Answer:
a) 0.046 mol/L
b) 0.016 mol
c) 271.58 g/mol
Explanation:
A nonelectrolyte solute is a solute that, when dissolved in a solvent, will not make the solution a conductor, and so the electricity will not pass through it. The osmotic pressure is a colligative property, and it's the pressure difference needed to stop the flow of a solution across a semipermeable membrane. It can be calculated by:
π = MRT
Where π is the osmotic pressure, M is the molarity of the solute (mol/L), R is the ideal gas constant, and T is the temperature (in K). For a pressure in torr, R = 62.3637 torr.L/(mol.K).
a) π = MRT , T = 25°C = 298 K
851 = M*62.3637*298
18584.3826M = 851
M = 0.046 mol/L
b) The number of moles of the solute (n) is the molar concentration (molarity) multiplied by the volume. So, for a solution of 345 mL = 0.345 L,
n = 0.046 * 0.345
n = 0.016 mol
c) The molar mass (MM) is the mass divided by the number of moles:
MM = 4.31/0.016
MM = 271.58 g/mol
