Refer to an experiment in which a dialysis-tubing bag is filled with a mixture of 3% starch and 3% glucose and placed in a beaker of distilled water, as shown below. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot.
(A) The initial concentration of glucose in the bag is higher than the initial concentration of starch in the bag.
(B) The pores of the bag are larger than the glucose molecules but smaller than the starch molecules.
(C) The bag is not selectively permeable.
(D) A net movement of water into the beaker has occurred.
(E) The molarity of the solution in the bag and the molarity of the solution in the surrounding beaker are the same.
Answer: B
From the initial conditions and results described, which of the following is a logical conclusion?
(A) The initial concentration of glucose in the bag is higher than the initial concentration of starch in the bag.
(B) The pores of the bag are larger than the glucose molecules but smaller than the starch molecules.
(C) The bag is not selectively permeable.
(D) A net movement of water into the beaker has occurred.
(E) The molarity of the solution in the bag and the molarity of the solution in the surrounding beaker are the same.
Answer: B