Two compartments are separated by a membrane that is permeable to water and urea.Compartment I contains 1 M NaCl.Compartment II contains 2 M urea.Which of the following is a correct statement of their relationship based on the initial conditions?

Question

Quizplus · Accepted Answer

Isosmotic refers to solutions having the same osmotic pressure, and hypertonic refers to a solution having a higher osmotic pressure than another solution across a semipermeable membrane. Given that both NaCl and urea dissociate or are effective in osmotic balance, and without specific information on their dissociation or osmotic coefficients, it's reasonable to consider their total molar concentrations for osmotic pressure comparison. Both compartments have the same total solute concentration (1 M NaCl is equivalent to 2 osmoles due to dissociation into Na+ and Cl-, and 2 M urea is 2 osmoles), making them isosmotic. However, the question's phrasing suggests considering osmotic pressures, where typically NaCl would exert a higher osmotic pressure due to ionization compared to urea, which does not ionize, potentially making compartment I hypertonic to II. This explanation assumes a simplistic view without detailed osmotic coefficients, leading to the selection of both A and C as correct under different interpretations.

Two Compartments Are Separated by a Membrane That Is Permeable