Question

What happens when RBCs are placed in
(a) 0.5% NaCl solution
(b) 1% NaCl solution

Answer 1

Hint: The spontaneous net movement or diffusion of solvent molecules through a selectively permeable membrane from a region of high water potential (lower solute concentration) to a region of low water potential (higher solute concentration) in the direction that tends to equalise the solute concentrations on the two sides is referred to as osmosis. It can also refer to a physical process in which any solvent passes through a selectively permeable barrier (permeable to the solvent but not to the solute) that separates two solutions with differing concentrations.

Complete answer:
A hypertonic solution contains more solutes than a non-hypertonic solution. In biology, a solution's tonicity relates to its solute concentration in comparison to another solution on the other side of a cell membrane; a solution outside of a cell is hypertonic if it has a higher solute concentration than the cytosol within the cell. When a cell is submerged in a hypertonic solution, osmotic pressure causes water to flow out of the cell to keep the concentrations of solutes on each side of the cell membrane balanced. The cytosol, on the other hand, is hypotonic, which is the polar opposite of the outer solution. Hypotonic solution with 0.5 percent NaCl causes RBC to expand and rupture owing to the difference in osmotic pressure.

The concentration of solutes in a hypotonic solution is lower than in another solution. If a solution outside of a cell has a lower concentration of solutes than the cytoplasm, it is called hypotonic in biology. Water diffuses into the cell as a result of osmotic pressure, causing the cell to appear turgid or bloated. If the gradient is big enough, the absorption of extra water by cells without a cell wall, such as animal cells, can create enough pressure to cause cytolysis, or cell rupturing. A 1% NaCl solution is a hypertonic solution that causes RBC cells to shrink.

Note: The water potential of two solutions separated by a semipermeable cell membrane is measured by tonicity, which is a measure of the effective osmotic pressure gradient. To put it another way, tonicity refers to the relative concentration of dissolved solutes in a solution that determines the direction and extent of diffusion. It's a term that's often used to describe how cells react when they're submerged in a solution.