Which of the following colligative properties is useful to determine the molar masses of proteins, polymers, or colloids with the greatest precision?

Which among the following colligative properties is useful to determine molar masses of very expensive solutes?

$15 \%$ aqueous solution of glucose (molecular weight $= 180 \ g/mol$) is isotonic with $8 \%$ aqueous solution containing an unknown non-dissociable solute. What is the molecular weight of the unknown solute?

An artificial cell is made by encapsulating $0.2 \ M$ glucose solution within a semipermeable membrane. The osmotic pressure developed when the artificial cell is placed within a $0.05 \ M$ solution of $NaCl$ at $300 \ K$ is . . . . . . . . . .$\times 10^{-1} \ bar$. (Nearest Integer)
[Given : $R=0.083 \ L \ bar \ mol^{-1} \ K^{-1}$ ]
Assume complete dissociation of $NaCl$.

What is a "semi-permeable membrane"?

At constant temperature,the osmotic pressure of a solution is: