Describe how the molarity of sucrose affects the mass of the potato core. Describe the difference in mass when the molarity of sucrose is 0.0 M and when it is 1.0 M. The student hypothesized that the mass of the potato cores would increase as the molarity of sucrose increases. Use the data to evaluate this hypothesis. Describe water potential and explain how movement of water molecules across a membrane is affected by concentration gradients.