Question
How is osmotic pressure related to the concentration of the solution?
Solution
Answer:
osmotic pressure is proportional to the molarity, C of the solution at a given temperature T. thus
Π = C R T
Here Π is the osmotic pressure and R is the
gas constant.
Π = (n2 /V) R T
Here V is volume of a solution in litres containing n2 moles of solute.
If w2 grams of solute, of molar mass, M2 is present in the solution, then
n2 = w2 / M2 and we can write
Thus, knowing the quantities w2, T, Π and V we can calculate the molar mass of the solute.
