Find the osmotic pressure of the solution: Lets understand how to find the osmotic pressure of a solution when you have given mass using osmotic pressure equation.
(A) Isotonic intervenous solutions contain 49 g/L of glucose .What is the osmotic pressure of blood?Solution A :
Strategy: Isotonic solutions by defination exert equal osmotic pressure.Therefore Π for the blood is same as Π for glucose solution.We can calculate Π from the osmotic pressure equation after converting the concentration into moles per liter.
Step 1: Find the number of moles of glucose :
Molar mass = 180 g/mol (from the formula of glucose C6H12O6) using the mass in grams of glucose given in the problem find the number of moles of glucose:-
Moles of glucose = mass in grams/molar mass
= 48 g/ 180 g/mol = 0.26 moles of glucose
Step 2: Find the molarity of the glucose solution:
Subsitute the number of moles of glucose from step 1 into molarity equation to find the molarity of glucose solution
M = 0.26 moles/ 1 L = 0.26 mol/L
Step 3 : Convert the temperature given in degree celcius to Kelvins:
Because we are working with blood in the human body,T is the human body temperature 37 degree celcius.And as temperature should be in Kelvins we do degree celcius to kelvin conversion:
T = 37 = 273 = 310 K , R= 0.082 L atm/mol K
Step 4: Finally find the osmotic pressure using Π = MRT equation:
Π = 0.272 mol/L * 0.082 l atm/mol K * 310 K
= 6.9 atm