The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.

At the beginning of the U-tube experiment illustrated above, which of the following statements is true?
A) Side A is hypertonic to side B.
B) Side A is hypotonic to side B.
C) Side A is hypertonic to side B with respect to glucose.
D) Side A is hypotonic to side B with respect to NaCl.

Question

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl) , and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.

At the beginning of the U-tube experiment illustrated above, which of the following statements is true?

At the beginning of the U-tube experiment illustrated above, which of the following statements is true?
A) Side A is hypertonic to side B. 
B) Side A is hypotonic to side B. 
C) Side A is hypertonic to side B with respect to glucose. 
D) Side A is hypotonic to side B with respect to NaCl.

Quizplus · Accepted Answer

At the beginning of the experiment, the solutions in Side A and Side B have different concentrations of glucose and NaCl. Side A has 0.4 M glucose and 0.5 M NaCl, while Side B has 0.8 M glucose and 0.4 M NaCl. Since the volumes are initially the same, the total number of particles (glucose and NaCl) in each side is also the same. However, because the concentrations of glucose and NaCl are different, the number of glucose particles is higher in Side B than in Side A, and the number of NaCl particles is higher in Side A than in Side B. 
Therefore, Side A is hypotonic to Side B, meaning that it has a lower concentration of solutes (glucose and NaCl) compared to Side B.

The Solutions in the Arms of a U-Tube Are Separated