A white blood cell with an internal solute concentration of 0.9% is placed in a solution of concentrated salt water of 5%. Describe what will happen to the white blood cell in this solution

The 5% salt water is hyperosmotic to the cell’s internal 0.9% solute concentration. The salt (presumably sodium chloride in this case, but this would also apply generally to soluble salts in the chemical sense) in salt water exists as solvated ions; the solutes within the cell’s cytoplasm consist of proteins, nucleus acids, other molecules, and also salts. However, the cell membrane is generally impermeable to all of these substances.

On the other hand, the cell membrane is permeable to water, which can thus diffuse through the cell membrane. An osmotic gradient exists due to the difference in solute concentrations—there is “less” water relative to solutes in salt water than within the cell. Water will thus be pulled out of the white blood cell’s interior and into the external salt water solution. The result will be a shrunken and shriveled white blood cell with an internal solute concentration that is equal (or as close as possible) to the solute concentration of the salt water.