Calculate the osmotic pressure, in mm Hg, and freezing-point depression, in $\Delta$°C, of an aqueous solution at $25°C$ that contains $3.5\times { 10 }^{ -3 }g/mL$ of a polysaccharide with molar mass of $1.3\times { 10 }^{ -5 }g/mol$, and the density of the solution is $1.01 \ g/cm^{3}$.

The molal freezing-point depression constant for water is $1.86 \ °C \cdot \frac{kg}{mol}$.