Figure 5.3
The solutions in the arms of a U-tube (Figure 5.3) 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. Refer to the figure to answer the following questions.
-If you examine side A in the figure after three days, the concentrations of glucose and NaCl should be

Question

Quizplus · Accepted Answer

Selective permeable membrane only allows NaCl to pass through. As time goes on, the concentration of NaCl will be equal in both arms. Therefore, the concentration of NaCl in side A would be 0.5 M. For side A to reach an equilibrium with side B, more glucose will have to move to side A to balance the concentration of glucose. Therefore, the concentration of glucose in side A would be higher than the initial 0.4 M, but lower than 0.8 M. Hence, the correct option is C, where the glucose concentration is 0.6 M and the NaCl concentration is 0.45 M.

Figure 5.3 The Solutions in the Arms of a U-Tube (Figure 5.3)