirring the solution more vigorously
• 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 such as surface area, temperature, agitation (stirring), and the amount of solvent.
2. Recognize that increasing the amount of water generally increases the solvent available, which can increase the dissolution rate or at least not decrease it.
3. Know that stirring the solution more vigorously increases the interaction between the solid and solvent molecules, thus increasing the dissolution rate.
4. Understand that crushing the solid into smaller pieces increases the surface area exposed to the solvent, which increases the rate of dissolution.
5. Realize that decreasing the temperature of the water reduces the kinetic energy of the molecules, slowing down the dissolution process and thus decreasing the rate at which the solid dissolves.