Solution:
Water potential is the difference in the free energy or chemical potential per unit molal volume of water in a system and that of pure water at the same temperature and pressure. Water potential is represented by Greek letter \(\Psi\) (psi) or \(\Psi_{w}\) Water potential is the sum total of \(\Psi_{s}\) and \(\Psi_{p}\). Therefore, \(\Psi_{w}=\Psi_{s}+\Psi_{w}\).
