Osmosis from one fluid compartment to another is determined by:
The temperature difference between the compartments
The relative concentration of the solutes in each compartment
The relative volume in each compartment
The relative size of each compartment
The correct answer and explanation is :
The correct answer is:
The relative concentration of the solutes in each compartment.
Explanation:
Osmosis is the passive movement of water molecules across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration. The primary factor that determines the direction and rate of osmosis is the concentration gradient of solutes between two fluid compartments, not temperature, volume, or compartment size.
- Concentration Gradient (Relative Concentration of Solutes):
The concentration difference between two compartments (i.e., how much solute is dissolved in each compartment) is the key driving force behind osmosis. Water naturally moves to where the solute concentration is higher, in an attempt to dilute that compartment and reach equilibrium. This movement occurs across a selectively permeable membrane, which allows water to pass through but blocks most solutes.
- Hypertonic Solution: If one compartment has a higher solute concentration (hypertonic solution) than the other (hypotonic solution), water will move from the lower solute concentration to the higher solute concentration to balance the solute levels.
- Isotonic Solution: If both compartments have the same concentration of solutes (isotonic solutions), there is no net movement of water.
- Temperature Difference: While temperature can influence the rate of osmosis (higher temperatures generally increase the rate of osmosis), it is not the determining factor in whether osmosis occurs or not. Osmosis is driven by the concentration gradient, not by temperature differences between compartments.
- Volume and Compartment Size: The volume or size of the compartments doesn’t directly affect the osmotic process itself. However, if the compartments are large or have different volumes, the net movement of water may have different consequences, but this is secondary to the concentration gradient.
Thus, osmotic pressure, which is driven by solute concentration, is the main factor in determining the flow of water between fluid compartments.