A membrane sac filled with large molecules of potassium is suspended in a beaker of water.What will happen?
A) The potassium will leave and the water will enter until both sides reach equal concentrations.
B) Water will enter the sac and it will swell.
C) Because the potassium cannot leave, the water cannot enter.
D) We cannot determine the outcome unless we know the tonicity of the solutions.
E) The potassium will leave the sac and it will shrink.

Question

Quizplus · Accepted Answer

Since the potassium is a large molecule, it cannot cross the membrane. However, the water will enter the sac due to osmosis (moving from a higher concentration outside of the sac to a lower concentration inside the sac). This will cause the sac to swell.

A Membrane Sac Filled with Large Molecules of Potassium Is