The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions

The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in a hypertonic sucrose solution.

Explanation:

As the plasma membrane of RBCs allows water and urea to pass through but doesn't allow the sucrose to enter, when the RBC's are placed in hypertonic sucrose solution (a solution which contains excessive amount of sucrose in relation to water) the water from the RBC's will move outside towards the hypertonic sucrose solution because the RBC's are relatively hypotonic as compared to the hypertonic sucrose solution along the concentration gradient (From hypotonic to hypertonic) and the sucrose cannot enter the RBC's as the plasma membrane of RBC's don't allow.

As the water is lost from the RBC's they start to shrink.