Question

____ aids dissolution because it disperses—or spreads out—the solute more evenly.
temperature
size of the solid
stirring or agitation
pressure

1. choose the best answer.

____ has little effect on the solubility of solids and liquids but does affect the solubility of gas.
pressure
temperature
stirring/agitation
size of the solid

Explanation:

1. Stirring or agitation helps in spreading out the solute more evenly in the solvent, thus aiding dissolution. Temperature affects solubility by changing the kinetic energy of particles, size of the solid affects surface - area to volume ratio for dissolution, and pressure mainly affects gas solubility.
2. Pressure has little effect on the solubility of solids and liquids as they are incompressible. But for gases, Henry's law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid.

Answer:

1. C. Stirring or agitation
2. A. Pressure