You can choose from the following questions to test: How does particle size affect the rate of solution formation? How does the temperature of the solvent affect the rate of solution formation? You should only choose from the materials suggested to complete your experiment, which include: water at different temperatures (be careful when working with hot liquids), cups or bowls, coarse and/or fine salt, sugar cubes and/or granulated sugar, measuring cup, teaspoon, measuring cup, stopwatch.