Question

1. What percent of NaCl solution (where the only solute is NaCl) would make it have a higher concentration of diffusible water as a solution with a total osmolarity of 280 mOsm/L?

Please correct #2 to show a net gain of water instead of a net loss.

2. If a one-liter solution contains 280 mOsm of glucose and it also contains 280 mOsm of NaCl, then a red blood cell placed into this solution would experience a net loss of water.

Answer 1

Nacl referred as an electrolyte, substance which ionize to give charged particle in solution. As NaCl completely ionize in water, it refers as a strong electrolyte. 1M of NaCl ionize to give 1M Na and 1M Cl will give 2 osmol NaCl solution.

Osmolarity expressed as concentration of solution in terms of how strongly they will attract water across membrane. Diffusion of water across the membrane called osmosis.

0.9% NaCl will have solution with approx 280mosm/l. 0.9% means 0.154 M which gives approx 280 mosmo/l.

2) if one liter of solution contain no glucose and less than 280mOsm of NaCl then red blood cell placed into this solution would experience net gain of water. In hypotonic solution red blood cell swells as it takes on the water. Net osmolarity of water in blood cell is 300mosmol.