Question

What will be the direction of the movement of water when two solutions with ${\Psi }_w=0.2MPa$ and ${\Psi }_w=0.1MPa$ are separated by a selectively permeable membrane?

Answer 1

• Chemical potential is a quantitative expression of the free energy associated with a substance. So water potential or the chemical potential of the water represents the free energy associated with water. It is denoted as Ψw.
• Without any energy investment, water flows from regions of higher chemical potential to ones of lower chemical potential. So, in this case, net water movement occurs in the direction from solution with ${\psi }_w$=0.2M Pa to the solution with ${\psi }_w$=0.1M Pa (higher to lower).