Question

Define water potential.

Answer 1

Water potential:-

1. At constant temperature and pressure, the difference in free energy present in the water of a system when compared with the free energy of pure water is called water potential.
2. Water potential is the potential energy of the water in a device relative to pure water, as both temperature and pressure are constant.

Important points related to water potential:

1. It is measured in kPa (kilopascals) and is expressed by Ψ (Psi - A Greek letter).
2. Water potential is never positive but has a maximum value of zero, that is, at atmospheric pressure, it is pure water.
3. The more negative it is when it comes to impure water or water that has solutes in it, as the solute molecules attract water molecules and limit their freedom to travel.