Why is solute potential always negative ? Explain `Psi_(w)=Psi_(s)+Psi_(p)`.

Explanation

If some solute is dissolved in pure water, solution has fewer free water molecules and the concentration of water decreases, reducing its water potential.
Hence, all the solution have a lower water potential than pure water. The magnitude of this lowering is due to dissolution of solute is called solute potential or `Psi_(s). Psi_(s)` is always negative. The more the solute molecules, the lower (more negative) is the solute potential `Psi_(s)` water potential of a cell is affected by both solute and pressure potential.
The relationship can be illustrated as
`{:(,Psi_(w)=Psi_(s)+Psi_(p)),("Where,",Psi_(w)="Water potential,"),(,Psi_(s)="solute potential,"),(,Psi_(p)="pressure potential"):}`