solute into smaller pieces B. decreasing the temperature of the solvent C. increasing the amount of solute D. leaving the solute undisturbed in the solvent
Which of the following will increase the rate at which a solute dissolves? A. breaking up or crushing the solute into smaller pieces B. decreasing the temperature of the solvent C. increasing the amount of solute D. leaving the solute undisturbed in the solvent
The Correct Answer and Explanation is:
Correct Answer: A. Breaking up or crushing the solute into smaller pieces
Explanation:
The rate at which a solute dissolves in a solvent depends on several factors, including the surface area of the solute, temperature of the solvent, and agitation (stirring). Among the options given, breaking up or crushing the solute into smaller pieces (Option A) is the most effective way to increase the rate of dissolution.
When a solute is broken into smaller pieces, its surface area increases. A greater surface area means more solute particles are exposed to the solvent, allowing more interactions between the solute and solvent molecules. This increased contact speeds up the dissolving process. For example, granulated sugar dissolves much faster than sugar cubes because it has more surface area in contact with the water.
On the other hand:
- Option B: Decreasing the temperature of the solvent will actually slow down the rate of dissolution for most solids. Higher temperatures provide more kinetic energy to the solvent molecules, causing them to move faster and collide more effectively with the solute, thus speeding up dissolution. Lowering the temperature reduces this effect.
- Option C: Increasing the amount of solute does not increase the rate of dissolving; in fact, if the solution is nearing saturation, it can make it harder for additional solute to dissolve. The rate is more influenced by conditions affecting how well the solute and solvent interact.
- Option D: Leaving the solute undisturbed in the solvent typically leads to slower dissolution because there is no agitation or stirring to help disperse the solute particles and increase contact with the solvent.
Therefore, Option A is the correct answer because increasing the surface area of the solute enhances its interaction with the solvent, leading to faster dissolution.
