Question

During osmosis, flow of water through a semi-permeable membrane is :

• A. from solution having higher concentration only
• B. from both sides of semi-permeable membrane with equal flow rates
• C. from both sides of semi-permeable membrane with unequal flow rates
• D. from solution having lower concentration only

Answer 1

The Correct Option is C

To understand the process of osmosis and the correct answer to this question, we need to explore the concept of osmosis more deeply.

Osmosis: Osmosis is the movement of water molecules through a semi-permeable membrane. This membrane allows certain molecules or ions to pass through by diffusion and occasionally facilitates more rapid diffusion of water. Osmosis specifically refers to the flow of water from an area of lower solute concentration to an area of higher solute concentration.

The key aspect of osmosis is the semi-permeable membrane, which permits only the solvent (usually water) to pass through while blocking solute particles. This movement continues until the solutions on either side of the membrane reach equilibrium.

Explanation of Answer: In the options given:

1. From solution having higher concentration only
2. From both sides of semi-permeable membrane with equal flow rates
3. From both sides of semi-permeable membrane with unequal flow rates
4. From solution having lower concentration only

Option 3 is the correct answer: From both sides of semi-permeable membrane with unequal flow rates.

Reason: Water flows through the semi-permeable membrane from both directions, but the flow rate from the side of lower concentration (hypotonic solution) to the side of higher concentration (hypertonic solution) is greater. This creates a net movement of water towards the solution with higher concentration, attempting to dilute it and reach equilibrium.

Elimination of Incorrect Options:

• Option 1 is incorrect because water moves from lower to higher solute concentrations.
• Option 2 is incorrect due to the unequal flow rates caused by concentration differences.
• Option 4 is incorrect because water primarily moves from lower to higher concentrations, not just from higher concentrations.

Thus, osmosis involves the movement of water through a semi-permeable membrane, primarily from a region of lower solute concentration to an area of higher solute concentration, with unequal flows from both sides.