In a colloid osmometer, what does the semipermeable membrane permit?

Prepare for the Clinical Chemistry Automation Test with a comprehensive practice quiz. Study with detailed explanations and multiple choice questions to enhance your understanding and boost your confidence. Ace your exam with our prepared material!

In a colloid osmometer, the semipermeable membrane is selective for solvent over solute. This means water (the solvent) can pass through the membrane, but the dispersed solute particles are blocked. As a result, water moves from the side with lower solute concentration to the side with higher solute concentration, creating osmotic pressure that can be measured. The ability of the membrane to let solvent through while restricting solute passage is what drives and defines osmotic behavior in this setup. If solute could pass, there would be no persistent osmotic pressure to measure; if neither could pass, or if both could pass, flow and pressure would not develop in the same way.