Which of the following usually makes a substance dissolve faster in a solvent?

A: lowering the temperature
B: decreasing the number of particles
C: agitating the solution
D: increasing the particle size of the solute

To determine which factor usually makes a substance dissolve faster in a solvent, let's analyze each option:

A: Lowering the temperature. Generally, decreasing the temperature of a solvent reduces the rate of dissolution. This is because lower temperatures slow down the kinetic energy of the particles involved, reducing the likelihood of effective collisions between the solute and solvent particles. As a result, solubility typically decreases when the temperature is lowered.

B: Decreasing the number of particles. Decreasing the number of particles of a solute does not usually promote faster dissolution. Increasing the concentration of a solute would provide a greater number of solute particles, typically leading to faster dissolution.

C: Agitating the solution. Agitating or stirring a solution can indeed accelerate the dissolution process. By continuously stirring the solution, you increase the interaction between the solute and solvent particles, effectively removing the solute molecules from the surface and allowing fresh solvent molecules to come into contact with the solute. This facilitates a quicker dissolution process.

D: Increasing the particle size of the solute. Increasing the particle size of the solute generally slows down the dissolution process. Larger particles expose less surface area to the solvent, reducing the number of solvent-solute interactions. Consequently, finer particles, with increased surface area, dissolve faster.

From these options, C: agitating the solution is usually the factor that makes a substance dissolve faster in a solvent.

C: agitating the solution

What do you know about dissolving substances with and without stirring. What about large particles versus small particles? How does the temperature affect the solubility?