1a.

In a laboratory experiment, a student found that a 103-mL aqueous solution containing 2.987 g of a compound had an osmotic pressure of 25.1 mmHg at 298 K. The compound was also found to be nonvolatile and a nonelectrolyte. What is the molar mass of this compound?

____g/mol

1b.Osmotic pressure, , is calculated according to the equation,

= cRTi

Where: = Osmotic Pressure in atmospheres = 3.30310^-2 atm c = molarity of solute R = Ideal gas constant = 0.0821 L atm mol^-1 K^-1 T = Kelvin temperature = 298 K i = van't Hoff factor = 1 for a nonelectrolyte

Calculate the molarity of solute.

c = _______mol/L

1c. Use the solution volume and calculated molarity to determine the amount (mol) of solute present in the sample. molarity = 1.35110^-3 mol/L volume = 0.1030 L

_______ mol unknown solute

1d. Divide the mass (g) of unknown by the amount (mol) present to determine the molar mass (g/mol) of the unknown. Mass unknown = 2.987 g amount (mol) unknown = 1.39110^-4 mol

________g/mol