Question

What is osmosis? How does it differ from diffusion?

Answer 1

Hint: In diffusion, the movement of solute and solvent molecules takes place whereas osmosis is a special kind of diffusion. In osmosis movement only that component of a solution takes place which is usually present in larger quantities.

Complete answer:
Osmosis is the net movement of water molecules having a certain amount of kinetic energy across a partially permeable membrane. The phenomena in which the two solutions of two different concentrations are separated by the semi-permeable membrane. It is responsible for the gain and loss of water in the cell. The water molecules of the water move from their higher concentration to their lower concentration until the concentration of both the solution becomes equal.

Additional Information:
- Osmosis is caused by a concentration difference of water.
- If the substance is dissolved in water, the kinetic energy of the water molecules is lowered because some water molecules aggregate on the surface of the other molecules.
- When the water has another substance dissolved in it results the water molecules have less potential to move, this is negative osmotic potential.
- Water molecules always move from less negative to more negative water potential to balance the concentration.

Note:
- The osmotic potential of a cell is known as its water potential; that is for animal cells, the water potential is the osmotic potential of the cytoplasm.
- The osmotic potential of distilled water has a high potential that is zero.
- Reverse osmosis is a type of osmosis that helps to convert sewage water into clean water.