A drop of two dyes, A and B were placed on the surface of gelatin in two test tubes. After 24 hours dye A and B had traveled 2.7 and 1.8 cm below the surface of the gel in their respective tubes. Calculate the diffusion rates. Why dye has a larger molecular weight and why?

To get the diffusion rate, would you just take 2.7-1.8 and divide it by 24 hours? What dye would have a larger molecular weight and why? Thanks