Question

Osmotic potential of a solution is always
(A) Positive
(B) Negative
(C) Zero
(D) Variable

Answer 1

Osmotic potential of a solution could be defined as an estimated value of how freely or abundantly the water molecules could shift in a specific system or environment. The movement of water is from a hypotonic solution to a hypertonic solution across a semipermeable membrane.

Complete answer:
The values of Osmotic potential are represented in kilopascals (kPa) and are symbolized by the Greek letter Psi (Ψ). Osmotic potential can be defined as the measure of the concentration of freely available water molecules in solution. The value of osmotic potential depends on the solute concentration. More the solute concentration, more negative is the value of osmotic potential. The osmotic potential of pure water is zero.

In a plant cell the inner osmotic potential is comparatively more negative than that of the pure water due to high solute concentration in the cytoplasm. The negative value of osmotic potential is significant because due to the difference of the potential, the water content could move from the soil to the cells of plant roots through osmosis. In this process the solution would have a lower concentration and thus more negative osmotic potential as compared to the pure water.

Additionally, the solution with a higher amount of solute molecules shows greater negative values of solute potential. The Osmotic potential plays a crucial role and has major significance in numerous living organisms.

Thus, the correct answer is option ‘B’.

Note: There exists a difference between the osmotic pressure and the osmotic potential. Osmotic pressure is observed when a solution applies a specific pressure to avoid the internal flowing of water transversely semi-permeable membranes while osmotic potential is observed when a specific potential difference is applied by the water molecules to move into a hypertonic solution from a hypotonic solution.