Can you help me? 9) Osmosis helps biological cells maintain their structure. Cell membranes are semipermeableand allow water, small molecules, and hydrated ions to pass, while blocking the passage ofbiopolymers synthesized inside the cell. The difference in concentrations of solutes inside andoutside the cell gives rise to an osmotic pressure, and water passes into the more concentratedsolution in the interior of the cell, carrying small nutrient molecules. The influx of water alsokeeps the cell swollen, whereas dehydration causes the cell to shrink. These effects are importantin everyday medical practice. To maintain the integrity of blood cells, solutions that are injectedinto the bloodstream for blood transfusions and intravenous feeding must be isotonic with theblood, meaning that they must have the same osmotic pressure as blood. If the injected solutionis too dilute, or hypotonic, the flow of solvent into the cells, required to equalize the osmoticpressure, causes the cells to burst and die by a process called hemolysis. If the solution is tooconcentrated, or hypertonic, equalization of the osmotic pressure requires flow of solvent out ofthe cells, which shrink and die.Osmosis also forms the basis of dialysis, a common technique for the removal of impurities fromsolutions of biological macromolecules. In a dialysis experiment, a solution of macromoleculescontaining impurities, such as ions or small molecules (including small proteins or nucleic acids),is placed in a bag made of a material that acts as a semipermeable membrane and the fi lled bagis immersed in a solvent. The membrane permits the passage of the small ions and molecules butnot the larger macromolecules, so the former migrate through the membrane, leaving themacromolecules behind. In practice, purification of the sample requires several changes ofsolvent to coax most of the impurities out of the dialysis bag.Osmometry is the determination of molar mass by the measurement of osmotic pressure. Thesimple form of van't Hoff equation is:II = [B] RTIn this equation the [B] is the molar concentration of solute. So:m[B]VCB/MAMAV In this equation the [B] is the molar concentration of solute. So:пm[B] =CB/MAVMAVWhere cp the mass concentration of the solute is in the total volume of solution and MA is themolar mass of the solute. This equation can be replaced in the previous one to get:RTп-CBMAIn this equation molar mass of given solute can be determined from the slope of the II vs cB plot.This equation applies only to solutions that are sufficiently dilute to behave as ideal-dilutesolutions. In the case of non-ideal solutions, however, the extended formula is:II = [B] RT{1+ k. [B] + n. [B]²Biological macromolecules dissolve to produce solutions that are far from ideal, but we can stillcalculate the osmotic pressure by assuming that the van't Hoff equation is only the first term of alengthier expression:II = [B]RT (1+b. [B])II= RT + bRT. [B][B]IIRT + bRT. CBMAca/MARTbRTCBМАсвMAIn this equation molar mass of given biomolecule can be determined from the intercept ofСвvs. CB plot.The osmotic pressures of solutions of a protein at 25°C were as follows:св0.51.01.52.0 2.5(gL)II (Pa)40.0 112033490What is the molar mass of the protein?

Question

Accepted Answer

1 g/L is equivalent to 1 kg/m3.
 
The given table is:

CB (kg/m3)
Π (Pa)
Π/CB

0.5
40.0
80

1.0…