1. The problem statement, all variables and given/known data i) A human erythrocyte (red blood cell) may be approximated as a disc around 2 microns in height and with a diameter of 10 microns. If the pressure inside were to become large enough for the cell membrane to rupture, where would you expect it to fail, assuming the membrane is of uniform thickness and composition? ii) The concentration of impermeant ions inside an erythrocye is approximately 2 × 10^26 m^−3. Calculate the osmotic pressure, assuming the cell is at 37◦C. 2. Relevant equations Van't Hoff's law: Osmotic Pressure = nRT/V n= moles of solute particles in solution of Volume V v= volume of RBC = (pi x 5um^2 x 2um) = 157.0796327um^3 = 1.570796327x10^-16 m^3 R= Gas Constant 8.3145 m^3 Pa/Kelvin x Mol T= Temperature in Kelvin 3. The attempt at a solution i) I don't really know what theoretical knowledge I need to answer this but I'm saying that the sides of the blood vessel would rupture (fail) as there is less surface area along them compared to the 10um diameter circle at the top of the cylinder which there is a higher chance for more pressure to act on a specific spot on the sides of the blood vessel which means more chance for that specific spot to fail? Is this correct? ii) So I assume I just whack everything into the equation? Osmotic Pressure = ((8.3145 m^3 Pa/Kelvin x Mol) x 310Kelvin x(2x10^26m^3 )/(1.570796327x10^-16 m^3) = 3.28x10^45 (m^3 Pa/mol) Those units look really wrong so I doubt I worked out the answer correctly. Did I do something wrong? Osmotic pressure normally has just pressure units right so I guess I need to convert some stuff (figure out a way to make the impermeant ion concentration into mols?) Thanks for the help.