Final answer:
Crushing a solid increases the rate at which it dissolves because it creates more surface area for the solvent to interact with the solute particles, leading to a faster dissolution.
Step-by-step explanation:
Crushing a solid increases the speed at which the solid dissolves because it increases the surface area exposed to the solvent. This is a fundamental concept in Chemistry concerning the rate of dissolution. When a solid is crushed into smaller pieces, more of its surface area is in contact with the solvent, which allows more solvent molecules to collide with the solute. Surface area plays a crucial role because dissolution occurs at the surface where the solute and solvent interact. The smaller the particles, the more surface area is available, leading to an increase in the rate at which the solute dissolves. Therefore, the correct answer to the student's question is (b) It increases the surface area exposed to the solvent.