Question

aqueous solutions - 7.6d, 7.6e

which factor affecting the rate of dissolution is being tested with this experiment?
a temperature
b agitation
c surface area
d concentration

Explanation:

In this experiment, the amount of water, the amount of salt, and the temperature are kept constant. The only variable that changes is the agitation (represented by the rpm values). Agitation affects the rate of dissolution by increasing the movement of solvent molecules around the solute, which helps in breaking the solute - solvent interactions and thus speeds up the dissolution process. Temperature (Option A) is constant (\(20^{\circ}C\)) for all beakers. Surface area (Option C) would involve changing the physical state (e.g., powder vs. large chunks) of the solute, which is not the case here as the amount of salt (\(600mg\)) is the same. Concentration (Option D) would involve changing the amount of solute or solvent relative to each other, but the amount of water (\(500mL\)) and salt (\(600mg\)) is constant.

Answer:

B. Agitation