What is Osmosis?
Movement of water molecules from the region of higher concentration to the region of lower concentration of molecules through semi-permeable membrane until equilibrium is attained is called osmosis.
Why is osmotic potential given a negative sign?
Osmotic potential is the decrease in the chemical potential due to deposition of solute particles in the solution. It is the total number of solute particles present in the volume of a solution. Osmotic potential is directly proportional to the osmotic pressure and both are quantitatively equal. However, osmotic pressure has positive sign while osmotic potential has negative sign.