Final answer:
a), The iodine could diffuse due to its smaller molecular size, leading to faster diffusion as compared to the larger starch molecules. Temperature influences the rate of diffusion, with higher temperatures leading to increased molecular energy and faster diffusion. Free diffusion occurs until concentration equilibrium is reached, with the rate decreasing over time.
Step-by-step explanation:
The iodine solution could diffuse out of the tube and into the beaker, while the starch solution could not diffuse into the tube because iodine molecules are smaller and diffuse faster than starch molecules, which are larger and therefore diffuse more slowly. This process is in accordance with how diffusion works, as lighter molecules move more quickly than larger ones, which is explained by the mass of the diffusing molecules having an inverse relationship with their rate of diffusion. In the video illustrating the process of diffusion in solutions, the option that states the lower temperature in the left beaker causes the yellow dye to diffuse slower than in the right beaker with a higher temperature, summarizes how temperature affects the rate of diffusion. Higher temperature increases the energy levels of the molecules, leading to faster diffusion. Diffusion without barriers is known as free diffusion, and as per the provided references, molecules move from a region of high concentration to one of lower concentration until equilibrium is reached. The rate of diffusion is highest at the start and decreases as the concentration gradient diminishes.