If blood cells are placed in a solution containing more than 0.9% (mass/volume) sodium chloride, which of the following is correct?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → All of the above
The fluid inside a blood cell has the same osmotic pressure as a 0.9% (mass/volume) NaCl solution (normal saline). A solution with more than 0.9% NaCl has a higher osmotic pressure than the cell fluid, so solvent moves across the cell membrane from the cell into the solution.
Option (1) Water will flow out of the cells — Correct. Water moves from the cell fluid (lower concentration) into the more concentrated salt solution.
Option (2) The solution is hypertonic — Correct. A salt solution stronger than 0.9% is called hypertonic.
Option (3) The cells would shrink — Correct. The cells lose water and shrink.
All three statements are correct.
NCERT (2026-27 edition):
1.6.4 Osmosis and Osmotic Pressure – “… For example, the osmotic pressure associated with the fluid inside the blood cell is equivalent to that of 0.9% (mass/volume) sodium chloride solution, called normal saline solution and it is safe to inject intravenously. On the other hand, if we place the cells in a solution containing more than 0.9% (mass/ volume) sodium chloride, water will flow out of the cells and they would shrink. Such a solution is called hypertonic.”