Question

calculate the freezing point and osmotic pressure at 25 degrees celcious of an aqueous solution containing 1.0 g/L of a protein (mm=9.0*10^4g/mol) if the density of the solution is 1.0 g/cm^3

Answer 1

Note the correct spelling of celsius.
delta T = kf*molality
Calculate delta T (then freezing point) knowing Kf and molality.
molality = moles/kg solvent. You have kg solvent (but you will need to use the density) and moles = g/molar mass.

For osmotic pressure, pi = MRT.
don't forget to change T to Kelvin.